Background Online consultations (OCs) allow patients to contact their care provider online, and have been promoted as a way to address increasing workload and decreasing workforce capacity in primary care. Globally, OCs have been rolled out rapidly due to policy initiatives and the COVID-19 pandemic, though there is a lack of evidence regarding how their design and implementation influence care outcomes. Objective Informed by existing theories, synthesise quantitative and qualitative research on: 1) outcomes of OCs in primary care; 2) how these are influenced by OC system design and implementation. Methods We searched Ovid Medline, Embase, Web of Science, Scopus, NTIS, HMIC, and ZETOC from 2010 to November 2021. We included quantitative and qualitative studies of real-world OC use in primary care, written in English, and published 2010 onwards. Quantitative data were transformed into qualitative themes. For objective 1 we used thematic synthesis informed by the Institute of Medicine domains of healthcare quality. For objective 2 we used Framework Analysis informed by the NASSS framework and Realistic Evaluation. Critical appraisal was conducted using the Mixed Methods Appraisal Tool and strength of evidence judged using GRADE-CERQual. Results We synthesised 62 studies (quantitative n=32, qualitative n=12, mixed methods n=18) in nine countries covering 30 unique OC systems, 13 of which used Artificial Intelligence (AI). Twenty-six were published in 2020 onwards, and 11 were post-COVID-19. There was no quantitative evidence for negative impacts of OCs on patient safety, and qualitative studies suggested perceptions of OC safety varied. Some participants believed OCs improved safety, particularly when patients could describe their queries using unstructured free-text. Staff workload decreased when sufficient resources were allocated to implement OCs, and patients used them for simple problems or could describe their queries using free-text. Staff workload increased when OCs were not integrated with other software or organisational workflows, and patients used them for complex queries. OC systems that required patients to describe their queries using multiple choice questionnaires (MCQs) increased workload for both them and staff. Health costs were reduced when patients used OCs for simple queries, and increased when used for complex ones. Patients using OCs were more likely to be female, younger, native speakers, with higher socioeconomic status than those not using OCs. However, OCs increased primary care access for patients with mental health conditions, verbal communication difficulties, and barriers to attending in-person appointments. Access also increased by providing a timely response to patient queries. Patient satisfaction increased when using OCs due to better primary care access, though could decrease when using MCQ formats. Conclusions This is the first theoretically-informed synthesis of research on OCs in primary care, and includes studies conducted during COVID-19. It contributes new knowledge that in addition to producing positive outcomes such as increased access and patient satisfaction, they can also have negative outcomes such as increased workload and costs. These negative outcomes can be mitigated by appropriate OC system design (e.g. free-text format), incorporating advanced technologies (e.g. AI), and integration into technical and organisational workflows (e.g. timely responses).

BACKGROUND Online consultations (OCs) allow patients to contact their care provider online, and are promoted as a way to address increasing workload and decreasing workforce capacity in primary care. Globally, OCs have been rolled out rapidly due to policy initiatives and COVID-19, though there is a lack of evidence regarding how their design and implementation influence care outcomes. OBJECTIVE Informed by existing theories, synthesise research on: 1) outcomes of OCs in primary care; 2) how these are influenced by OC system design and implementation. METHODS We searched databases from 2010 to November 2021. We included quantitative and qualitative studies of real-world OC use in primary care. Quantitative data were transformed into qualitative themes. For objective 1 we used thematic synthesis informed by the Institute of Medicine’s domains of healthcare quality. For objective 2 we used Framework Analysis informed by the NASSS framework and Realistic Evaluation. Critical appraisal was conducted using the Mixed Methods Appraisal Tool and strength of evidence judged using GRADE-CERQual. RESULTS We synthesised 62 studies in nine countries covering 30 OC systems, 13 of which used Artificial Intelligence (AI). Twenty-six were published in 2020 onwards, 11 were post-COVID-19. There was no quantitative evidence for negative impacts of OCs on patient safety, and qualitative studies suggested varied perceptions of safety. Some participants believed OCs improved safety, particularly when patients could describe their queries using unstructured free-text. Staff workload decreased when sufficient resources were allocated to implement OCs, and patients used them for simple problems or could describe their queries using free-text. Staff workload increased when OCs were not integrated with other software or organisational workflows, and patients used them for complex queries. OC systems that required patients to describe their queries using multiple choice questionnaires (MCQs) increased workload for patients and staff. Health costs reduced when patients used OCs for simple queries, and increased when used for complex ones. Patients using OCs were more likely to be female, younger, native speakers, with higher socioeconomic status than those not using OCs. However, OCs increased primary care access for patients with mental health conditions, verbal communication difficulties, and barriers to attending in-person appointments. Access also increased by providing a timely response to patients’ queries. Patient satisfaction increased when using OCs due to better primary care access, though could decrease when using MCQ formats. CONCLUSIONS This is the first theoretically-informed synthesis of research on OCs in primary care, and includes studies conducted during COVID-19. It contributes new knowledge that in addition to producing positive outcomes such as increased access, OCs can also have negative outcomes such as increased workload. Negative outcomes can be mitigated by appropriate OC system design (e.g. free-text format), incorporating advanced technologies (e.g. AI), and integration into technical and organisational workflows (e.g. timely responses).