The impact of the National Health Insurance Scheme on medication adherence of hypertensive patients

Background: There is paucity of information on the effectiveness of the National Health Insurance Scheme (NHIS) in improving medication access in hypertensive patients, as well as its impact on adherence rates and patient outcomes.

Objectives: This study investigated the impact of NHIS enrollment on medication adherence in hypertensive patients by assessing disparities in adherence profiles and patterns of barriers to medication adherence between enrolled and non-enrolled patients of the NHIS, and evaluating the extent to which cost of medication affects adherence.

Methods: The study was conducted as a cross-sectional prospective study. Medication adherence score was determined using the eight-item Morisky Medication Adherence Scale, which was self-administered to 250 selected patients on NHIS and non-NHIS respectively. Data was analyzed using SPSS 16 for Windows (Chicago, IL); Mean ± standard deviation was computed for continuous data, Mean values were compared using t-test while comparisons of proportions were carried out using Chi square. All hypotheses tested were two tailed, with significance at p < 0.05.

Results: The mean adherence score for the NHIS group was 4.40 ± 2.28, while respondents in the non-NHIS grouprecorded a mean adherence score of 4.92 ± 2.15. The non-NHIS group reported a statistically significant higher adherence score (p= 0.011). From the multiple linear regressions, there was a positive correlation between adherence score and age and duration of disease. There was also statistically significant negative correlation between adherence scores and educational level, monthly income, and improving health status.

Conclusion: Enrollment in the NHIS was not associated with better medication adherence level despite associated lower cost of medication. Cost of medication was not found to be a statistically significant barrier to adherence in this study.