Showing posts with label Lab Values. Show all posts
Showing posts with label Lab Values. Show all posts
Feb 6, 2013
Dec 23, 2011
Glucose Testing....
Glucose
Also known as:
Blood sugar; Fasting blood sugar; FBS; Fasting blood glucose; FBG;
Fasting plasma glucose; FPG; Blood glucose; Oral Glucose Tolerance Test;
OGTT; GTT; Urine glucose
Formal name: Blood Glucose; Urine Glucose
At a Glance
Why Get Tested?
To determine if your blood glucose level is within a healthy range; to screen for, diagnose, and monitor high blood glucose (hyperglycemia) or low blood glucose (hypoglycemia), diabetes, and pre-diabetes; to check for glucose in your urine
When to Get Tested?
Blood glucose: as part of a regular physical, when you have symptoms suggesting hyperglycemia or hypoglycemia, and during pregnancy; if you are diabetic, self-checks up to several times a day to monitor blood glucose levels
Urine glucose: usually as part of a urinalysis
Urine glucose: usually as part of a urinalysis
Sample Required?
A blood sample drawn from a vein in your arm or a drop of blood from a skin prick; sometimes a random urine sample
is used. Some diabetic patients may use a continuous glucose monitor,
which is a small sensor wire inserted beneath the skin of the abdomen
that measures blood glucose every five minutes.
Test Preparation Needed?
In
general, it is recommended that you fast - nothing to eat or drink
except water - 8 hours before having a blood glucose test. In persons
with diabetes, glucose levels are often checked both while fasting and
after meals to provide the best control of diabetes. For random, timed,
and post-meal glucose tests, follow your doctor's instructions.
The Test Sample
What is being tested?
This
test measures the amount of glucose in the blood or urine. Glucose is
the primary energy source for the body’s cells and the only energy
source for the brain and nervous system. A steady supply must be
available for use, and a relatively constant level of glucose must be
maintained in the blood.
During digestion, fruits, vegetables, breads and other carbohydrates are broken down into glucose (and other nutrients); they are absorbed by the small intestine and circulated throughout the body. Using glucose for energy production depends on insulin, a hormone produced by the pancreas. Insulin facilitates transport of glucose into the body's cells and directs the liver to store excess energy as glycogen for short-term storage and/or as triglycerides in adipose (fat) cells.
Normally, blood glucose rises slightly after a meal and insulin is released by the pancreas into the blood in response, with the amount corresponding to the size and content of the meal. As glucose moves into the cells and is metabolized, the level in the blood drops and the pancreas responds by slowing, then stopping the release of insulin.
If the blood glucose level drops too low, such as might occur in between meals or after a strenuous workout, glucagon (another pancreatic hormone) is secreted to induce the liver to turn some glycogen back into glucose, raising the blood glucose level. If the glucose/insulin feedback mechanism is working properly, the amount of glucose in the blood remains fairly stable. If the balance is disrupted and the glucose level in the blood rises, then the body tries to restore the balance, both by increasing insulin production and by eliminating excess glucose in the urine.
There are a few different conditions that may disrupt the balance between glucose and the pancreatic hormones, resulting in high or low blood glucose. The most common cause is diabetes. Diabetes is a group of disorders associated with insufficient insulin production and/or a resistance to insulin. People with untreated diabetes are not able to process and use glucose normally. Those who are not able to produce enough insulin to process glucose are diagnosed as having type1 diabetes while people who are resistant to insulin have type 2. Either type of diabetic may have acute and/or chronically increased blood glucose levels.
Severe, acute high blood glucose (hyperglycemia) or low blood glucose (hypoglycemia) can be life-threatening, causing organ failure, brain damage, coma, and, in extreme cases, death. Chronically high blood glucose levels can cause progressive damage to body organs such as the kidneys, eyes, heart and blood vessels, and nerves. Chronic hypoglycemia can lead to brain and nerve damage.
Some women may develop hyperglycemia during pregnancy, which is termed gestational diabetes. If untreated, this can cause these mothers to give birth to large babies who may have low glucose levels. Women who have had gestational diabetes may or may not go on to develop diabetes.
During digestion, fruits, vegetables, breads and other carbohydrates are broken down into glucose (and other nutrients); they are absorbed by the small intestine and circulated throughout the body. Using glucose for energy production depends on insulin, a hormone produced by the pancreas. Insulin facilitates transport of glucose into the body's cells and directs the liver to store excess energy as glycogen for short-term storage and/or as triglycerides in adipose (fat) cells.
Normally, blood glucose rises slightly after a meal and insulin is released by the pancreas into the blood in response, with the amount corresponding to the size and content of the meal. As glucose moves into the cells and is metabolized, the level in the blood drops and the pancreas responds by slowing, then stopping the release of insulin.
If the blood glucose level drops too low, such as might occur in between meals or after a strenuous workout, glucagon (another pancreatic hormone) is secreted to induce the liver to turn some glycogen back into glucose, raising the blood glucose level. If the glucose/insulin feedback mechanism is working properly, the amount of glucose in the blood remains fairly stable. If the balance is disrupted and the glucose level in the blood rises, then the body tries to restore the balance, both by increasing insulin production and by eliminating excess glucose in the urine.
There are a few different conditions that may disrupt the balance between glucose and the pancreatic hormones, resulting in high or low blood glucose. The most common cause is diabetes. Diabetes is a group of disorders associated with insufficient insulin production and/or a resistance to insulin. People with untreated diabetes are not able to process and use glucose normally. Those who are not able to produce enough insulin to process glucose are diagnosed as having type1 diabetes while people who are resistant to insulin have type 2. Either type of diabetic may have acute and/or chronically increased blood glucose levels.
Severe, acute high blood glucose (hyperglycemia) or low blood glucose (hypoglycemia) can be life-threatening, causing organ failure, brain damage, coma, and, in extreme cases, death. Chronically high blood glucose levels can cause progressive damage to body organs such as the kidneys, eyes, heart and blood vessels, and nerves. Chronic hypoglycemia can lead to brain and nerve damage.
Some women may develop hyperglycemia during pregnancy, which is termed gestational diabetes. If untreated, this can cause these mothers to give birth to large babies who may have low glucose levels. Women who have had gestational diabetes may or may not go on to develop diabetes.
How is the sample collected for testing?
A
blood sample is obtained by inserting a needle into a vein in the arm or
a drop of blood is taken by pricking the skin, typically on a finger,
with a small, pointed lancet (fingerstick). Sometimes, a random urine sample
is collected. Some diabetics may use a continuous glucose monitor,
which is a small sensor wire inserted beneath the skin of the abdomen
and held in place with an adhesive patch. The sensor measures blood
glucose levels every five minutes and sends the results to a device that
is attached to the person's clothing. A digital readout on the device
lets the person know the blood glucose level in real time.
Is any test preparation needed to ensure the quality of the sample?
For
screening purposes, fasting is generally recommended - nothing to eat
or drink except water - at least 8 hours before a blood glucose test.
Those who have been diagnosed with diabetes and are monitoring glucose
levels are often tested both while fasting and after meals. For random
and timed tests, follow the doctor's instructions. A glucose tolerance
test requires that you fast for the first blood sample and then drink a
liquid containing a specified amount of glucose. Subsequent blood
samples are drawn at specified times.
The Test
How is it used?
The blood glucose test may be used to:
Screening
Blood glucose is often measured as part of a group of tests, such as a CMP (Comprehensive Metabolic Panel), during routine physicals. This is done to screen for diabetes, which often causes no symptoms early in its course, and for pre-diabetes – moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes. For screening purposes, a CMP or blood glucose test is performed on a fasting basis (fasting blood glucose, FBG).
