Interventions to improve medication adherence in chronic disease: A narrative review of what works in pharmacy practice

Background: Medication non-adherence in chronic diseases is associated with increased morbidity, mortality, hospital admissions, and healthcare costs. Community pharmacists are frequently positioned to deliver adherence interventions, yet the evidence base lacks clear guidance on which strategies work best in routine practice. Objective: This narrative review synthesizes evidence on pharmacy-based interventions to improve medication adherence in chronic disease and examines the quality of evidence for different intervention types. Methods: A PubMed search (2015–2025) identified systematic reviews, randomized controlled trials, and clinical trials of pharmacist-led interventions targeting adherence in hypertension, diabetes, asthma, COPD, and hyperlipidemia. A total of 112 articles were screened, of which 28 full-text articles were assessed for eligibility. Eighteen studies met inclusion criteria and were categorized as educational, digital, behavioral, financial, or multi-component based on intervention type. Results: Across 18 included studies, educational interventions consistently improved medication adherence, particularly when trust-based. Digital tools like SMS and digital inhalers showed positive effects across multiple conditions. Financial strategies (subsidies, home delivery) benefited low-income populations. Multi-component interventions demonstrated the strongest effects but required careful implementation. However, workforce related constraints, local barriers, and health system limitations frequently hindered real-world application.. Evidence quality varied, with only 4 of 18 studies (22%) reporting implementation outcomes or theory-driven design. Conclusion: Community pharmacists have several evidence-based strategies to improve medication adherence. Multi-component approaches appear most effective. However, most studies focus on efficacy under ideal conditions rather than effectiveness in routine practice. Future research should prioritize implementation science to adapt interventions to local contexts, address workforce constraints, and report theory-driven designs, especially in LMICs. Journals and reviewers should require clearer reporting of implementation barriers and target population specifications.