Effect of multiple patient reminders in improving diabetic retinopathy screening. A randomized trial

To determine whether multiple mailed patient reminders can produce an increase in the rate of diabetic retinal examinations (DRE) over that seen with a single reminder.

All diabetic members > or = 18 years who were enrolled in a large network-based health maintenance organization (HMO) in California from August 1996 to July 1997 were identified using claims and pharmacy databases. Members who had no record of DRE in the HMO's claims database were then randomized into two groups. Both groups received mailed educational materials and a reminder to obtain the examination. Their physician groups also received a letter explaining the program, current guidelines for DRE, and a list of their diabetes patients with their DRE status. The single intervention group received no additional reminders. The multiple intervention group received additional reminders at 3, 6, and 9 months after baseline if they continued with no record of service, as determined from the claims database.

The study cohort comprised 19,523 diabetic members, which were randomized into single (n = 9,614) and multiple (n = 9,909) intervention groups. There was an increase in monthly DRE rates after the intervention in August 1996 for both intervention groups. After the second reminder was sent to the multiple intervention group, the percentage of diabetic members receiving DRE was higher than the single intervention group. Rates before and after the third intervention were not significantly different, nor were monthly differences found. There was a significant difference in overall annual DRE rates between the groups (P = 0.023).

Multiple patient reminders are more effective than single reminders in improving DRE rates in a managed care setting. However, the improvement noted was clinically small and appeared only after the second reminder; no incremental improvement was seen with additional reminders. Resources used for multiple reminders aimed at diabetic retinopathy might better be spent on other approaches to reducing complications of diabetes.