Benefits and limitations of health tests offered in community settings

Sep 5 2007

Consumers who queue up for health screenings at the mall, a senior center, a drug store or other retail business could benefit from the information they learn.

But screenings in community settings have limitations. Proponents of community-based screenings say they can be lifesavers, detecting illnesses such as heart disease or diabetes before symptoms are evident. But critics caution that at least some tests aren't specific or sensitive enough to benefit the general public.

The September issue of Mayo Clinic Women's HealthSource covers the benefits and limitations of these health tests commonly offered in community settings:

Blood and blood pressure screenings: Tests to measure cholesterol, blood glucose (to screen for diabetes) and blood pressure are fairly straightforward, pose little risk and can help patients track these important aspects of overall health.

Body fat measurement or simple tests to measure fitness: These tests can help determine overall fitness and provide information indicating where more exercise (and fewer calories) are needed. Such tests are generally risk free and can help patients make healthy lifestyle choices.

Osteoporosis screening: In a community setting, this test typically measures bone density in the heel or wrist bone. It may be useful in assessing the future risk of fractures. An abnormal result indicates the need for more testing, typically a dual energy X-ray absorptiometry (DXA) scan, for more accurate risk predictions.

Vascular ultrasound: Ultrasound technology is used to evaluate blood flow through major arteries and veins. It can provide information about the potential risk of stroke, an abdominal aortic aneurysm or peripheral arterial disease. These test results generally require interpretation by a physician.

Heart scan (coronary calcium scan): This computerized tomography (CT) scan of the heart measures the amount of calcium that may be affecting the heart. Negative results indicate a low risk of heart problems in the next five years. If the results show calcium, the risk of future heart attacks is related to the amount of calcium found.

Full body scan: This test involves taking a CT scan of the entire body. It's promoted as a screening tool for multiple diseases, including heart disease and various types of cancer. Results typically require some degree of interpretation.

With any screening, accuracy is a consideration. Rarely is any screening 100 percent accurate. False-negatives and false-positives are possible. A recent study looking at the cost effectiveness of full body scans found that more than 90 percent of people screened had some type of positive finding indicating a health problem. After further evaluation, only 2 percent had disease.

Community screenings are an excellent way to raise awareness about common diseases and, in some situations, identify disease in its early stages. The benefit is realized when patients take the next step, seeing their physician for diagnosis and treatment.