Impact of Patient Portals on Asthma and Chronic Obstructive Pulmonary Disease-Related Quality-of-Care Outcomes: Systematic Review.

BACKGROUND: Patient portals are increasingly used to support self-management and facilitate care coordination in people with chronic diseases. Although some asthma quality-of-care gains and modest chronic obstructive pulmonary disease (COPD) improvements have been reported in wider digital health studies, a comprehensive review of patient portal-specific evidence is lacking. OBJECTIVE: This study aimed to systematically synthesize evidence on the impacts of patient portals on adult asthma and COPD outcomes across 6 quality-of-care domains (effectiveness, patient-centeredness, equity, efficiency, safety, and timeliness). METHODS: We searched 5 databases (MEDLINE/PubMed, Embase, PsycINFO, CINAHL, and Google Scholar) for quantitative evaluations published up to March 2026 (CRD42022316044). The Newcastle-Ottawa Scale and Cochrane Risk of Bias-2 tool were used for quality assessments, and certainty of evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Findings were narratively synthesized using the SWiM (Synthesis Without Meta-analysis) framework. RESULTS: We identified 4038 records, and 16 papers published between 2007 and 2024 met the inclusion criteria (asthma=13, COPD=2, both=1). Three were randomized controlled trials, all rated high risk of bias. Of the other studies, 5 had low risk, 6 had moderate risk, and 2 had high risk of bias. Effectiveness and patient-centeredness were most frequently reported, with 12 papers each. Eight papers were on equity, 5 each on efficiency and safety, and 4 on timeliness. In asthma, modest disease control improvements were reported in 27.8% (42/151) of participants using patient portals with home visit support versus portal use alone (35/150, 23.3%). In COPD, one large, interrupted time series study (N=909,724) reported post-implementation reductions in hospitalizations (slope change from 1.33 to -4.38 per 10,000 patients per month; P<.001) but no mortality benefits. Short-term improvements in asthma-related quality of life were observed among patient portal users (mean Mini Asthma Quality of Life Questionnaire score change of 0.67; 95% CI 0.36-0.98) but with no sustained effects. In terms of equity, several digital access barriers were noted. Assessments of efficiency outcomes were largely subjective, and safety events were weakly described. Across all outcome domains, GRADE assessment indicated low to very low evidence certainty. CONCLUSIONS: This review found low to very low certainty of evidence on the impacts of patient portals on quality of care for asthma and COPD. While modest disease control improvements and short-term quality-of-life gains were noted in asthma, and reduced hospitalizations in COPD were observed, the evidence base remains limited and methodologically weak. This review cautions against a reliance on patient portals for clinical management of asthma and COPD and highlights that more methodologically robust primary studies are needed to identify how portal functions may yield clinically meaningful benefits for patients with chronic respiratory disease.