Factors influencing antihypertensive medication compliance in Taiwan: a nationwide population-based study.
BACKGROUND
Poor medication compliance with antihypertensive drugs may have a significant impact on clinical outcomes, hospitalisation and healthcare expenditure. This study aims to assess medication compliance and its underlying factors in patients receiving antihypertensive drugs in Taiwan.


METHODS
This retrospective population-based study was based on data from Taiwan's Longitudinal Health Insurance Database (LHID). All patients (n = 78,558) were aged 30 years or more and had received at least one antihypertensive prescription between January 2004 and December 2007. We used the medication possession ratio (MPR) as an index to measure the level of medication compliance.


RESULTS
Approximately 53% of the patients had high compliance with antihypertensive medication. Factors that were positively associated with medication compliance included patients being aged 30-44 years, higher comorbidity scores (odds ratio (OR): 1.18; 95% confidence interval (CI): 1.08-1.28), the same prescribing physician being visited and a single-drug therapy being prescribed. Female sex (OR: 0.92; 95% CI: 0.89-0.95) and higher socioeconomic status (OR: 0.91; 95% CI: 0.86-0.96) were negatively associated with drug compliance. In addition, high-compliance patients were less likely to be treated at medical centres, corporations (OR: 0.89; 95% CI: 0.84-0.93) or rural (OR: 0.88; 95% CI: 0.83-0.94) institutions.


CONCLUSIONS
Several patient- and institution-related factors may influence medication compliance. Therefore, for optimal outcomes, patients' awareness of the need for compliance with antihypertensive therapy must be enhanced, and effective intervention strategies should be developed.
Institute of Medicine, Chung Shan Medical University, Taiwan.
Chien-Ying
CY
Lee
Chun-Che
CC
Huang
Hung-Che
HC
Shih
Kuang-Hua
KH
Huang
D000328:Adult; D000367:Age Factors; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D004359:Drug Therapy, Combination; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D009819:Office Visits; D012189:Retrospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors; D013624:Taiwan; D013997:Time Factors; D016896:Treatment Outcome
D000959:Antihypertensive Agents