Influence of the social determinants on adherence to a lifestyle modification intervention in people with prediabetes

eng Introduction: Type 2 Diabetes Mellitus (T2D) is a highly prevalent chronic condition that represents a significant global health and social burden. Lifestyle modification interventions—such as healthy eating and regular physical activity—have proven effective in preventing or delaying the onset of T2D in individuals with prediabetes. However, the ability to adopt these changes does not depend solely on individual factors; it is also shaped by the social determinants of health (SDH), with gender and social class playing important roles. Objective: To analyse the influence of SDH and explore the contextual and social barriers and facilitators that affect adherence to lifestyle recommendations among individuals with prediabetes and overweight or obesity. Methodology: A sequential explanatory mixed-methods study was conducted, combining a cross-sectional quantitative analysis with a qualitative ethnomethodological approach, framed within the critical-social paradigm. The quantitative phase included participants from the intervention group of the PREDIPHONE clinical trial (n = 86), who received a nurse-led telephone intervention aimed at promoting healthy eating and regular physical activity in individuals with prediabetes and overweight or obesity. Adherence was assessed using a composite index based on the standardised scores of the PREDIMED and REGICOR questionnaires. Correlation analyses were performed to examine the relationship between adherence and age, and chi-square and ANOVA tests were conducted to assess the influence of SDH on adherence to recommendations. In the qualitative phase, semi-structured interviews (n = 15) and a focus group (n = 5) were conducted with participants from the quantitative phase who had shown either high or low adherence. The data were analysed using thematic analysis and critical discourse analysis, applying triangulation and reflexivity as strategies to ensure rigour. Finally, the quantitative and qualitative findings were integrated to provide a more holistic understanding of the phenomenon. Results: Employment status was significantly associated with adherence to healthy lifestyle recommendations, with higher adherence observed among unemployed or retired individuals. Although no statistically significant differences were found by social class or gender, individuals from less advantaged social classes reported economic barriers and lack of time—particularly those working full-time—which hindered adherence to the recommendations. Women reported greater family caregiving responsibilities and less time for self-care, while men reported receiving more family support, generally provided by women in their households. The asymptomatic nature of prediabetes, the influence of health beliefs, and a low perception of risk were identified as key barriers to adopting healthy behaviours. Additionally, the quality of the patient–professional relationship emerged as a critical factor. Empathetic, motivating, and trust-based communication facilitated adherence, whereas lack of follow-up and poor communication generated feelings of abandonment and demotivation. Conclusions: Employment status and time availability are key factors in self-care processes and adherence to lifestyle changes. In addition, gender and social class shape the barriers and facilitators that influence adherence, with women from more disadvantaged social classes emerging as a particularly vulnerable group requiring tailored interventions with an equity-based approach. Finally, the importance of strengthening the patient–professional relationship is emphasised, particularly through shared decision-making processes, as a means to support sustained adherence over time.