If you’ve ever compared notes with another person who has diabetes, chances are that your treatment regimens are different, even if you have the same type of diabetes. Why is this?
Health-care practitioners have a large amount of information to take into consideration when deciding on a course of therapy for an individual. They have information on the condition itself and what causes it. They have information on the options for treating it, and, for some conditions, there may be many options. And they have information on the person needing treatment, which can also affect which type of therapy is offered.
This article explores how doctors decide what therapy to recommend and why finding the best therapy for any one individual often takes trial and error.
Diagnosing the problem
The condition or symptom to be treated is the basis for choosing a treatment. Sometimes a diagnosis is made when a person comes to his doctor with symptoms, and sometimes a routine screening test reveals a medical condition needing treatment, even when there are no symptoms. In the case of diabetes, a diagnosis may be made based on a combination of symptoms of diabetes — such as excessive thirst, frequently passing large volumes of urine, and weight loss — and a blood test, or it may be made based on the results of a blood test alone, even when a person has no symptoms.
Years of research go into determining which tests to use to diagnose a condition, as well as which test results indicate that treatment is needed. In some cases, a test must be repeated one or more times to confirm the first result, or another test must be done to confirm a diagnosis.
However, both the test used to diagnose a condition, and/or the test result at which a diagnosis is made, may change over time, as more research is done, more is learned about a condition, and better tests are devised.
The are currently four types of blood tests that can be used to diagnose diabetes: the HbA1c test (a result of 6.5% or higher means diabetes), the fasting plasma glucose test (a result of 126 mg/dl or higher means diabetes), the oral glucose tolerance test (a two-hour plasma glucose level of 200 mg/dl or higher means diabetes), and the random plasma glucose test (a level of 200 mg/dl or higher means diabetes in a person with symptoms of diabetes). In each case, the practitioner must choose the most appropriate test.
Up until recently, the fasting plasma glucose test was the preferred test for screening people for Type 2 diabetes. In 2010, however, the American Diabetes Association (ADA) began recommending that the HbA1c test be used instead. This is at least in part because it is not necessary to fast before having an HbA1c test, the test does not require drinking a glucose solution, and a person’s HbA1c level is unaffected by stress or illness at the time the blood sample is taken. However, one of the other tests may still be used if a practitioner has reason to believe that one of them would give more meaningful results in a given individual. And when screening pregnant women for gestational diabetes, the oral glucose tolerance test is still the preferred test, but the cut-off values indicating gestational diabetes are different from the cut-off indicating Type 1 or Type 2 diabetes.
There are multiple ways to diagnose many conditions other than diabetes, as well, and the test chosen often depends on the individual. This is because personal characteristics such as sex or the presence of certain medical conditions can affect the accuracy of some medical tests. Being a woman and having diabetes, for example, can influence which tests are used to detect coronary artery disease.