Many pregnant women are screened for gestational diabetes, a temporary form of hyperglycemia, between their 24th and 28th week of pregnancy using a version of the OGTT, a 1-hour glucose challenge (GCT). For this test, a woman is given a standard amount of a glucose solution to drink. After one hour, her glucose level is measured and if the level is higher than a defined value, then a longer OGTT (usually 2 or 3 hours) is performed to clarify the woman's status. This is the recommendation of the American Congress of Obstetricians and Gynecologists.
In 2011, the American Diabetes Association adopted guidelines that recommend changes in the way women are tested for gestational diabetes. Instead of the GCT described above, a 2-hour OGTT, using a 75-gram glucose drink, is performed. If one or more of her glucose levels at fasting, 1 hour, or 2 hours are above a certain level, then she is diagnosed as having gestational diabetes.
The ADA’s new recommendations follow those proposed in 2010 by the International Association of Diabetes and Pregnancy Study Group (IADPSG). This group based their recommendations on results of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) trial. This large study found that risk to babies increases with the gradual increase of maternal glucose levels; it determined that there is an increased risk of adverse outcomes for a baby even when only one of the mother’s glucose levels is below the cutpoints used to diagnose gestational diabetes, and slightly lowered some of the cutpoints from those used in older guidelines. (For more on this, read the article Panel Suggests New Criteria for Gestational Diabetes.)
Diagnosis
The American Diabetes Association recommends a fasting glucose or a different test, the hemoglobin A1c (A1c), to diagnose diabetes but says that testing should be done twice, at different times, preferably with the same test in order to confirm a diagnosis of diabetes. Another way to diagnose diabetes, especially if the screening test is not diagnostic, is the OGTT test. This test is a series of blood glucose tests. A fasting glucose is collected; then the person being tested drinks a standard amount of a glucose solution to "challenge" their system. This is followed by one or more additional glucose tests performed at specific intervals to track glucose levels over time.
In those with suspected hypoglycemia in which an initial FBG result is low, the glucose test is used as part of the "Whipple triad" to confirm a diagnosis. (See Common Questions #5).
Monitoring
Diabetics must monitor their own blood glucose levels, often several times a day, to determine how far above or below normal their glucose is and to determine what oral medications or insulin(s) they may need. This is usually done by placing a drop of blood from a skin prick onto a glucose strip and then inserting the strip into a glucose meter, a small machine that provides a digital readout of the blood glucose level.
Urine
Urine glucose is one of the substances tested when a urinalysis is performed. A urinalysis may be done routinely as part of a physical or prenatal checkup, when a doctor suspects that a person may have a urinary tract infection or for a variety of other reasons. The doctor may follow up an elevated urine glucose test with blood glucose testing.
- Screen for both high blood glucose (hyperglycemia) and low blood glucose (hypoglycemia)
- Help diagnose diabetes
- Monitor glucose levels in persons with diabetes
Screening
Blood glucose is often measured as part of a group of tests, such as a CMP (Comprehensive Metabolic Panel), during routine physicals. This is done to screen for diabetes, which often causes no symptoms early in its course, and for pre-diabetes – moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes. For screening purposes, a CMP or blood glucose test is performed on a fasting basis (fasting blood glucose, FBG).
Many pregnant women are screened for gestational diabetes, a temporary form of hyperglycemia, between their 24th and 28th week of pregnancy using a version of the OGTT, a 1-hour glucose challenge (GCT). For this test, a woman is given a standard amount of a glucose solution to drink. After one hour, her glucose level is measured and if the level is higher than a defined value, then a longer OGTT (usually 2 or 3 hours) is performed to clarify the woman's status. This is the recommendation of the American Congress of Obstetricians and Gynecologists.
In 2011, the American Diabetes Association adopted guidelines that recommend changes in the way women are tested for gestational diabetes. Instead of the GCT described above, a 2-hour OGTT, using a 75-gram glucose drink, is performed. If one or more of her glucose levels at fasting, 1 hour, or 2 hours are above a certain level, then she is diagnosed as having gestational diabetes.
The ADA’s new recommendations follow those proposed in 2010 by the International Association of Diabetes and Pregnancy Study Group (IADPSG). This group based their recommendations on results of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) trial. This large study found that risk to babies increases with the gradual increase of maternal glucose levels; it determined that there is an increased risk of adverse outcomes for a baby even when only one of the mother’s glucose levels is below the cutpoints used to diagnose gestational diabetes, and slightly lowered some of the cutpoints from those used in older guidelines. (For more on this, read the article Panel Suggests New Criteria for Gestational Diabetes.)
Diagnosis
The American Diabetes Association recommends a fasting glucose or a different test, the hemoglobin A1c (A1c), to diagnose diabetes but says that testing should be done twice, at different times, preferably with the same test in order to confirm a diagnosis of diabetes. Another way to diagnose diabetes, especially if the screening test is not diagnostic, is the OGTT test. This test is a series of blood glucose tests. A fasting glucose is collected; then the person being tested drinks a standard amount of a glucose solution to "challenge" their system. This is followed by one or more additional glucose tests performed at specific intervals to track glucose levels over time.
In those with suspected hypoglycemia in which an initial FBG result is low, the glucose test is used as part of the "Whipple triad" to confirm a diagnosis. (See Common Questions #5).
Monitoring
Diabetics must monitor their own blood glucose levels, often several times a day, to determine how far above or below normal their glucose is and to determine what oral medications or insulin(s) they may need. This is usually done by placing a drop of blood from a skin prick onto a glucose strip and then inserting the strip into a glucose meter, a small machine that provides a digital readout of the blood glucose level.
Urine
Urine glucose is one of the substances tested when a urinalysis is performed. A urinalysis may be done routinely as part of a physical or prenatal checkup, when a doctor suspects that a person may have a urinary tract infection or for a variety of other reasons. The doctor may follow up an elevated urine glucose test with blood glucose testing.
When is it ordered?
Blood glucose testing can be used to screen healthy, asymptomatic individuals for diabetes and pre-diabetes
because diabetes is a common disease that begins with few symptoms.
Screening with a glucose test may occur during public health fairs or as
part of workplace health programs. It may also be ordered when someone
has a routine physical exam. Screening is especially important for
people at high risk of developing diabetes, such as those with a family
history of diabetes, those who are overweight, and those who are more
than 40 to 45 years old.The glucose test may also be ordered to help diagnose diabetes when someone has symptoms of high blood glucose (hyperglycemia), such as:
- Increased thirst, usually with frequent urination
- Fatigue
- Blurred vision
- Slow-healing infections
- Sweating
- Hunger
- Trembling
- Anxiety
- Confusion
- Blurred Vision
Pre-diabetes is characterized by fasting or OGTT levels that are higher than normal but lower than those defined as diabetic. The doctor may order a glucose test at regular intervals to monitor the person's status.
With known diabetics, doctors will order glucose levels periodically in conjunction with other tests such as A1c to monitor glucose control over time. Occasionally, a blood glucose level may be ordered along with insulin and C-peptide to evaluate insulin production.
Diabetics are often required to self-check their glucose, up to several times a day, to monitor glucose levels and to determine treatment options as prescribed by their doctor.
Pregnant women are usually screened for gestational diabetes late in their pregnancies, unless they have early symptoms or have had gestational diabetes with a previous pregnancy. When a woman has gestational diabetes, her doctor will usually order glucose levels throughout the rest of her pregnancy and after delivery to monitor her condition.
What does the test result mean?
Blood Glucose
High levels of glucose most frequently indicate diabetes, but many other diseases and conditions can also cause an elevated blood glucose. The following information summarizes the meaning of the test results. These are based on the clinical practice recommendations of the American Diabetes Association.
Moderately increased blood glucose levels may be seen in those with pre-diabetes. Left un-addressed, pre-diabetes increases the risk of developing type 2 diabetes.
