Influencing Factors of Outpatient Medication Costs for Chronic Diseases in China from 2015 to 2018: A Retrospective Study

Background: Chronic diseases have always been a global public health issue. The costs of lifelong chronic disease treatment have resulted in heavy economic burdens to patients and society. The purpose of this study is to explore the influencing factors and current situation of drug expenditures in chronic disease outpatient clinics to provide a reference for alleviating the economic burden and preventing and managing chronic diseases efficiently. Methods: A retrospective analysis of outpatient drug expenditure data for diabetes mellitus, hypertension and coronary heart disease from January 2015 to December 2018 in a tertiary first-class hospital in Chongqing was performed. The data were obtained from outpatient drug cost records. Univariate analysis was used to analyse the differences among the different drug cost groups. Logistic regression was used to explore the influencing factors of outpatient drug costs. Forest plots were used to visualize the results of the influencing factors of drug costs for the different chronic diseases. Results: From 2015 to 2018, there were 190474 diabetes mellitus patients, 129535 hypertension patients, and 21982 coronary heart disease patients. The drug cost per capita for coronary heart disease patients was the highest (687.53 Yuan), followed by diabetes mellitus (582.50 Yuan) and hypertension (473.30 Yuan). The influencing factors included sex (except for hypertension), age, medical payment method, category of major drug, doctor's title, department, and full implementation of the zero mark-up policy. Conclusions: Long-term medication for chronic diseases is expensive; thus, it is necessary to control the cost of medication. The implementation of the zero mark-up policy has effectively controlled drug costs for patients with chronic diseases. The effect of the different medical payment methods on outpatient drug expenses is also obvious. Reducing or controlling high outpatient drug costs is a complex and long-term process that requires multi-sectoral and multi-faceted coordination and cooperation.