COMPUTER-GENERATED RECALL LETTERS FOR UNDERIMMUNIZED CHILDREN - HOW COST-EFFECTIVE

Objective. To evaluate the effectiveness and cost effectiveness of com puter-generated recall letters to parents of children overdue for immu nizations. Methods. This randomized controlled trial included children of two facilities in a regional health maintenance organization. Pare nts of 20-month-olds who had not yet received a measles-mumps-rubella (MMR) immunization were identified via a computerized immunization tra cking system. One half were mailed personalized letters that included the recommended immunization schedule and a request to call for an app ointment; the other half served as a control group. Receipt of the MMR between 28 and 24 months of age was evaluated with the computerized t racking system, a telephone survey was conducted with parents whose ch ildren had not received the MMR by 24 months. Decision analysis was us ed to project the theoretical outcomes and costs of a recall letter po licy for other populations. Results. Among 20-month-old children 10% h ad not received the MMR; 289 families were included in the analysis. O f families who were mailed letters, 54% (82 of 153) received the MMR b y 24 months of age, compared with 35% (47 of 136) of those in the cont rol group (P = 0.001). The telephone survey was completed with 110 par ents of children who still did not appear on the health plan computer as having received the MMR by 24 months. Fifteen percent said the chil d had received an immunization at an outside provider and of the rest 62% said they had not been aware that an immunization was due. In the cost effectiveness analysis it was project;ed that recall letters woul d increase the immunization rate for the regional population of approx imately 30 000 children from 86% to 90% at a total cost of $5031 annua lly. The cost per additional child appropriately immunized was $4.04. In sensitivity analyses this cost effectiveness ratio varied depending on the baseline population coverage rate as well as the estimated eff ectiveness of recall letters. Conclusions. Computer-generated letters to recall children overdue for immunizations resulted in a higher prop ortion of children appropriately immunized in this setting. However, t he strategy was not as cost-effective as intuition might suggest. Furt her studies in health maintenance organization (HMO) settings should c ompare the cost effectiveness of letters with other low cost strategie s including automated telephone reminders.