Health care utilization in HMO's. Results from two national samples.

HMO's have been endorsed as a means of containing medical care costs. This study is the first use of a national data set to analyze whether HMO's have lower utilization. Regression and logit analyses are used to control for demographic and health status variables. The point estimates confirm that HMO's cut hospital days relative to conventional insurance (e.g., Blue Cross), but imprecision is a serious problem.