JMIR Publications

ABSTRACT

Background:

Gestational Diabetes Mellitus (GDM) is characterised by hyperglycaemia in pregnancy and typically resolves after birth. Women with GDM have an increased risk of developing type 2 diabetes mellitus (T2DM) later in life compared to those with a normoglycemic pregnancy. Risk factors for T2DM post-GDM include high body mass index (BMI), increasing age, multiparity, and pre-pregnancy complications. Whilst diabetes prevention interventions (DPI) have been developed to delay or prevent the onset of T2DM, few studies have provided process evaluation (PE) data to assess the mechanisms of impact, quality of implementation or contextual factors that may influence the effectiveness of the intervention. PE theoretical frameworks were originally introduced by researchers to provide a systematic and stepwise approach to planning the design of health behaviour change interventions. However, there is still limited consensus across PE frameworks on how to define and measure PE components, and a lack of guidance on how to deliver PE theoretical frameworks in practice in complex interventions.

Objective:

The primary aim of this review was to identify and evaluate PE data and how these link to outcomes of randomised control trials of T2DM prevention interventions for women with GDM.

Methods:

A systematic review was conducted to identify studies published from 2005–2020. Five electronic bibliographic databases (Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE) were searched to identify relevant studies. The Medical Research Council’s PE framework of complex interventions was used to identify key PE components. The mixed-method appraisal tool (MMAT) was used to assess the quality of included studies.

Results:

Twenty-four studies were included, however, only five explicitly reported a PE theoretical framework. The studies involved three methods of intervention delivery including in-person (n=7), digital (n=7) and hybrid (n=9). Two studies conducted pilot RCTs assessing the feasibility and acceptability of their interventions including recruitment, participation, retention, program implementation, adherence, and satisfaction, and one study assessed the efficacy of a questionnaire to promote food and vegetable intake. Whilst most studies linked PE data with study outcomes, it was unclear which of the reported PE components were specifically linked to the positive outcomes.

Conclusions:

We need clearer guidance and robust frameworks for conducting PEs for the development and reporting of DPIs for women with GDM.