Impact of a co-produced, complex health promotion intervention among partners of women with prior gestational diabetes: A secondary analysis of the Face-it Randomised Trial

Background and aims: Partners of women with prior gestational diabetes mellitus (GDM) may have an increased risk of cardiometabolic conditions. Adopting healthy behaviours may mitigate this risk. It remains unclear whether a family-based intervention influences behaviour change mechanisms in partners. The Face-it intervention was a randomised complex health promotion intervention targeting families in the first year postpartum after GDM. This study aims to evaluate the impact of the Face-it intervention compared to usual care on behaviour change mechanisms (social support, motivation, self-efficacy, diabetes risk perception and health literacy) among partners to women with prior GDM at 1-year follow-up.
Materials and methods: The Face-it trial included questionnaires and health examinations obtained at 10–14 weeks postpartum (baseline) and 1-year postpartum (follow-up). Partners followed the women’s assigned randomisation. The intervention comprised three components: (i) home visits with tailored family-based counselling, (ii) digital health coaching, and (iii) structured cross-sectoral communication. Descriptive statistics and mixed or generalised linear mixed models were used, adjusting for outcome measures at baseline and study site as random effects. Analyses followed the intention-to-treat principle.
Results: A total of 131 partners were randomised to the intervention group, and 63 to the usual care group. The two groups were comparable at baseline in age (34.4 ± 5.5 vs. 33.9 ± 5.5 years), BMI (28.0 ± 4.5 vs. 28.4 ± 5.4 kg/m²), and fasting glucose levels (5.4 ± 0.5 vs. 5.4 ± 0.6 mmol/L). At 1-year follow-up, the intervention group had a higher score for social support encouragement for eating habits (10.7 [9.9;11.4] vs. 9.2 [8.2;10.2], p=0.02) and higher odds for reporting changed behaviour to reduce diabetes risk (42.5% vs. 31.5%, OR 2.4 [1.1; 5.3], p=0.03). No differences were found between the groups for social support for participation in physical activity (18.1 [16.6; 19.6] vs. 17.8 [15.9; 19.7, p=0.75), motivation (5.4 [5.3; 5.6] vs. 5.2 [4.9; 5.4], p=0.10), self-efficacy (31.8 [31.0; 32.5] vs. 31.8 [30.9; 32.7], p=0.95), high/moderate perceived risk of getting diabetes (11.3% vs. 13.0%, OR 0.8 [0.3; 2.8], p=0.83), health literacy in actively engaging with health (2.5 [2.4; 2.6] vs. 2.4 [2.3; 2.6], p=0.59) or health literacy in engaging with healthcare providers (3.7 [3.5; 3.9] vs. 3.6 [3.4; 3.8], p=0.52).
Conclusion: After 9 months of intervention, partners to women with prior GDM achieved higher scores in the following possible behaviour change mechanisms: social support encouragement for eating habits and higher odds for reporting behaviour changes to reduce the risk of diabetes compared to usual care.