Impact of appointment reminders on vaccination coverage at an urban clinic.

OBJECTIVE To test if appointment reminders blinded to immunization status improve kept-appointment and vaccination coverage rates. Design. Controlled trial. SETTING Pediatric clinic serving a low-income community in New York City. INTERVENTION Children ages 4 through 18 months (n = 1273) scheduled sequentially for clinic appointments were systematically assigned to 1 of 4 study groups: control (n = 346); postcard (n = 314); telephone call (n = 307); and postcard and telephone call (n = 306). OUTCOME MEASURES Kept-appointment and vaccination coverage rates. RESULTS Children assigned to the postcard and telephone group were 1.75 times more likely to keep their appointments than controls (95% confidence interval [CI] = 1.2, 2.5). Children who actually received the postcard and telephone reminders were 2.3 times more likely to keep an appointment than controls (95% CI = 1.4, 3.7). Children who kept appointments were 2.3 times more likely to be up-to-date with their immunizations (95% CI = 1.7, 3.2). The reminders selectively increased vaccination coverage for the subgroup of children who were not up-to-date before the appointment (chi(2) = 11.2). The cost of the reminders was $.67 for the postcard and $1.58 for the postcard and telephone. Assuming 5000 visits per year and $100 reimbursement per visit, the return on each dollar invested was $10 for the postcard and $7.28 for the postcard and telephone reminder. CONCLUSIONS Appointment reminders blind to immunization status are a practical and cost-effective strategy to increase kept-appointment rates for all children, and, through this mechanism, reach and vaccinate children who are not up-to-date.appointment reminder, vaccination coverage.