Some other diseases and conditions that can result in an elevated blood glucose level include:
A low blood glucose level (hypoglycemia) may be seen with:
Low to undetectable urine glucose results are considered normal. Any condition that raises blood glucose such as diabetes or the other conditions listed above also has the potential to elevate the concentration of glucose in the urine.
Increased urine glucose may be seen with medications, such as estrogens and chloral hydrate, and with some forms of kidney disease.
High levels of glucose most frequently indicate diabetes, but many other diseases and conditions can also cause an elevated blood glucose. The following information summarizes the meaning of the test results. These are based on the clinical practice recommendations of the American Diabetes Association.
Fasting Blood Glucose
| Glucose Level | Indication |
|---|---|
| From 70 to 99 mg/dL (3.9 to 5.5 mmol/L) | Normal fasting glucose |
| From 100 to 125 mg/dL (5.6 to 6.9 mmol/L) | Impaired fasting glucose (pre-diabetes) |
| 126 mg/dL (7.0 mmol/L) and above on more than one testing occasion | Diabetes |
Oral Glucose Tolerance Test (OGTT)
| Glucose Level | Indication |
|---|---|
| Less than 140 mg/dL (7.8 mmol/L) | Normal glucose tolerance |
| From 140 to 200 mg/dL (7.8 to 11.1 mmol/L) | Impaired glucose tolerance (pre-diabetes) |
| Over 200 mg/dL (11.1 mmol/L) on more than one testing occasion | Diabetes |
Gestational Diabetes Screening: Glucose Challenge Test (as currently recommended by the American Congress of Obstetricians and Gynecologists)
| Glucose Level | Indication | ||
|---|---|---|---|
| Less than 140* mg/dL (7.8 mmol/L) | Normal screen | ||
| 140* mg/dL (7.8 mmol/L) and over | Abnormal, needs OGTT (see below) | ||
| * Some use a cutoff of 130 mg/dL (7.2 mmol/L) because that identifies 90% of women with gestational diabetes, compared to 80% identified using the threshold of 140 mg/dL (7.8 mmol/L). | |||
Gestational Diabetes Diagnostic: OGTT
| Time of Sample Collection | Current ACOG Target LEVEL | ADA Target Level |
|---|---|---|
| Glucose load: Samples drawn after 100-gram glucose drink | Glucose load: Samples drawn after 75-gram glucose drink | |
| Fasting (prior to glucose load) | 95 mg/dL (5.3 mmol/L) | 92 mg/dL (5.1 mmol/L) |
| 1 hour after glucose load | 180 mg/dL (10.0 mmol/L) | 180 mg/dL (10.0 mmol/L) |
| 2 hours after glucose load | 155 mg/dL (8.6 mmol/L) | 153 mg/dL (8.5 mmol/L) |
| 3 hours after glucose load | 140 mg/dL (7.8 mmol/L) | Not applicable |
| Results interpretation | If TWO or more values meet or exceed the target level, gestational diabetes is diagnosed. | If ONE or more values meet or exceed the target level, gestational diabetes is diagnosed. |
Some other diseases and conditions that can result in an elevated blood glucose level include:
- Acromegaly
- Acute stress (response to trauma, heart attack, and stroke for instance)
- Chronic kidney failure
- Cushing syndrome
- Excessive food intake
- Hyperthyroidism
- Pancreatic cancer
- Pancreatitis
A low blood glucose level (hypoglycemia) may be seen with:
- Adrenal insufficiency
- Drinking excessive alcohol
- Severe liver disease
- Hypopituitarism
- Hypothyroidism
- Insulin overdose
- Insulinomas
- Starvation
Low to undetectable urine glucose results are considered normal. Any condition that raises blood glucose such as diabetes or the other conditions listed above also has the potential to elevate the concentration of glucose in the urine.
Increased urine glucose may be seen with medications, such as estrogens and chloral hydrate, and with some forms of kidney disease.
Is there anything else I should know?
Extreme stress can cause a temporary rise in blood glucose. This can be a result of trauma, surgery, heart attack or stroke, for example.
Drugs, including corticosteroids, tricyclic antidepressants, diuretics, epinephrine, estrogens (birth control pills and hormone replacement), lithium, phenytoin, and salicylates, can increase glucose levels, while drugs such as acetaminophen and anabolic steroids can decrease levels.
Drugs, including corticosteroids, tricyclic antidepressants, diuretics, epinephrine, estrogens (birth control pills and hormone replacement), lithium, phenytoin, and salicylates, can increase glucose levels, while drugs such as acetaminophen and anabolic steroids can decrease levels.
Common Questions
Related Pages
On This Site
Conditions: Diabetes, Kidney Disease, Pancreatic Diseases, Thyroid Diseases, Cushing Syndrome
Screening: Diabetes - Children (2-12), Teens (13-18), Young Adults (19-29), Adults (30-49), Adults (50 and up)
In the News: Together, Two Tests Better Predictors of Progression to Diabetes (2011), Studies Evaluate A1c for Diagnosing Diabetes (2011), Use of A1c Point-of-Care Tests for Diabetes Screening Raises Concerns (2011), CDC and FDA Issue Alerts for Point-of-Care Testing (2010), Panel Suggests New Criteria for Gestational Diabetes (2010), ADA recommends A1c test to diagnose diabetes and pre-diabetes (2010), FDA issues alert about glucose monitoring test strips and meters (2009), Experts Recommend that Hemoglobin A1c also be used to Diagnose Diabetes (2009), Estimated Average Glucose: A New Term in Diabetes Control (2009)
Screening: Diabetes - Children (2-12), Teens (13-18), Young Adults (19-29), Adults (30-49), Adults (50 and up)
In the News: Together, Two Tests Better Predictors of Progression to Diabetes (2011), Studies Evaluate A1c for Diagnosing Diabetes (2011), Use of A1c Point-of-Care Tests for Diabetes Screening Raises Concerns (2011), CDC and FDA Issue Alerts for Point-of-Care Testing (2010), Panel Suggests New Criteria for Gestational Diabetes (2010), ADA recommends A1c test to diagnose diabetes and pre-diabetes (2010), FDA issues alert about glucose monitoring test strips and meters (2009), Experts Recommend that Hemoglobin A1c also be used to Diagnose Diabetes (2009), Estimated Average Glucose: A New Term in Diabetes Control (2009)
Elsewhere On The Web
College of American Pathologists: MyHealthTestReminder.com - Diabetes Tests
American Academy of Family Physicians: Diabetes - Blood tests to help manage your diabetes
Nemours Foundation: Blood test - Glucose
American Diabetes Association
American Association of Diabetes Educators: Patient Resources
Centers for Disease Control and Prevention: Diabetes Public Health Resource
National Institute of Diabetes and Digestive and Kidney Diseases: Diabetes
National Diabetes Education Program: Know your Blood Sugar Numbers
American Academy of Family Physicians: Diabetes - Blood tests to help manage your diabetes
Nemours Foundation: Blood test - Glucose
American Diabetes Association
American Association of Diabetes Educators: Patient Resources
Centers for Disease Control and Prevention: Diabetes Public Health Resource
National Institute of Diabetes and Digestive and Kidney Diseases: Diabetes
National Diabetes Education Program: Know your Blood Sugar Numbers
Article Sources
(Revised 2011 February). Know your Blood Sugar Numbers. National
Diabetes Education Program [On-line information]. PDF available for
download at http://ndep.nih.gov/media/knownumbers_eng.pdf through http://ndep.nih.gov. Accessed May 2011.
Olatunbosun, S. (Updated 2011 April 19). Glucose Intolerance. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/119020-overview through http://emedicine.medscape.com. Accessed May 2011.
Dugdale, D. (Updated 2010 May 23). Glucose test – blood. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003482.htm. Accessed May 2011.
Olatunbosun, S. (Updated 2011 April 19). Glucose Intolerance. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/119020-overview through http://emedicine.medscape.com. Accessed May 2011.
