Immunization registries: costs and savings.

Objectives: The objectives of this study were to quantify the actual costs of developing, maintaining, and operating the Boston Immunization Information System (BIIS), an electronic registry and tracking system, and to compare the registry's costs with those of performing the same functions manually.

Methods: Cost data were obtained from 23 BIIS health care sites, the city health department, and 13 control sites. Actual costs of developing and operating BIIS in 1998 and projected 1999 costs for a hypothetical expanded registry were measured.