DESIGN ISSUES FOR A BIG CITY IMMUNIZATION REGISTRY

New York is the nation's largest city with a birth cohort of more than 130,000 and nearly 2 million children aged 18 years and under. Its sh eer size has important implications for registry design, as do the pov erty, cultural diversity, and mobility of the population, as well as l arge numbers of special groups, such as homeless people and recent imm igrants. The size and diversity of the provider population also have c onsequences for immunization registry planning. The private sector is heavily represented-about 55% of the immunizations are given by physic ians in private practice, voluntary hospitals, and private clinics. Pu blic and private providers practice in a variety of settings and span all levels of technologic sophistication. This article addresses the w ays in which New York City's technical registry design and implementat ion plan have responded to local requirements and constraints. Topics covered include decisions about roles and responsibilities of central registry reporting and retrieving information, child identifiers colle cted and match strategies, and policy decisions about security and con fidentiality. It is instructive to examine the process and rationale f or New York City's design decisions, as well as the decisions themselv es. Some of the decisions may in fact be generalizable to other large systems; some of the rejected alternatives may be appropriate under a different set of constraints. The entire decision process demonstrates how a group of planners took a general concept (an immunization regis try) and modified it in the course of bringing it to the threshold of implementation, in the summer of 1996.