Hospital cost and efficiency under per service and per case payment in Maryland: a tale of the carrot and the stick.

The simultaneous operation of per case and per service payment systems in Maryland, and the varying levels of stringency used in setting per case rates, allows a comparison of the effects of differing incentive structures on hospital costs. This paper presents such a comparison with 1977-1981 data. Regressions performed on cost-per-case and total cost data indicate that costs were lower only when per case payment limits were very stringent. Positive net revenue incentives appeared to be insufficient to induce a reduction in length of stay or ancillary services use. These changes in medical practice patterns thus appear more likely under the threat of financial losses--that is, under the threat of the stick rather than the inducement of the carrot.