Main drivers of diabetes pharmaceuticals expenditures: evidence from OECD countries and Iran.

Purpose: This study aimed to identify the impact of prominent drivers on drug expenditure for diabetes. Method: Following the examination of previous studies, this study identified possible factors contributing to diabetes pharmaceutical expenditures. The explanatory variables for the study were the median population age, access to innovative drugs, GDP per capita, prevalence, price, and consumption of diabetes drugs. Then, to estimate the per capita expenditure among diabetic patients, this study developed the panel data model and two time-series regression models for OECD countries and Iran, respectively. Results: In the panel data regression model, R2 was 0.43. The influence of the age, prevalence, consumption volume and GDP per capita coefficients were + 1.79, + 0.704, + 3.86057, + 0.00054, respectively. Also, the probability level of all variables was less than 0.05. In Iran's comparative time-series regression model, R2 was 0.9, and the only significant influence coefficient was the age (β=+0.91). In the another model for Iran, R2 was 0.99, the influence coefficient of age was + 0.249, the prevalence was + 0.131, innovation was + 0.029, and the price was + 0.00054; all the probability levels were less than 0.05. Conclusion: Pharmaceutical per capita expenditure is affected by several factors. These factors are not the same in various counties. Passing a judgment on drug utilization only based on pharmaceutical per capita expenditure cannot be perfect. Also, judging whether the per capita drug expenditure in one country is desirable without attention to the affecting factors and only relying on the value of utilized medicines is defective.