Dugdale, D. (Updated 2010 May 23). Glucose test – blood. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003482.htm. Accessed May 2011.
Reference Ranges and What They Mean.....
The "Normal" or Reference Range
"Your test was out of the normal range," your doctor says to you, handing you a sheet of paper with a set of test results, numbers on a page. Your heart starts to race in fear that you are really sick. But what does this statement mean, "Out of the normal range"? Is it cause for concern? The brief answer is that a result out of the normal or reference range is a signal that further investigation is needed.
The term "normal range" is not used very much today because it is considered to be misleading. If a patient's results are outside the range for that test, it does not automatically mean that the result is abnormal. Therefore, today "reference range" or "reference values" are considered the more appropriate terms, for reasons explained on the next page. The term reference values is increasing in use and is often used interchangeably with reference range. For simplicity, we use the term reference range in this article.
Tests results—all medical data—can only be understood once all the pieces are together. Take one of the simplest medical indicators of all—your heart rate. You can take your resting heart rate right now by putting your fingers on your pulse and counting for a minute. Most people know that the "average" heart rate is about 70 beats per minute. How do you know what a "normal" heart rate is? We know this on the basis of taking the pulse rate of millions of people over time.
You probably also know that if you are a regular runner or are otherwise in good physical condition, your pulse rate could be considerably lower—so a pulse rate of 55 could also be "normal." Say you walk up a hill—your heart rate is now 120 beats a minute. That would be high for a resting heart rate but "normal" for the rate during this kind of activity.
Your heart rate, like any medical observation, must be considered in context. Without the proper context, any observation or test result is meaningless. To understand what is normal for you, your doctor must know what is normal for most other people of your age and what you were doing at the time—or just before—the test or observation was conducted.
The interpretation of any clinical laboratory test must consider this important concept when comparing the patient's results to the test's "reference range."
What is a reference range?
Some tests provide a simple yes or no answer. Was the culture positive for strep throat? Did the test find antibodies to a virus that indicates an infection?But for many more tests, the meaning of the results depends on their context. A typical lab report will provide your results followed by a reference range. For example, your results for a thyroid-stimulating hormone (TSH) test might look something like: 2.0 mIU/L, ref range 0.5 – 5.0 mIU/L. The test results indicate that it falls within the reference range.
How was that reference range established? The short answer is: by testing a large number of healthy people and observing what appears to be "normal" for them.
The first step in determining a given reference range is to define the population to which the reference range will apply, for example, healthy females between 20 and 30 years old. A large number of individuals from this category would be tested for a specific laboratory test. The results would be averaged and a range (plus or minus 2 standard deviations of the average) of normal values would be established.
The term "reference range" is preferred over "normal range" because the reference population can be clearly defined. Rather than implying that the test results are being compared with some ill-defined concept of "normal," the reference range means the results are being considered in the most relevant context. When you examine test results from different populations, you quickly discover that what is "normal" for one group is not necessarily normal for another group. For example, pregnancy changes many aspects of the body's chemistry, so pregnant women have their own set of reference ranges.
Effects of Age and Sex
For many tests, there is no single reference range that applies to everyone because the tests performed may be affected by the age and sex of the patient, as well as many other considerations. Some examples of variation in reference ranges based on age:- Alkaline phosphatase is an enzyme found in the cells that make bone, so its concentration in the body rises in proportion to new bone cell production. In a child or adolescent, a high alkaline phosphatase level is not only normal but desirable—the child should be growing healthy bones. But these same levels found in an adult are a sign of trouble—osteoporosis, metastatic bone disease (extra bone growth associated with tumors), or other conditions. It is because of these significant variations due to age that the few reference ranges that you may see on this site do not include ranges for children or adolescents. Experience from testing large numbers of people has led to different reference ranges by age group.
- Hemoglobin and hematocrit (a red blood cell measure) both decline as a natural part of the aging process.
- Creatinine is produced as a natural by-product of muscle activity and is removed from your bloodstream by your kidneys. Creatinine levels will be affected by a person's muscle mass as well as their kidney function. It is often measured as a gauge of how well your kidneys are functioning. Because males have greater muscle mass than females, the reference range for males is higher than for females.
- The enzyme creatine kinase (CK) and one of its forms called CK-MB present a similar situation. CK is released into the bloodstream by damaged muscles; CK-MB is released into the bloodstream when the heart muscle is damaged. Therefore, a high level of CK-MB indicates damage to the heart muscle, so this enzyme is one of the indicators used to diagnose heart attacks. Because of their greater muscle mass, men tend to have higher CK levels and the level of CK-MB that indicates a heart attack in men is higher than for women. When the test first came into use, the reference range was based on the higher levels. Many elderly women being tested for a heart attack demonstrated considerably lower levels of CK-MB (because of their smaller muscle mass) and, thus, did not pass the threshold level believed to indicate a heart attack; so heart attacks were often missed in these women.
Other Factors Affecting Test Results
Laboratories will generally report your test results accompanied by a reference range keyed to your age and sex, if appropriate. Your physician then will still need to interpret the results based on personal knowledge of your health status, including any medications or herbal remedies you may be taking. A plethora of additional factors can affect your test results: your intake of caffeine, tobacco, alcohol, and vitamin C; your diet (vegetarian vs. carnivorous); stress or anxiety; or a pregnancy. Even your posture when the sample is taken can affect some results, as can recent heavy exertion. For example, albumin and calcium levels may increase when shifting from lying down to an upright position.Factors such as occupation, altitude, and distance from the ocean have been known to affect results. Regular exercise can also affect values of certain tests; in particular, levels of creatine phosphokinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) will increase. Additionally, testosterone, luteinizing hormone (LH), and platelet levels can increase in people who participate for months and years in strenuous exercise such as distance running and weightlifting.
All these considerations underscore the significance of taking blood or urine samples in a standardized fashion for performing and interpreting laboratory tests (and home tests as well). It is important to comply with your doctor's instructions in preparing for the test, such as coming in first thing in the morning, before you eat anything, to get your blood drawn. That compliance makes your sample as close as possible to others; it keeps you within the parameters of your reference group.
When "Normal" Doesn't Matter
For some tests, such as cholesterol, rather than worry about the reference range, the vast majority of people need only be concerned if their test result falls above or below a cut-off value that is sometimes referred to as a "decision point". If, for example, as studies have shown, a cholesterol level of 200 milligrams per deciliter is the cut-off where heart disease risk should trigger medical intervention, then it doesn't really matter if this result falls into a statistically "normal" range.There are additional tests for which the "normal" range is irrelevant. In testing for the amount of a drug in the blood of an unconscious person, for example, the doctor will interpret the result in terms of the likely effects of the drug at the detected level, not in terms of a reference range.
In addition, clinically significant, dramatic changes in a person's test values, even if those values remain within the reference range for that test, should be brought to the doctor's attention.
What does it mean if my test result is out of the reference range?
First, there are a few reasons why a test result could fall outside of the established reference range despite the fact that you are in good health:- Statistical variability: Even when performing the same test on the same sample multiple times, 1 out of 20 (or 5%) determinations will fall outside an established range, based on the laws of probability. Sometimes, if the test is repeated on this same sample, the result will then be within range.
- Biological variability: If a doctor runs the same test on you on several different occasions, there's a good chance that one result will fall outside a reference range even though you are in good health. For biological reasons, your values can vary from day to day. That is why a doctor may repeat a test on you and why he may look at results from prior times when you had the same test performed.
- Individual variability: References ranges are usually established by collecting results from a large population and determining from the data an expected average (mean) result and expected differences from that average (standard deviation). There are individuals who are healthy but whose tests results, which are normal for them, do not always fall within the expected range of the overall population.
