Evaluating the Readability of Clinical Trial Content for Patients on Pharmaceutical Company Websites.

Abstract

Background and objectives: Efficient and informed patient recruitment, followed by successful enrolment, is essential for the conduct of clinical trials. As major stakeholders in the research process, pharmaceutical companies have an important role in ensuring that information for patients is available and readable. Several global institutions recommend that patient-facing material be written at a literacy level suitable for 11-12-year-olds. This study assessed the availability and readability of clinical trial sections on UK, Canadian, Australian, and global pharmaceutical company websites.

Methods: The 30 largest global pharmaceutical companies (assessed by market capitalisation in April 2025) were selected. Clinical trial content was reviewed for availability and analysed using three validated readability metrics: the Flesch-Kincaid Grade (FKG), Flesch Reading Ease Score (FRES) and Simple Measure of Gobbledygook (SMOG) Index.

Results: Of 115 websites assessed, 54 were eligible for readability analysis. While 96% of global websites included clinical trial information, 55% of non-global websites lacked such content or contained only external links. FKG scores, which estimate the US school grade level needed for comprehension, averaged 10.9 (± 3.5) for global, 14.2 (± 2.0) for UK, 12.1 (± 2.7) for Canadian and 12.8 (± 1.9) for Australian websites-suggesting readability at high school to college level. FRES scores showed similar trends: 42.2 (± 8.0) global, 31.2 (± 9.4) UK, 38.8 (± 12.3) Canadian and 35.7 (± 12.3) Australian, indicating college-level complexity. SMOG scores suggested that 13-15 years of education were needed to understand the material.

Conclusions: These results indicate that clinical trial information on pharmaceutical company websites is often missing or difficult to read and exceeds recommended literacy levels, which may limit comprehension and engagement. Poor readability disproportionately affects individuals with lower literacy, limited English proficiency or disabilities, creating inequities in trial participation. Applying health literacy and plain-language principles-such as simplifying terminology, shortening sentences and using clear formatting-could improve accessibility and support informed decision-making.