Direct mail intervention to increase retinal examination rates in Medicare beneficiaries with diabetes

The objective of this study was to identify the baseline frequency of eye examinations for Medicare beneficiaries with diabetes in Montana and to determine whether a direct mail reminder increased eye examinations. Using Medicare Part A and Medicare Part B claims data, a cohort of Medicare beneficiaries with diabetes was defined. Eye examination claims were identified using billing codes specific for retinal examinations, as well as visits to ophthalmologists and optometrists during which retinal exams were likely to have been performed. A random sample of the identified beneficiaries with diabetes received a letter encouraging regular annual retinal examinations. In the first 3-month period after the mailing, the billed eye examination rate for those to whom letters were sent was 2.2 percentage points greater than the rate for those to whom letters were not sent (19.4% vs 17.2%; relative risk, 1.13; 95% confidence interval, 1.01-1.26). However, 6 months after the letters were sent, there was no longer a significant difference in the rates for these 2 groups (32.9% vs 32.4%; relative risk, 1.02; 95% confidence interval, 0.94-1.10). In this study, direct mail outreach initially influenced the proportion of Medicare beneficiaries receiving an eye examination, but this pattern was not sustained over the 6-month follow-up period.