The best primary care-based research comes out of Europe, where countries have medical research budgets that actually fund primary care research. The U.S. has no equivalent funder. Therefore, American family physicians must often look overseas for answers to their daily clinical questions.
Does screening for diabetes make any difference? A recent study funded by the Medical Research Council of Britain aimed to find out. Researchers conducted a pragmatic cluster-randomized controlled trial of diabetes screening including nearly 19,000 people aged 40 to 69 at high risk of diabetes who were recruited in GP practices in eastern England. Some practices were randomized to screen for diabetes. The others did not.
The bottom line results were as you might expect. There were no differences after 7 years between the screened and control groups for heart attacks, strokes, broader measures of physical health and quality of life, smoking status, or alcohol consumption. For the latter outcomes, the point is that learning that you had diabetes and/or being screened for it did not seem to cause those people to measurably change their lifestyles.
This study made me think of another study documenting peoples‘s beliefs about the value of screening tests. They systematically reviewed the literature that asked general populations about their beliefs about the benefits and harms of screening treatments for diseases that were detected. Most studies only asked about benefits and didn’t even bring up the possibility of harms. 54 outcomes were assessed and subjects overestimated the benefits in 65% of studies that reported numerical results, and 88% of studies that just had a subjective report. Expectations of harm were underestimated in the majority of studies.
The USPSTF has talked about broadening its recommendations for screening for diabetes. For now, I believe it only recommends it for patients with hypertension. It will be interested to see if and how this well-done large study influences their deliberations.