However, a result outside the range may indicate a problem and warrant further investigation. Your doctor will evaluate your test results in the context of your medical history, physical examination, and other relevant factors to determine whether a result that falls outside of the reference range means something significant for you. He may reorder the test. Perhaps the analyte being measured happened to be high that day due to one of the reasons stated previously or perhaps something went awry with the sample (the blood specimen was not refrigerated, or the serum was not separated from the red cells, or it was exposed to heat). Your doctor may also compare the latest test result to previous results if you have been tested for the same thing in the past to get a better idea of what is normal for you.
Laboratories will generally report the findings based on age and sex when appropriate and leave it to the physician to interpret the results based on factors such as diet, your level of activity, or medications you are taking. If you have a result that falls outside the reference range, talk to your doctor about what it means for you and what steps need to be taken next.
If you know of any special circumstances that could affect a test, mention them to your doctor; don't assume your doctor has thought of every possible circumstance.
Why are so few reference ranges included on this web site?
With all this talk of reference ranges, you may notice that few of the test descriptions on this web site include the reference range. There are several reasons for this:
- In general, reference ranges are specific to the laboratory that produces the test results. For many analytes, different laboratories use different kinds of equipment and different kinds of testing methods. This means that each laboratory must establish its own reference ranges using data from its own equipment and methods. The laboratory must supply your test result with an accompanying reference range on the laboratory report. Consequently, there is no such thing as a standard reference range. Of course, each test does have a theoretical reference range that we could include on this site, which can be found in many books and other online sources, but it may have little diagnostic meaning for you. You and your doctor should apply the reference range supplied by the laboratory performing the test. That being the case, however, for a few specific tests, such as the electrolytes, there is a high degree of consistency if not standardization, among clinical laboratories in the methodologies and procedures used for these particular tests. These laboratory methods have been in use for many years now so their reference ranges have been well-established and typically reflect numbers that are very similar to the theoretical reference range. Because of this greatly reduced variability in the reference ranges for these select number of tests, their reference ranges are included on this site. The source of the range for each test is Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, a well-respected and authoritative textbook on the subject that is used by medical professionals.
- You may notice that the few select reference ranges listed here are specific for adults only and there are no ranges included for children or adolescents. The reason is that from infancy throughadolescence, a child's body goes through many changes and growing cycles. Several things that are tested in a laboratory such as chemical levels, hormones, etc. vary greatly as a child goes through the different growth stages. The laboratory where your child's sample is tested has established reference ranges for the different stages of child development. Theoretical reference ranges exist for children, but they are numerous and do not lend themselves to easy interpretation, so they are not included on this site. The best source of information regarding your child's lab test results is your child's doctor.
- For a few other analytes, such as cholesterol, glucose, and prostate specific antigen, there has been a major effort to standardize the laboratory test methods and report formats. The result has been the establishment of a set of cut-off numbers that are different from reference ranges in that they reflect clinical decision points rather than a statistically "normal" range. We have included the published targets in our discussions of these few tests.
- We want you to be informed, but we don't pretend to take the place of communication with your doctor. We want you to understand what the test is for, but because we can't be aware of all the factors that could affect your test results, we can’t interpret the results without more information. If you need further explanation of your results, you should talk to your doctor. This remains true even for those tests, such as the components of the basic metabolic panel (BMP), for which we have included reference ranges. Remember, a reference range is merely a guide for your doctor. He or she will interpret the result in the context of your medical history and current presentation – something that no web site is yet able to do.
Common Misconceptions
There are two main misconceptions about test results and reference ranges:Myth: "An abnormal test result is a sign of a real problem."
Truth: A test result outside the reference range may or may not indicate a problem—the only sure signal it sends is that your doctor should investigate it further. You can have an abnormal value and have nothing wrong—but your doctor should try to determine the cause.
It's possible that your result falls in that 5% of healthy people who fall outside the statistical reference range. In addition, there are many things that could throw off a test without indicating a major problem: High blood sugar could be diet-related rather than caused by diabetes. A lipid result could be high because you didn't fast before the test. High liver enzymes can be the temporary result of a recent drinking binge rather than a sign of cirrhosis. New drugs come on the market constantly, faster than laboratories can evaluate whether they might interfere with test results. It is not uncommon for many of these drugs to interfere with certain laboratory tests, resulting in falsely high or low values.
Most likely, your doctor will want to rerun the test. Some abnormal results may disappear on their own, especially if they are on the border of the reference range. Your doctor will also seek explanations for an abnormal result, such as those above. A key point your doctor will address is, how far out of the reference range is the result?
If these investigations point to a problem, then your doctor will address it. But there are very few medical questions that can be answered by a single test.
Myth: "If all my test results are normal, I have nothing to worry about."
Truth: It's certainly a good sign, but it's only one set of tests, not a guarantee. There is a large overlap among results from healthy people and those with diseases, so there is still a small chance that there is an undetected problem. Just as some healthy people's results fall outside the reference range, lab test results in some people with disease fall within the reference range.
If you're trying to follow a healthy lifestyle, take it as a good sign, and keep it up. But if you're engaging in high-risk behavior, such as drug and alcohol abuse or a poor diet, it only means "so far so good," and the potential consequences haven't caught up with you yet. A good test result is not a license for an unhealthy lifestyle.
If you had abnormal results previously, normal results certainly provide good news. But your doctor may want to conduct follow-up tests some months later to make sure you're still on track and to document any trends.
Article Sources
Link Source Here...
Internet:
National Cholesterol Education Program website, available online through http://www.nhlbi.nih.gov
Cornell University Veterinary School website, available online through http://web.vet.cornell.edu
Sep 6, 2011
Nursing Center Article.. Health-Related Quality of Life in Adults With Hodgkin's Disease: The State of the Science
Hodgkin's
disease (HD), a malignancy of the lymphatic system, occurs in a bimodal
age distribution, with one large incidence in young adults between the
ages of 15 and 40 years and another incidence in those older than 55
years. Through the advancement of diagnostic techniques and treatment
modalities, HD has evolved from a condition that was once frequently
fatal to one that is highly curable. In the 1940s, less than 15% of
patients with HD lived 10 years after diagnosis. Major developments in
therapeutic approaches throughout the 1960s and 1970s-including the use
of radiation and combined radiation and chemotherapy-have dramatically
improved survival. According to the Lymphoma Information Network,
patients with HD diagnosed in its early stages now have a greater than
90% chance of long-term survival and patients diagnosed in the later
stages of disease have an 80% or greater chance of survival.1
Hodgkin's
disease and its treatment are not, however, without consequence to the
survivor. Medical management for HD, although effective against the
cancerous cells, also causes multiple sequelae, including cardiac and
lung toxicity, infertility, and various secondary malignancies.2,3 Such sequelae may affect the survivor's health-related quality of life (HRQOL) for many years after treatment is completed.4
The
purpose of this article was to present an integrative review of
empirical studies designed to examine HRQOL in adult survivors of HD, as
well as to offer suggestions for further study with this population.
For this review, the concept of HRQOL encompasses the impact of the
diagnosis and treatment on the individual survivor's well-being in
physical, psychological, social/functional, and spiritual domains.5,6
Methods
Ganong's7
guidelines for narrative integrative literature reviews direct
researchers to select hypotheses or research questions to focus the
review. Researchers also must identify inclusion criteria for the
research to be reviewed, examine the characteristics of the selected
studies and findings, and interpret the results of the selected
literature. These guidelines were followed to compile, review, and
integrate the literature describing HRQOL in adult survivors of HD.
