Effectiveness and Acceptability of Asynchronous Digital Health in Asthma Care: Mixed Methods Systematic Review
Authors: Uzzaman Nazim , Hammersley Victoria , McClatchey Kirstie , Sheringham Jessica , Singh Diksha , Habib GM Monsur , Pinnock Hilary 
Published: December 2024

Background
Asynchronous digital health (eg, web-based portal, text, and email communication) can overcome practical barriers associated with in-person and remote synchronous (real-time) consultations. However, little is known about the effectiveness and acceptability of asynchronous digital health to support care for individuals with asthma (eg, asthma reviews).

Objective
We aimed to systematically review the qualitative and quantitative evidence on the role of asynchronous digital health for asthma care.

Methods
Following Cochrane methodology, we searched 6 databases (January 2001-July 2022; search update: September 2023) for quantitative, qualitative, or mixed methods studies supporting asthma care using asynchronous digital health. Screening and data extraction were duplicated. We assessed the risk of bias in the clinical outcomes of randomized controlled trials included in the meta-analysis using the revised Cochrane risk of bias tool. For the remaining studies, we evaluated the methodological quality using the Downs and Black checklist, critical appraisal skills program, and mixed methods appraisal tool for quantitative, qualitative, and mixed methods studies, respectively. We determined the confidence in the evidence using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) criteria. We conducted a meta-analysis of trial data and a thematic analysis of qualitative data.

Results
We included 30 studies (20 quantitative, 6 qualitative, and 4 mixed methods) conducted in 9 countries involving individuals with asthma, their caregivers, and health care professionals. Asynchronous digital consultations linked with other functionalities, compared to usual care, improved asthma control (standardized mean difference 0.32, 95% CI 0.02-0.63; P=.04) and reduced hospitalizations (risk ratio 0.36; 95% CI 0.14-0.94; P=.04). However, there were no significant differences in quality of life (standardized mean difference 0.16; 95% CI –0.12 to 0.43; P=.26) or emergency department visits (risk ratio 0.83; 95% CI 0.33-2.09; P=.69). Patients appreciated the convenience of asynchronous digital health, though health care professionals expressed concerns. Successful implementation necessitated an organizational approach. Integrative synthesis underscored the ease of asking questions, monitoring logs, and medication reminders as key digital functionalities.

Conclusions
Despite low confidence in evidence, asynchronous consultation supported by digital functionalities is an effective and convenient option for nonemergency asthma care. This type of consultation, well accepted by individuals with asthma and their caregivers, offers opportunities for those facing challenges with traditional synchronous consultations due to lifestyle or geographic constraints. However, efficient organizational strategies are needed to manage the associated workload.

Trial Registration
PROSPERO CRD42022344224; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=344224

International Registered Report Identifier (IRRID)
RR2-10.1371/journal.pone.0281538