Data-Driven Patient Engagement to Improve Medication Adherence: A Narrative Review of Targeted Outreach Across Health...

Medication nonadherence undermines chronic disease control and generates avoidable morbidity, mortality, and costs. Between 2010 and 2020, globally, approximately 27% to 40% of patients prescribed antihypertensive therapy were not adherent; poor adherence was associated with 38% higher hospitalization and mortality risks, while similar patterns held for diabetes and lipid-lowering medicines. This narrative review synthesizes evidence on targeted, data-driven outreach interventions to improve medication adherence. MEDLINE/PubMed, Scopus, and Web of Science were searched for English-language studies (2000-2025, with emphasis on 2019-2025) involving adults or adolescents with measured adherence outcomes (proportion of days covered (PDC), medication possession ratio (MPR), or persistence). Priority was given to randomized trials, economic evaluations, and implementation reports. Interventions varied from low-cost SMS or interactive voice responses to app-based platforms, clinics led by pharmacists, and appointment-based models or medication synchronization (ABM). We identified strategies that reliably improved the PDC or MPR, assessed feasibility across settings, and highlighted equity, privacy, and sustainability considerations. Risk-stratification models demonstrated moderate predictive performance; two-way messaging and pharmacist integration provided consistent benefits that depended on the context, while one-way reminders produced varied effects. Cost‑effectiveness was generally favorable for digital outreach but underreported in low‑ and middle‑income countries. Fairness audits, governance safeguards, and ethical data use remain essential.