The final sample encompassed 35 studies (see Table 1), 14 conducted in the United States8-21 and 21 conducted in European countries, including the United Kingdom.22-42
The research questions were addressed using content analysis to
identify and classify study characteristics, including conceptual or
theoretical framework used to guide the study, type of research design
used (correlational or experimental, cross-sectional or longitudinal,
prospective or retrospective, cohort or case-control), sample size,
sampling strategy (probability, nonprobability), source used to recruit
study participants (tumor registry, hospital records), sample
demographic characteristics (gender, age), stage of cancer and years
treated, number of years after diagnosis or treatment completion, when
data were collected, research instruments used, method of administration
of instruments, domains of HRQOL (physical, psychological,
social/functional, spiritual) studied, and summary of findings. Two
members of the review team examined, extracted, and analyzed relevant
information from each of the 35 studies. The 2 team members reached
consensus on selection of the final sample of studies based on the above
characteristics.
 | Table 1 Summary of Studies Examining HRQOL in HD Survivors |
 | Table 1 continued |
 | Table 1 continued |
 | Table 1 continued |
 | Table 1 continued |
 | Table 1 continued |
 | Table 1 continued |
 | Table 1 continued |
Results
Conceptual or Theoretical Framework
Just 2 of the 35 studies were guided by an explicit conceptual or theoretical framework. Cameron et al11 used classical conditioning theory42
to examine the prevalence of persistent aversive symptoms, such as
anticipatory nausea and vomiting, in HD survivors. Wettergren et al42 cited the Wilson and Cleary's Model43 of causal relationships between individuals' health characteristics and HRQOL outcomes.
Study Design
Thirty-four of the 35 studies (97%) were correlational,8-38,40-42 and one was experimental.39 Thirty of 35 studies (86%) were retrospective and cross-sectional.8-14,16-22,24,26-28,30-38,40-42 Just 5 of the 35 studies (14%) used longitudinal, prospective designs.15,23,25,29,39 Twenty of the 35 studies (57%) were case-control, and 15 (43%) were cohort studies.
Sample
Sample
size ranged from 42 to 818 participants. In 15 (43%) studies, the
sample included fewer than 100 participants. A nonprobability
convenience sampling strategy was used for all studies. Participants
were enrolled in the studies using hospital-based records and/or tumor
registries. All but 2 of the study reports9,11
provided information about the numbers of patients who were eligible
but did not participate. Study participants ranged in age from teens to
mid-80s; reports of 2 studies did not include an age range.37,38 In 26 (74%) of the studies, 51% to 60% of the participants were male. Only 6 studies8,12,20,21,26,28 included more female than male participants, and 3 studies9,10,13
included only male participants. Twenty-nine (83%) studies focused on
HRQOL in HD survivors who were more than 1 year but less than 35 years
after treatment completion, and 6 (17%) studies focused on HRQOL of
those newly diagnosed or less than 1 year after treatment completion.13,15,23-25,27 A complete description of the diagnostic stages and treatment regimens was included in all but 4 studies.20,21,23,24
Early-stage disease was defined as stage I-II, and late stage, as stage
III-IV. In one study, further extent of disease was defined by
delineating between the absence (substage A) or presence (substage B) of
key prognostic indicators including fever, night sweats, or pruritus to
differentiate between early- and late-stage disease.13
Twenty-seven (77%) studies were conducted in samples with early- and
late-stage disease. Study samples were treated from 1965 to 2003. Length
and type of treatment were dependent on stage of disease and ranged
from 3 to 18 months for the studies in this review.
Research Instruments
A
total of 29 different instruments were used to measure HRQOL in adult
HD survivors; the most commonly used instruments are listed in Table 2. Ten (29%) studies used researcher-constructed questionnaires,8,10,11,13,14,18,22-24,31 and the remainder used valid and reliable standardized instruments (Table 2).
The instruments were administered most frequently as questionnaires
that were mailed or administered via a telephone or face-to-face
interview.
 | Table 2 The Most Commonly Used Instruments |
Domains of HRQOL
The variables reflecting the domains of HRQOL addressed in this integrative literature review are listed in Table 3.
Twenty-seven of the 35 studies (77%) addressed the physical domain
using variables such as fatigue, sexuality, and cognition. Twenty-six
(74%) studies addressed the psychological domain using variables such as
distress, depression, and anxiety. The social/functional domain was
addressed in 16 (46%) studies; variables included relationships, work,
and activities of daily living. The spiritual domain was addressed in
only 2 of the 35 studies (6%)13,42 by focusing on survivors' worldview and life meaning.
 | Table 3 The 4 Domains and Associated Variables to Measure Health-Related Quality of Life |
Physical Domain
FATIGUE
Fatigue remains a common problem for HD survivors, even several years after the completion of treatment. Hjermstad et al29
found that a sample of 476 HD survivors reported higher levels of
fatigue than a sample drawn from a general, healthy population.
Correlates
of fatigue reported by HD survivors include age, education, gender, HD
stage, type of treatment, and the presence of other physical symptoms.
Loge et al36
reported that total fatigue was significantly higher among survivors 60
years or older compared to younger HD survivors. Participants with
fewer years of education also reported greater fatigue than those with
more years of education. Norum and Wist38
found that men reported significantly higher levels of fatigue than
women did. In addition, patients diagnosed with later stages of disease
and those who received combination cancer therapy (both chemotherapy and
radiation therapy) experienced a greater delay in the return of their
energy levels than those who were diagnosed with earlier stages of
disease and those who received monotherapy.14 Furthermore, patients who received combination therapy reported a higher level of fatigue than those who received monotherapy.15,28 In addition, Norum and Wist38
found that patients who received mantle radiation experienced more
fatigue and dyspnea than those who did not receive radiation up to 10
years after completion of treatment.
In
one study, so-called B symptoms, such as fever, night sweats, and
weight loss at diagnosis, were found to be the only defining disease
characteristics that were positively correlated with survivors' fatigue
after treatment.29
In other studies, survivors' reports of cardiac disease, psychiatric
disease, tobacco use, and low exercise frequency were correlated with
relatively high levels of fatigue after treatment.20,40
ANTICIPATORY NAUSEA AND VOMITING
Anticipatory nausea and vomiting are another common physical problem experienced by HD survivors.11,12,17 According to Cameron et al,11
this conditioned response-a feeling of distress experienced in relation
to the typical sights and/or smells in the medical environment-has been
reported by as many as 55% of survivors at one point in time and is
most likely to occur just after diagnosis but may continue up to 2 years
after treatment. Furthermore, Kornblith et al16
reported that 39% of HD survivors continued to experience nausea for at
least a year after treatment in response to sights and smells, but
episodes of vomiting were a rarer occurrence.
OTHER SYMPTOMS
Hodgkin's
disease survivors experience several other symptoms related to the
treatment received in the years after treatment including cardiovascular
and respiratory complications,20,38 shortness of breath and tachycardia,8 and thyroid dysfunction.32 Nevertheless, Adams et al8
reported that although HD survivors reported moderate to severe
problems with fatigue, shortness of breath, chest pain, and dizziness
several years after treatment completion, they scored their health as
good as or better than that before diagnosis.
SEXUALITY
Some researchers studied survivors' sexuality. Cella and Tross13
found significantly lowered motivation for intimacy among 60 male HD
survivors compared with a healthy control group. Kornblith et al18
noted that 37% of 273 HD survivors reported one or more sexual
problems; the most common were decreased interest in sex and loss of
sexual satisfaction. Fobair et al14
found that the most common sexuality problems were infertility and
decreased interest in sexual activity in a sample of 403 HD survivors.
Greil et al28
found that survivors who had received combination therapy reported more
infertility problems and less sexual enjoyment than did those who had
received monotherapy.
COGNITION
A few researchers have studied cognition in HD survivors. Joly et al31
found that cognitive problems manifested as memory impairment and poor
concentration even several years after treatment completion. Similarly,
Devlen et al23
reported that 47 of 120 HD survivors described having difficulty
recalling simple facts, such as their telephone number, after completing
treatment. These memory impairments were attributed to the older age of
the samples and to depression, anxiety, and possibly minor brain damage
secondary to chemotherapy or viral infection during treatment.
