Effectiveness of a community health literacy intervention: a stepped-wedge cluster randomized trial

Background

Health literacy is a major public health challenge and a key determinant of socioeconomic health inequalities. Although health literacy interventions hold promise, the evidence remains limited, particularly interventions targeting individuals with limited health literacy. This study evaluated the effectiveness of a co-created, community-based health literacy intervention for adults in the Netherlands.

Methods

A pragmatic stepped‑wedge cluster randomized trial was conducted, using questionnaire data collected at four time points over 9 months. The intervention, consisting of group sessions on positive health, was delivered across five municipalities. Intervention effects were estimated using mixed-effects models. The primary outcome was positive health consisting of six domains: physical health, mental health, participation, quality of life, daily functioning and meaningfulness. Secondary outcomes included health literacy and health- and social care-related quality of life.

Results

In total, 100 participants were enrolled in the study (83% women, mean age: 55.7) of whom 89 received the intervention. No significant effects were found on the domains of positive health, health literacy (β = 0.09, 95% CI [−0.65, 0.83]), social care-related quality of life (β = 0.070, 95% CI [−0.016, 0.155]) and health-related quality of life (β = 0.035, 95% CI [−0.027, 0.098]). Notably, only 25% of the sample was classified as having limited health literacy at baseline.

Conclusions

Although no statistically significant effects were observed, the improvement in social care-related quality of life may still be clinically relevant (9.3%). The absence of significant findings may be explained by limited statistical power and challenges in reaching the intended population with limited health literacy. Further research is needed to assess the intervention’s effectiveness, with particular attention to targeted recruitment and retention in complex designs such as stepped wedge trials.

Key messages

• A community-based health literacy intervention showed no statistically significant effects on positive health, with a possible improvement in social care-related quality of life.

• Evaluating community‑based interventions with priority populations requires substantial time and resources for recruitment and retention particularly with complex designs such as stepped‑wedge trials.