Understandability of statin patient information leaflets in the UK: a mixed-methods cross-sectional evaluation

Statins are the UK's most prescribed medicine and are used more in deprived populations. Patient Information Leaflets (PILs) included in medication packaging may support safe, effective use, but only if they are understandable. Guidance states PILs should have a reading age of ≤13-years, and regulators require that ≥80% of patients answer comprehension questions correctly on them when 'user tested'.

To provide the first independent evaluation of the readability and comprehension of UK statin PILs.

Study 1: Cross-sectional analysis of the reading age of 39/40 of the UK's approved statin PILs. Study 2: Cross-sectional survey with a representative sample of 517 UK adults aged 40-74.

Study 1: Reading age was assessed using four readability formulas, with additional scores calculated after adjusting for potentially familiar technical terms. Study 2: Two PILs (atorvastatin [MSN] and rosuvastatin [Ranbaxy]) were randomly selected and user tested with participants. They answered eight comprehension questions per PIL; responses were double-scored.

Study 1: No PIL met the recommended reading age. Median reading age was 15.9 years (15.0 after adjustment). Atorvastatin PILs were least readable. Study 2: Key messages were poorly understood; for atorvastatin, 5/8 items met the≥80% criterion; for rosuvastatin, 2/8 met it. Key safety and use messages were frequently misunderstood.

UK statin PILs do not meet recommended readability or comprehension standards and are likely to be difficult to understand for many users. Improving clarity and usability is essential to support equitable understanding and safe, informed long-term statin use.