Psychological Domain
DISTRESS
The incidence of emotional distress among HD survivors varied across the 35 studies. Cella and Tross13
reported that survivors did not differ significantly from case-controls
with regard to emotional distress. The findings of other studies,
however, revealed that emotional distress was higher in the survivors
than in healthy populations.18,19
Correlates
of emotional distress include gender, stage of HD, and marital status.
Female HD survivors in one study reported lower levels of distress than
their male counterparts did, manifested as symptoms associated with
posttraumatic stress disorder, such as intrusive thinking and avoidance.37 In contrast, male HD survivors in another study reported less emotional distress after treatment than females did.27
Furthermore, HD survivors diagnosed with later stages of disease (stage
IIB, IIIB, IVA, or IVB) were found to be at higher risk for emotional
distress than those diagnosed with earlier stages.13 And HD survivors who were married had lower levels of distress than those who were not married.21
ANXIETY AND DEPRESSION
It
is estimated that up to 50% of HD patients and survivors report anxiety
and/or depression during the first year after diagnosis and treatment.24 The influence of gender on reports of anxiety and depression is unclear. Although both Zabora et al21 and Fobair et al14 reported no correlation between gender and depression in HD survivors, Loge et al34
noted that anxiety was greater for women than for men. Age and
educational level may be related to anxiety and depression. Kornblith et
al17
found that survivors older than 40 years had a higher incidence of
depression than their younger counterparts, and both Loge et al33 and Kornblith et al17
found that HD survivors with limited educational backgrounds
experienced higher levels of anxiety and depression than those with
higher levels of education. Marital status, however, does not seem to be
related to anxiety and depression. Loge et al34 found no significant difference in anxiety and depression between HD survivors who lived alone and those who were married.
Social/Functional Domain
Although
it is common for HD survivors to return to their usual level of
functioning after treatment is completed, many experience changes in
their ability to function in social and occupational roles.14,18,24,41 For example, difficulty returning to work has been reported in up to 42% of HD survivors.14
Many HD survivors who had trouble returning to work noted that they had
a diminished capacity to complete work-related tasks or adjust to the
work environment.10
In addition, when compared to survivors of testicular cancer, HD
patients were significantly more likely to change jobs or stop working.
Flechtner et al25 reported that the main reason for unemployment among HD survivors was early retirement due to the disease and its treatment.
Several
factors associated with permanent disability after treatment have been
identified, including having little education and low income, having
been treated with combined chemotherapy and radiation therapy, being
older than 40 years, having depression and/or anxiety, and having
experienced exertional dyspnea and pain or stiffness in the shoulders
secondary to mantle field radiation.22,40 Gender also influences function. Fobair et al14 reported that women had a greater decrease in activity tolerance after treatment for HD compared to men. Similarly, Loge et al35 found that women survivors scored lower than men did on a measure of the functional domain of HRQOL.
In
addition, stage of HD may influence functioning. Survivors who had been
diagnosed with later stage HD were found to be at highest risk for
functional adjustment problems, such as readapting to premorbid work
schedules during the first 2 years after treatment.13 In contrast, Devlen et al23
found that a large proportion of survivors of both early- and
late-stage HD failed to return to work and to resume normal leisure
activities up to 1 year after completion of treatment. Hodgkin's disease
survivors experienced a greater decrease in leisure and work activities
than did those who had testicular cancer, which was attributed to
limited energy and type of treatment.10
The
physical domain symptom of fatigue has been found to affect HD
survivors' ability to participate in leisure activities for many months
after treatment. Devlen et al23
noted that 48 of the 120 survivors (40%) surveyed continued to report
little interest in leisure activities even 1 year after the completion
of treatment.
Several
researchers identified changes in marital status, with an increased
incidence of divorce and separation, among HD survivors.22,25
Approximately 20% of participants in one study reported changes in
their relationships that they associated with their cancer diagnosis and
treatment.25
Participants in another study reported having fewer children after
diagnosis and treatment for HD compared with healthy controls.31
Spiritual Domain
Only
2 of the 35 studies (6%) addressed the spiritual domain of HRQOL. In
one study, survivors reported that they had a greater appreciation for
life after treatment.13
In the other study, survivors identified family, personal health, work,
and relationships with close friends as the most important aspects of
their lives after HD diagnosis and treatment.42
Discussion
State of the Science
Although
it is encouraging to know that HD is considered a curative illness, the
potential for overtreatment of young adults diagnosed with HD is a
topic of discussion and concern. The long-term impact of curative
treatment on the physical domain of HRQOL is especially problematic for
young adult HD survivors because of factors such as age at the time of
chest irradiation and the use of alkylating chemotherapy agents that
increase the risk of secondary lung and other cancers and cardiac
disease in long-term survivors. In 1988, clinical researchers explored
treatment reductions intended to reduce life-threatening adverse events
caused by radiation while maintaining cure rates. By 1991, this fifth
novel treatment regimen-named Stanford V for late-stage
disease-shortened treatment courses, instituted cumulative toxic dose
reductions, and decreased radiation doses and volume while maintaining
favorable survival outcomes for HD.44
Consequently, current clinical trials have been designed to determine
the efficacy of treatment reductions in patients with lower radiation
therapy doses and less toxic chemotherapy regimens for earlier stage
disease as the risk for late mortality from causes other than HD
continues to threaten survivors many years later.3
However, until more clinical data support favorable long-term HRQOL
outcomes with treatment reductions in early- and late-stage disease,
researchers suggest that caution be taken when considering changes in
standard treatment.45
The
literature revealed that fatigue was the most common problem in the
physical domain of HRQOL. The finding that fatigue was more severe for
HD survivors than for healthy controls even years after treatment
completion is consistent with prior research about cancer-related
fatigue. Indeed, fatigue has been reported to occur in approximately 75%
of all cancer patients and can be a more common adverse effect of
treatment than nausea, depression, or pain.46 The high incidence of cancer-related fatigue has led to proposing that it be considered the sixth vital sign.47
Late
medical complications of HD therapy such as cardiac disease and
abnormal thyroid and pulmonary function may contribute to the prevalence
of fatigue in HD survivors compared to other cancer survivors.45
Whether the occurrence of fatigue in cancer survivors is associated
with treatment modality, disease, or nonclinical factors such as
socioeconomic status, age, or gender, patients report that this
assumption profoundly alters their quality of life before and after
treatment.27,36
Increasingly, research findings support the thesis that increased
physical activity ameliorates the incidence of fatigue during and after
treatment and improves physical functioning and other domains of quality
of life.48,49 For example, Oldervoll et al39 reported that fatigue and physical conditioning improved when HD survivors participated in an aerobic exercise program.
Another common physical domain problem is nausea and vomiting. Since the introduction of 5-Hydroxytryptamine3 (5-HT3)
receptor antagonists in 1991, there has been a significant reduction in
posttreatment vomiting, yet treatment-related nausea continues to be a
recurrent and continuing consequence of chemotherapy and is considered
far more difficult to control than treatment-associated emesis. In one
study of HD survivors, 63% experienced persistent anticipatory nausea
and 5% reported anticipatory vomiting, which were thought to be a
response to reminders of treatment, for as long as 6 to 140 months after
completion of chemotherapy. Although these reactions lessened over
time, anticipatory nausea was experienced by half the patients for more
than 2.5 years.50
Promising prevention strategies for the control of anticipatory nausea
and vomiting include both new guidelines for using antiemetics during
treatment and behavioral therapies such as hypnosis.51,52
With
regard to sexuality, the finding that HD survivors reported lowered
motivation for intimacy, along with a decreased interest in sex and loss
of sexual satisfaction, is consistent with findings from other studies
reporting that older adolescents and young adults who experience
distress, depression, and anxiety may experience or show difficulty in
responding to intimacy and lack sexual motivation when stressed.53
Fertility preservation may also be a concern of young adults with HD
and their partners. Issues surrounding fertility and sexuality concerns
should be addressed and evaluated before, during, and after treatment.54
Studies
of the physical domain of HRQOL focused little attention on memory
impairment and cognitive problems although HD survivors often report
difficulties with memory, attention, and new learning after treatment.
