Screening for diabetes may not reduce mortality

One round of screening for type 2 diabetes in high-risk patients was not associated with a reduction in all-cause, cardiovascular, or diabetes-related mortality within 10 years, researchers in the U.K. reported.

Researchers conducted a pragmatic parallel group, cluster-randomized trial that recruited more than 20,000 people age 40 to 69 on the basis of a previously validated risk score from among 33 general practices in England. Practices were randomly assigned to three groups: 15 practices conducting screening followed by intensive treatment for diabetics, 13 practices conducting screening plus routine care of diabetes according to national guidelines, and five practices that did not screen and acted as a control group.

Results appeared Oct. 4 in The Lancet.

During more than 184,000 person-years of follow-up, there were 1,532 deaths in the screening practices and 377 in control practices (mortality hazard ratio [HR], 1.06; 95% CI, 0.90 to 1.25). Results were analyzed by intention-to-screen (73% of screening group were screened). There was no significant reduction in mortality from cardiovascular causes (HR, 1.02; 95% CI, 0.75 to 1.38), cancer (HR, 1.08; 95% CI, 0.90 to 1.30), or diabetes (HR, 1.26, 95% CI, 0.75 to 2.10) associated with invitation to screening.

The benefits of screening were smaller than found in modeling studies. The authors noted, however, that the mortality rates found in their study were also lower than expected. They concluded that screening might be beneficial only to individuals with detectable disease, rather than the population as a whole.

“If population-based screening for diabetes is to be implemented, it should be undertaken alongside assessment and management of risk factors for diabetes and cardiovascular disease and population level preventive strategies targeting underlying determinants of these diseases,” researchers wrote.