Technical efficiency and its affecting factors in Tehran's public hospitals: DEA approach and Tobit regression.

Measuring hospital efficiency is one of the tools for determining how to use resources. Considering the necessity of measuring the efficiency in hospitals, the current study was conducted to evaluate the efficiency and its determining factors in the Hospitals affiliated to medical universities in Tehran. This was a descriptive-analytical and longitudinal study. In the first stage of the research, the variables affecting the efficiency of hospitals were extracted using the Delphi method. In the second stage, th. Efficiency of 29 public hospitals in Tehran from 2012 to 2016 was calculated using data envelopment analysis techniques. We performed a sensitivity analysis of the efficiency scores by running the DEA model several times using different combinations of input variables. At last, applying the Tobit regression, factors explaining the inefficiencies of hospitals were determined. Data analysis was done by STATA 12 and SPSS 16 software. Significance level of all the tests was set at .05. In the first stage, 10 input variables and 10 output variables necessary from the mangers' point of view were identified to test efficiency. In the second stage, the mean of hospital efficiency was ascending from 2012 to 2015, and then it descending after 2015. According to the results of sensitivity analysis, despite the variability of technical efficiency during the study period (p<0.0001), the difference between the mean performance scores among different scenarios was not significant (p=0.066). Based on the third stage results, the average length of stay (Beta=-1.60E-12, p=0.030) and educational status (Beta=-2.89E+00, p=0.001) had a significant negative effect on hospitals' efficiency. The study results indicated that the efficiency changes during the years investigated were significant among Tehran public hospitals. The optimal use of inputs to produce hospital services should be on the agenda of health managers and policymakers.