Guideline-Based Screening May Miss Up to Half of Diabetic and Prediabetic Patients

A retrospective analysis of diabetes and prediabetes diagnoses found that screening guidelines from the United States Preventative Service Task Force (USPSTF) would have detected less than half of all cases that were discovered.

The USPSTF guidelines, which were introduced last fall, recommend that all patients aged 40-70 years whose body mass index (BMI) is ≥ 25 be screened for dysglycemia (ie, either type 2 diabetes mellitus [T2DM] or prediabetes). Investigators checked how these screening recommendations would have fared on 50,515 primary care patients from 6 health centers in the Midwest and Southwest.

Electronic health record (EHR) data from 2008 to 2010 indicated that, at baseline, 12,679 (25.1%) met USPSTF guidelines for automatic screening and that 8,478 of the total cohort was actually diagnosed with either T2DM (2,518 patients) or prediabetes (5,960 patients) during an average of 1.6 years of follow-up.

Investigators from Northwestern University compared the pool of patients who qualified for screening with the pool of patients who were diagnosed with T2DM or prediabetes. Overall, they found, only 45% of those who were eventually diagnosed with dysglycemia would have been urged to undergo screening under current USPSTF testing criteria.

When they separated the total cohort by race, investigators found that 54.5% of dysglycemic white patients (95% confidence interval [CI], 52.0%-57.1%) 50.3% of dysglycemic black patients (95% CI, 48.4%-52.1%) and 37.7% (95% CI, 36.1%-39.2%) dysglycemic Latino patients would have been advised to undergo screening.

Investigators then looked why dysglycemic patients did not meet the USPSTF’s screening guidelines and found that 77.7% of them were under the age of 40 and 29.3% of them had BMIs under 25.

The tendency to develop T2DM or prediabetes before reaching 40 years of age was even greater among black and (especially) Latino patients than it was among white patients, which is the main reason why the current guidelines performed worse among minorities in the sample population than they did among white patients, said study senior author Matthew O'Brien, MD, who noted the potential dangers of the guidelines’ shortcomings.

"Preventing and treating diabetes early is very important, especially in this setting of community health centers, where many of their socioeconomically disadvantaged patients face barriers to following up regularly,” said O’Brien, and assistant professor of medicine at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. “If you miss someone now, it might be years before they come back, at which point they have overt diabetes and maybe even complications, like heart attacks or strokes.”

Overall, 29,946 patients (59.3%) — including 77.8% of those who would have been recommended for screening under current USPSTF guidelines and 53.1% of those who would not — wound up undergoing screening within 3 years of their baseline visits. Screening detected T2DM or prediabetes in 38.8% of those who met current guidelines and 23.2% of those who did not.

Still, the majority of detected dysglycemia was detected in the second patient group, and the authors of the new study worry that the new USPSTF guidelines reduce the chance that such patients will be screened in future.

“While diabetes screening occurred in approximately half of the patients who would not be eligible according to the 2015 USPSTF recommendation, this practice may change after implementation of the new screening criteria,” the study authors wrote in PLOS Medicine .

Previous studies have reported good adherence to other USPSTF screening recommendations, which suggests that dysglycemia screening may occur less frequently among ineligible patients in the future. The lack of mandated insurance coverage for screening among ineligible patients in the US may also result in lower screening rates than those observed here.”