Acceptability of health-only versus climate-and-health framings in lifestyle-related climate-sensitive health counselling : results of a randomised survey experiment in Germany

Background: Climate-sensitive health counselling (CSHC) delivered by health professionals could promote individual patients and planetary health, particularly within lifestyle counselling. However, health professionals’ uncertainty about the acceptability of CSHC remains a barrier to implementation. This study aimed to establish the effects of different topics and framings on patients’ acceptability of lifestyle-related CSHC. Methods: We conducted a randomised survey experiment with a 2 × 3 mixed factorial design embedded in a larger survey in the Health-Related Beliefs and Health Care Experiences (HeReCa) panel study in Germany, an online panel of the general adult population from five of the 16 federal states across Germany. Participants were randomly assigned in a 1:1 ratio to one of two topics (either diet or physical activity) and were presented with three vignettes in a random order (framing A framed the given advice in health terms only; framing B presented the advice in terms of health and climate co-benefits; and framing C emphasised health, climate co-benefits, and climate risks). Topic served as the between-subject factor, and framing served as the within-subject factor. We hypothesised that the acceptability of CSHC would differ according to framing, but not according to topic. The primary outcome variable was the acceptability of the CSHC vignettes, measured using an acceptability score based on four items (affective attitude, burden, ethicality, and perceived effectiveness), rated on a five-point Likert scale (1–5 score: 1=not acceptable, 5=very acceptable). We refined our hypotheses based on subpopulations generated from a Left–Right Self-Placement for political orientation and climate change attitude test. We applied descriptive statistics, t tests, and a mixed ANOVA to the full and stratified samples. Findings: Of 3346 individuals who signed up for the HeRaCa panel between November, 2019, and June, 2020, 3163 participants of the panel (94·5%) were given the survey and 1516 (47·9%) submitted responses between April and June, 2022. 25 participants with incomplete data were excluded, and 1491 participants were included in the mixed ANOVA primary analysis. 748 participants were allocated to the diet group and 743 to the physical activity group. The mean age of the full sample was 55·6 years (SD 14·2). Excluding 62 participants with missing values, 814 (57·0%) were female and 613 (49·2%) were male; two participants (0·1%) self-identified as a diverse gender. In the whole cohort, the mean acceptability score of framing A was 4·09 (SD 0·71), was 3·67 (0·91) for framing B; and was 3·55 (0·97) for framing C. Mixed ANOVA revealed a significant and large effect of framing (partial η=0·18, p<0·001), and a significant but negligible effect of topic (partial η=0·004, p=0·021) on CSHC acceptability. Stratified analysis revealed that framing effects were less pronounced among participants alarmed about climate change or positioned politically to the left. Interpretation: Health-only framings of CSHC yield greater acceptability than health-and-climate framings across all subgroups. Differences are most pronounced among participants cautious or doubtful about climate change. These findings highlight tensions between the planetary health aims of CSHC and acceptability to patients, which could be alleviated by applying patient-centred communication techniques.