Mediators of the association of limited English health literacy with medication non-adherence among Singaporean elderly

Abstract

Background: In Singapore, English is predominantly used on prescription medication labels (PMLs). However, many older Singaporeans cannot read English, and among those who read English, their English health literacy (EHL) proficiency varies. It is thus pertinent to examine the link between EHL and medication use outcomes in this population. The present research aims to address this question. Methods: Data from a national survey, on 1167 home-dwelling elderly on ⩾1 prescribed medication was analysed. The validated Health Literacy Test for Singapore was used to determine EHL. Medication non-adherence was self-reported. Path analysis examined the association between limited EHL and medication non-adherence and tested possible mediators. Results: Limited EHL was associated with medication non-adherence (total effect=0.35; p -value: 0.032), and ‘uncertainty in taking medications correctly due to difficulty in understanding written information on PMLs’ was a significant mediator (indirect effect=0.23, 95% confidence interval (0.12–0.39)). Conclusions: Elderly people with limited EHL were significantly more likely than those with adequate EHL to report that they were uncertain about taking medications correctly because they had difficulty understanding the information on PMLs and this misunderstanding contributed to medication non-adherence. Interventions focused on incorporating bilingual text and/or pictograms on PMLs may reduce uncertainty in taking medication correctly and improve medication adherence among the elderly.