Measurement, drivers, and outcomes of patient-initiated secure messaging use and intensity: a scoping review.

Objective: Use of secure messaging through the patient portal has increased in recent years. We compile evidence of how patient-initiated secure messaging has been measured, factors associated with use, and effects on individual and organization-level outcomes. Materials and Methods: We conducted a scoping review of articles published through October 2023 by systematically searching PubMed, Embase, and CINAHL. The search identified 2574 articles; 220 were selected for full text review and 78 met eligibility criteria. Factors and outcomes associated with messaging were organized according to the System Engineering Initiative for Patient Safety (SEIPS) 2.0 framework. Results: Of 78 included studies, 70 (90%) specified the measurement approach: measuring any messaging use versus none (binary measure) (27/70; 39%), intensity of use (34/70; 49%), or both (9/70; 13%). Studies predominantly examined patient (vs clinician) characteristics (48/78; 62%), findings that patients of female sex, White race, higher socioeconomic status, and greater comorbidity were more likely to message and with greater intensity. Factors in other domains of the SEIPS framework such as tasks (7/78; 9%), tools/technology (5/78; 6%), organizational (7/78; 9%), and environmental (11/78; 14%) factors were examined less frequently, with mixed findings. Outcomes of secure messaging (23/78; 30%) were generally favorable with respect to clinical outcomes (10/23; 43%), efficiency (5/23; 22%), and care experience (5/23; 22%) and mixed with respect to health services use. Discussion: Patient-initiated messaging use has been variably measured, with notable gaps in our understanding of the role of organization-level factors. Conclusion: Evidence is needed to inform approaches implemented by healthcare systems to manage the growing volume of patient-initiated messages.