Decomposing the effect of drug benefit program on antihypertensive medication adherence among the elderly in urban China

Abstract

Purpose

Hypertension is a rapidly growing epidemic in People’s Republic of China, yet it remains inadequately controlled. This study aimed to identify the relative contributions of program effects and patients’ characteristics to the differences in antihypertensive medication nonadherence between drug benefit program enrollees and non-enrollees.

Patients and methods

Data were from a cross-sectional survey of 1,969 community-dwelling elderly adults with hypertension. Self-reported adherence was measured following previous studies in People’s Republic of China. The Blinder-Oaxaca nonlinear decomposition method was used to identify the relative contributions of program effects and patients’ individual characteristics.

Results

Eleven percent of the drug benefit program enrollees were nonadherent to their medication, while 17% of non-enrollees were. Blinder-Oaxaca decomposition identified that over 60% of the gap between the two groups was due to the program effects (P=0.024). The rest could be explained by differences in observable characteristics (P<0.001), such as diabetic status, duration of hypertension, and blood pressure control.

Conclusion

The study confirmed that drug benefit program enrollees were more likely to be adherent to their antihypertensive medication than non-enrollees in the context of People’s Republic of China.

Keywords:

• medication adherence
• drug benefit program
• decomposition
• hypertension

Acknowledgments

We sincerely acknowledge those patients who participated in the survey. We are grateful to Lu Mao, Yinxia Zheng, Wangfei Cui, Yanli He, Yan Huang, and all college students who participated in our survey for data collection. We would like to thank Rujiang Liang for STATA programming. We would also like to thank the Department of Public Health, Shihezi University School of Medicine, for providing assistance.

Disclosure

The authors report no conflicts of interest in this work.

Supplemenatary materials

Table S1 Logistic regression analysis between drug benefit program enrollees and non-enrollees

Table S2 Contribution of drug benefit program effect to the differences in medication nonadherence between drug benefit program enrollees and non-enrollees

Table S3 Contribution of observed characteristics to the differences in medication nonadherence between drug benefit program enrollees and non-enrollees