Effectiveness of Telemedicine-Based Interventions in Primary Health Care: A Systematic Review in a Universal Health System

INTRODUCTION: Telemedicine has increasingly been adopted as a digital care strategy to support access, continuity, and care coordination in primary health care (PHC). While its use accelerated during the COVID-19 pandemic, evidence regarding the effectiveness of telemedicine-based interventions in routine primary care remains heterogeneous and highly context-dependent. The objective of this review was to critically assess the effectiveness of telemedicine-based interventions in PHC, focusing on their effects on access, continuity, and care coordination, and to identify implementation-related barriers and facilitators based on empirical evidence from a universal health system context. METHODS: A systematic review was conducted in accordance with PRISMA 2020 and registered in PROSPERO (CRD420251005446). Searches were performed in PubMed/MEDLINE, SciELO, and BVS/LILACS for studies published between 2015 and 2025. Two reviewers independently screened studies and extracted data. Risk of bias was assessed using RoB 2.0 and ROBINS-I. Due to methodological heterogeneity, findings were synthesized through a structured narrative approach (SWiM), and certainty of evidence was interpreted qualitatively based on study design, risk of bias, and consistency of findings. RESULTS: Twenty-two studies were included, evaluating teleconsultations, telemonitoring, telediagnosis, tele-regulation, and tele-education in PHC settings. Telemedicine-based interventions were associated with improved access, reduced waiting times, and enhanced care coordination, particularly when embedded within primary care teams and integrated with information systems. Telemonitoring showed more consistent benefits for chronic disease management and continuity of care. User and provider acceptability was generally high, although technical limitations, workload concerns, and digital inequities were frequently reported. Certainty of evidence ranged from low to moderate. CONCLUSIONS: Telemedicine-based interventions can strengthen core PHC functions when implemented as integrated organizational components of routine care delivery rather than as standalone technologies. Their effectiveness is strongly shaped by implementation context, digital infrastructure, and workforce readiness, highlighting the need for pragmatic and implementation-focused evaluations to inform sustainable telemedicine integration in primary care systems.