Non-adherence to anti-hypertensive medications in a low-resource country Nepal: a systematic review and meta-analysis

Background: Nepal is a low resource country with cardiovascular diseases being the number one cause of mortality. Despite hypertension being the single most important risk factor for cardiovascular diseases, non-adherence to anti-hypertensive medications has not been assessed systematically. So, this systematic review and meta-analysis aims to analyze the prevalence of non-adherence to anti-hypertensive medications in Nepal. Methodology: This systematic review and meta-analysis was piloted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Electronic databases of Embase, PubMed, Scopus, Web of Science, Cochrane Library, Cinhal Plus, and Google Scholar were searched from inception till 1 February 2023. The random-effects model with 95% confidence interval (CI) was used to calculate the non-adherence rate. Results: Altogether, 14 studies with a total of 3276 hypertensive patients were included in the meta-analysis. The pooled prevalence of non-adherence to anti-hypertensive medications was 49% (95% CI: 0.37-0.62, I2 = 98.41%, P < 0.001). The nonadherence rate using Morisky Medication Adherence Scale (MMAS) was 55% (95% CI: 0.34-0.76, I-2 = 99.14%, P < 0.001), and using Hill-Bone Compliance Scale, the non-adherence rate was 45% (95% CI: 0.37-0.54, I-2 = 84.36%, P < 0.001). In subgroup analysis, the non-adherence was higher in rural areas 56% (95% CI: 0.51-0.61, I-2 = 0.0%, P = 0.46) compared to urban areas 42% (95% CI: 0.31-0.54, I-2 = 96.90%, P < 0.001). The trend of non-adherence was increasing after 2020. Additionally, forgetfulness, carelessness, cost of medications, number of comorbidities, and using an alternate form of medication were common factors associated with non-adherence. Conclusions: This meta-analysis showed that half of the hypertensive population of Nepal are non-adherent to their anti hypertensive medications, thereby posing a significant long-term cardiovascular consequence among Nepali population.