HMO growth and hospital expenses and use: a simultaneous-equation approach.

摘要: A principal problem with previous studies that have estimated the effects of prepaid group practices (PGPs) on hospital costs and use is treatment PGP growth rates as an exogenous variable. To extent entry subsequent PGPs may be affected by high low use, observed association between market shares confounded. separate expenses from growth, a simultaneous-equation model using data for 25 standard metropolitan statistical areas (SMSAs) 1972 to 1982. The results indicate has significant positive effect average per day admission in SMSA, but no statistically capita. also negative both length stay. In contrast single-equation specifications, neither higher nor are found result levels SMSA and, fact, lower capita lead significantly share levels.