Computer reminders improve on-time immunization rates.

Objectives: This study examines the effectiveness of computer-generated telephone reminders in improving infants receiving on-time immunizations. A computer called parents at home, reminded them of their child's visit, and asked if they could keep the appointment. If parents either canceled or failed to honor the appointment, the computer called back a few days later and asked them to reschedule.

Methods: A medical assistant recruited 124 consecutive mothers to receive automated computer reminders. These mothers' infants were younger than 6 months, were being seen at an outpatient clinic for a first visit, and were patients of three attending physicians and three nurse practitioners. These infants were compared to 89 infants from the same clinic, in the same age range, who were being seen for the first time during the same period by the same providers but not contacted by the medical assistant. Subjects were selected from mothers who brought their infants for their first visit in an outpatient urban clinic that serves predominantly minority clients. A research assistant reviewed patients' medical records and collected the infants' birthday, mothers' age, race, source of payments, and the immunization record of the infants. Immunization was considered to be late if, at the time of the first visit, it was more than 30 days past due for any of the recommended immunizations of the American Academy of Pediatrics, except for Hepatitis B vaccine which was not recommended at the time of the study. The dependent variable was on-time immunization. The independent variables were age of the mother at baseline, age of the child at baseline, and membership in either the comparison or the experimental group. Chi-square tests and logistic regression were used to analyze the data.

Results: The participation rate for appointments for the experimental group was 82%, as compared to a 69% overall participation rate for the clinic providers. The on-time immunization rate for experimental subjects was 67.8%, whereas the comparison group had an on-time immunization rate of 43.4% (differences were significant at alpha levels less than 0.01).

Conclusions: Computerized reminders sent to the parents led to an increase in participation rate at the clinic and an increase in on-time immunization for their infants.