Pharmacist-led communication strategies using social norm nudging and numerical information: a randomized field study on the willingness of Japanese patients to initiate treatment.

Abstract

This study aimed to investigate the effectiveness of pharmacist-led communication strategies [social norm nudging and numerical adverse event (AE) information] in improving patients' willingness to initiate medication according to subjective numeracy skills in a real-world pharmacy setting. A randomized field study with a 2 × 2 factorial design was conducted across 19 community pharmacies in Sapporo, Hokkaido, Japan. Among 54 enrolled patients, 51 with complete response to mandatory questionnaire items and newly prescribed medications for hypertension, diabetes, or dyslipidaemia were randomly assigned to one of four counselling conditions combining numerical or non-numerical AE information with or without social norm nudging. Medication willingness was evaluated before and immediately after counselling using a 7-point scale. Subjective numeracy skills were measured using the preference subscale of the Subjective Numeracy Scale. Main effects and interaction effects were examined using the analysis of covariance. Social norm nudging significantly improved medication willingness, with a moderate effect size, and this effect remained consistent across numeracy levels. Numerical AE information was not associated with a significant change in medication willingness. No significant interactions were identified between interventions and subjective numeracy, contrary to findings reported in previous online surveys. In this study, social norm nudging was effective in improving medication willingness during routine pharmacy counselling, irrespective of patients' numeracy levels. The absence of numeracy-moderated effects warrants further investigation. These findings provide a foundation for future clinical trials investigating long-term medication adherence outcomes.