RESUMO
Background: Global payment system is a kind of case-based payment system which pays for 60 commonly surgical operations by the average cost for each specified surgery case in Iran. The aim of the study was to determine the effect of this payment system on the number of services provided for each global surgical case versus fee-for-service (FFS) for the same operation. Methods: This is a retrospective study based on data from a large referral teaching hospital in Iran in the period of 2012-2015. Information related to 46 surgeries was performed which both global and FFS documents were gathered (N=7672). Statistical analysis was done on variables including Length of stay (LOS), Blood test (BT), Radiology (RA) and a mixed variable named VC (visit and consult number). Data were analyzed by a zero-inflated negative binomial regression model using STATA 11. Results: Descriptive analysis showed the mean of each service was significantly (p<0.001) higher in the FFS document's group rather than the global payment group. Regression estimates showed the amounts of each service including LOS, BT, RA and VC were significantly (p<0.001) higher in FFS surgery than global documents for the 15 selected surgery. LOS and BT have shown a significantly higher amount in 100% of surgeries for FFS above global document. Same as for Radiology test and VC variables, there were significantly higher amounts in 93% of surgeries for FFS above global hospital documents. Conclusion: The findings can reinforce the presence of a relationship between providing more clinical services in FFS document form and providers' incentives to adjust profits against their Costs. The significantly higher service provision in FFS documents can be controlled with a prospective global payment mechanism.