Patient Experiences With Online Laboratory Test Presentations From Access to Activation: Systematic Review.

Background: Federal regulations require that laboratory test results be released to patients through online portals in near-real time, often before clinicians review or contextualize them. While these policies expand transparency and affirm patients' rights to their health information, access alone does not ensure that patients can make sense of their results or determine when and how to act. How regulatory mandates for transparency translate into appropriate engagement remains poorly understood. Objective: We aim to synthesize evidence on how patients access, interpret, and act upon laboratory test results delivered online; identify factors associated with comprehension and engagement; and evaluate how display design, clinical workflow, and patient characteristics shape engagement across the access-to-activation continuum. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidance, we systematically searched 5 databases-Web of Science, Embase, PubMed, CINAHL, and Library, Information Science & Technology Abstracts-for English-language, peer-reviewed empirical studies published from January 2013 through April 2026, supplemented by hand searching and citation tracking. Eligible studies examined patient access to, interpretation of, or responses to laboratory results delivered through portals. Records were independently screened, appraised for methodological quality, and synthesized using thematic analysis across a 3-stage continuum: access, interpretation, and activation. The protocol was not registered. Results: Thirty-nine studies met the inclusion criteria; most were from the United States. Retrospective analyses documented increases in result viewing, secure messaging, and follow-up visits after immediate-release policies. Patients value timely access but often struggle to determine the significance of borderline values and when follow-up is warranted. Visual and textual cues can improve clarity but may also overemphasize minor deviations or inadequately signal clinically significant findings. Patients frequently monitor portals and initiate contact to confirm clinician review, indicating that increased portal activity often reflects efforts to resolve uncertainty rather than confident self-management. Disparities in access, comprehension, and confidence were observed among older adults, non-English-speaking patients, those with public insurance, and those with lower health or digital literacy. Measures of comprehension and engagement varied widely. Conclusions: Expanded online access improves transparency but does not guarantee accurate interpretation or appropriate follow-up. In contrast to prior reviews examining patient perceptions, comprehension, and presentation formats in isolation, this synthesis traces patient experiences across an access-interpretation-activation continuum, revealing how interpretive challenges and emotional responses compound across stages. Meaningful activation depends not only on display clarity but on how informational, emotional, and workflow factors shape patients' decisions across stages. Designing for activation, therefore, requires a holistic, systems-level approach that aligns result presentation, interpretive support, and clinical workflow to signal the clinical significance of laboratory test results and guide appropriate follow-up. Such approaches must be responsive to the needs of patients across diverse literacy, language, and clinical contexts.