The findings of one meta-analysis of specific cognitive effects of
cancer treatment in adults indicated that executive function, verbal
memory, and motor function were negatively affected by systemic cancer
therapies.55
There is some evidence that chemotherapy negatively affects cognitive
ability, sometimes referred to as "chemo brain" or "chemo fog."56,57
Other factors that may influence cognitive decline include stress,
depression, sleep disturbances, fatigue, or the cancer process itself
with the release of toxic by-products (cytokines). Researchers have
begun to report that there is a stimulation of cytokines in breast and
colorectal cancers that may be implicated in deficits of cognitive
function.58
Other researchers have reported survivor complaints of cognitive
problems that can negatively affect daily functioning, vocational
interests, and other aspects of quality of life. Thus, a better
understanding of cognitive function in HD survivors is an important area
for future research.
The
psychological domain of HRQOL continues to be a frequent focus of
research for long-term survivors of cancer. The most common variables
measured in the psychological domain in the studies in this review were
depression and anxiety. The findings revealed mixed results that may be
attributed to a variety of instruments used to measure psychological
distress and the diverse time points for measurement, ranging from
during treatment to many years after treatment completion. Developmental
level at the time a young adult is diagnosed with a serious illness may
have a significant influence on psychological adjustment. For example,
young survivors face the disruption of developmental milestones such as
establishing intimate relationships, fertility, child rearing, and
financial concerns, whereas older adults are looking forward to
retirement.59,60
Survivor responses in the functional and social domains of HRQOL were frequently investigated as well. Seven researchers24,25,27,28,31,41,42
investigated how HD survivors perceived changes in leisure activities,
finances, and employment in response to medical conditions and treatment
effects. Other investigators focused specifically on how fatigue
compromised energy levels and a decline in physical performance that had
a negative impact on work and leisure time.10,29,32,33,35,39,40
Although some researchers have argued that activities not directly
related to health status are outside the purview of the healthcare
provider, such as the measurement of job satisfaction and economic
factors, the impact of treatment on the social/functional domain of
HRQOL for those with cancer or chronic illness is relevant to morbidity,
mortality, and long-term surveillance.61,62
Functional status has not traditionally included measurements of work
satisfaction and the financial consequences of illness, but as
demonstrated in this review, these issues have become increasingly
important to cancer survivors. Advances in early detection and less
debilitating treatments have led to an increased presence of cancer
survivors as active members in the workplace, reinforcing the need to
include this essential component in the measurement of HRQOL.63
Only
2 studies investigating the spirituality domain of HRQOL in HD
survivors were located. Religious and spiritual coping have been shown
to improve other domains of HRQOL in cancer survivors. In a study of 170
patients with advanced cancer, positive religious coping was related to
better existential QOL dimensions, as well as overall QOL.64 Balboni et al65
reported that 72% of respondents with various types of cancer indicated
that they had little opportunity to discuss spiritual concerns with
their healthcare provider. Further studies are needed to understand the
spiritual and religious needs of cancer survivors.66
Theoretical and Methodological Issues
Researchers are encouraged to use existing frameworks for future studies. For example, Wilson and Cleary62
described a theoretical framework that posits causal relationships
among biological and physiological factors, symptoms, functioning,
general health perceptions, and overall quality of life. Ferrans et al67 further developed and revised this model to describe the influences of HRQOL. The Ferrans et al67
model underscores the importance of patient values and preferences and
internal factors such as developmental stage when designing
interventions that are intended to change or modify behavior and improve
HRQOL. Another framework that may be used to guide future research is
the Roy Adaptation Model. This conceptual model depicts individuals as
bio-psychosocial beings who adapt physically, psychologically,
functionally, and socially to ever-changing environmental stimuli.68
Linkages can easily be made between the modes of adaptation and
variables in each domain of HRQOL, as well as between environmental
stimuli and variables such as age, gender, race, education, type of
treatment, and stage of disease.68
The
findings of this review uncovered numerous methodological issues that
need to be resolved, including using more rigorous study designs and
standardizing the measurement of each HRQOL domain. Most studies
reviewed were correlational and cross-sectional; just 4 (11%) of the
studies in this review used longitudinal designs. Murdaugh69
pointed out that HRQOL is a dynamic and nonstatic construct that cannot
accurately reflect the impact of illness at one point in time,
highlighting the need for longitudinal, prospective study designs.
As can be seen in Table 1,
more than 29 different instruments were used to measure the various
domains of HRQOL. Measurement approaches used in the studies included a
single instrument or a battery of different instruments. The 2 most
commonly used single questionnaires measuring HRQOL domains are the
European Organization for Research and Treatment of Cancer Quality of
Life Questionnaire Core 30 and the Medical Outcomes Study Short Form 36 (Table 2).
The European Organization for Research and Treatment of Cancer Quality
of Life Questionnaire Core 30 was used exclusively in European studies
(n = 6) to measure the multidimensional construct of HRQOL. This
instrument is a cancer-specific measure; subscales measure physical,
emotional, cognitive, and social functioning, as well as global health
status.70
Short Form 36, in contrast, is a generic measure that enables
comparison across various diseases. This instrument was used in 7
studies, most of which were conducted in Europe.8,15,26,30,35,39,41
The use of a brief, single, and concise instrument to measure HRQOL
would aid in reducing respondent burden, especially given the high
incidence of fatigue experienced by HD survivors. In addition, the
uniform adoption of a single instrument for measuring HRQOL would allow
for direct comparison of findings across studies and contribute to the
advancement of knowledge.
Researchers
rarely reported categorization of study participants' race, which may
be related to the low incidence of HD in nonwhite persons. Yet in 2005,
HD incidence rates were similar in African American and white,
non-Hispanic populations.71 Only 8 (23%) US studies in this review included descriptions of participant racial/ethnic identity. Zabora et al21
reported that a sample of 680 African American cancer survivors, as
well as those of lower socioeconomic status, experienced greater
distress than did cancer survivors of other races. Addressing HRQOL in
culturally diverse populations cannot be ignored, as evidence suggests
that certain groups may be at risk for decreased HRQOL.
Conclusion
Although
cure rates and survival statistics for patients with HD have improved
dramatically in the last decade, curative treatments have been
implicated in the multiple medical sequelae that occur after treatment,
including second malignancies, cardiac and pulmonary disease, and other
late effects such as infection and endocrine disorders.45
Because HD survivors have had an excellent prognosis for disease-free
survival, this population can be used as a model for investigating the
HRQOL of cancer patients transitioning to survivorship. Implementation
of innovative programs that will improve survivors' adjustment and
gradual return to previous levels of functioning should be a priority.
The results of this systematic review suggest that there is a growing
body of literature that describes the HRQOL problems that occur after
treatment for HD. Gaps in the literature identified through this review
include the lack of longitudinal studies and explicit theoretical
frameworks, inconsistent measurement of HRQOL, and exclusion of minority
groups in study samples. Consensus about standardized HRQOL instruments
would enable researchers to compare findings across studies. As the
evidence related to HRQOL in HD survivors grows, development and testing
of theory-guided interventions are needed to improve the transition
from acute care and enhance the long-term goal of the highest possible
HRQOL.
References and the Originating Source Page- http://www.nursingcenter.com/library/journalarticleprint.asp?Article_ID=940995
1. Lymphoma information network. http://www.lymphomainfo.net/ . Accessed November 2008. [Context Link]
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