Patterns of service use and costs in model day hospital-in programs in Boston and Tucson.

Patterns of service use and costs in two similar model day hospital-inn programs for psychiatric patients in publicly funded hospitals in Boston and Tucson are compared. Implementation of the programs resulted in cost savings at both sites, although mean annual costs per patient were much lower in Tucson than in Boston. Compared with patients at the Boston site, patients in Tucson had more admissions but shorter stays and fewer days in the program during a 12-month follow-up period. Site-specific differences in the programs, in local practice patterns, and in state mental health funding levels may have influenced cost differences.