Study objectives: To assess whether the introduction of "managed care" (capitated budget and utilisation control by general practitioners) in a Swiss health insurance plan caused a selective disenrolment of plan members, and whether it achieved its goal of reducing health care expenditures.
Design: Controlled before-after analysis of health insurance claims.
Setting: Health insurance plan of the University of Geneva, Switzerland, which introduced managed care at the end of 1992, and comparison plan, which reimbursed health care expenditures without setting a budget or controlling access.
Participants: Analysis of self selection: university plan members who accepted (3993) or refused (659) transfer to managed care. Analysis of change in expenditures: cohorts of persons continuously enrolled in the university (1575) and comparison (3384) plans in 1992 and 1993.
Main results: During 1992, the year before the transformation of the university plan, persons who refused managed care had generated 35% higher expenditures than those who accepted managed care (p < 0.001). Between 1992 and 1993, expenditures per member decreased by 9% in the university cohort and increased by 11% in the comparison cohort (p = 0.004). Technical procedures (laboratory tests, physical therapy, drugs) decreased most in the university plan. No impact on hospital admissions was detected.
Conclusions: Introduction of gatekeeping and budget management by physicians caused a favourable self selection process for the university plan. In addition, the managed care plan achieved a substantial decrease in overall health care expenditures in its first year of operation, chiefly by reducing outlays for technical procedures.