Background:

Patient portal use could help improve diabetes patients’ care and health outcomes due to the functionalities such as appointment booking, e-messaging, repeat prescription ordering that enable patient-centred care and improve the patient’s self-management of the disease.

Objective:

To summarise the evidence regarding the use of patient portal (portals that are connected to the electronic healthcare record) or patient portal functionality (e.g. appointment booking or e-messages) and their reported associations with health and healthcare quality outcomes among adult diabetes patients.

Methods:

We searched the databases including Medline, Embase and Scopus and reported the review methodology using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three independent reviewers screened titles and abstracts, and two reviewers assessed full-texts of relevant studies and performed data extraction and quality assessments of the included studies. We used the Cochrane Collaboration Risk of Bias Tool and the National Heart, Lung and Blood Institute (NHLBI) Study Quality Assessment Tools to assess the risk of bias of the included studies. Data was summarised through narrative synthesis.

Results:

Twelve studies were included in this review. Five studies reported overall patient portal use and its association with diabetes health and healthcare quality outcomes. Six studies reported E-messaging or email use associated outcomes and two studies reported prescription refill associated outcomes. Reported associations included the association between patient portal use and blood pressure, LDL cholesterol or BMI. Few studies reported outcomes regarding the use of patient portals and healthcare utilisation measures such as office visits, emergency department visits and hospitalisations. Limited number of studies reported overall quality of care for diabetes patients who used patient portals.

Conclusions:

The included studies mostly reported improved glycaemic control outcomes for diabetes patients who used patient portals. However, limitations of studying the effects of patient portals exist that do not guarantee whether the outcomes reported were completely a result of patient portal use or if confounding factors exist. Randomised controlled trials and mixed-methods studies could help understand the mechanisms involved in diabetes patient health outcome improvements and patient portal use. Clinical Trial: The protocol of this systematic review was registered in PROSPERO (registration number: CRD42019141131) and published in JMIR Research Protocols (RR1-10.2196/14975).