The Impact of China's National Essential Medicine Policy and Its Implications for Urban Outpatients: A Multivariate Difference-in-Differences Study.

OBJECTIVES: To evaluate the effects of the National Essential Medicine Policy (NEMP) on outpatient service utilization and expenditure in Tianjin, China.

METHODS: All government-owned general primary health care centers (PHCs) within the Urban Employee Basic Medical Insurance in Tianjin were involved in the study. Of these, 49 PHCs implemented the NEMP in April 2009, and constituted the intervention group, and the remaining PHCs constituted the control group. Patients who had visited only one of the two groups at least once pre-NEMP (April 2008 to March 2009) and post-NEMP (April 2009 to March 2010) were included in the correspondent group. A difference-in-differences (DID) analysis was used to estimate the impacts adjusting for patients' sociodemographic characteristics and health status. Sensitivity was tested using the propensity score matching method.

RESULTS: A total of 23,362 and 4,148 patients from the intervention and control groups were identified, respectively. The patients in the intervention group were older (63.7 years vs. 58.8 years; P < 0.001) and in worse health status, as indicated by the Quan-Charlson comorbidity index (1.0 vs. 0.7; P < 0.001), than their counterparts in the control group. The DID results controlling for other confounders indicated that the annual outpatient visits, total annual expenditure, drug expenditure, and out-of-pocket expenditure per capita for the intervention group were not significantly different from those of the control group. Propensity score matching-adjusted DID regression models demonstrated similar results.

CONCLUSIONS: The China NEMP implementation did not affect the annual outpatient visits, total expenditure, drug expenditure, and out-of-pocket expenditure in the short term and the original policy goals were not met.