Evaluating the health literacy burden of Canada's public advisories: a comparative effectiveness study on clarity and readability.

Background: Significant knowledge gaps exist related to evaluating health product risk communication effectiveness in a regulatory setting. To this end, Health Canada is assessing methods to evaluate the effectiveness of their health product risk communications in an attempt to identify best practices.
Objective: We examined the health literacy burden of Public Advisories (PAs) before and after implementation of a new template. We also compared two methods for their usefulness and applicability in a regulatory setting.
Methods: Suitability assessment of materials (SAM) and readability tests were run by three independent evaluators on 46 PAs (14 "Pre-format change" and 32 "Post-format change"). These tests provided adequacy scores for various health literacy elements and corresponding scholastic grades.
Results: PAs using the new template scored better, with an average increase of 18 percentage points (p < 0.001), on the SAM test. All of the 46 PAs evaluated were rated as "requiring a college/university education comprehension level" using readability tests. Results among readability tests were comparable.
Conclusion: Improvements made to Health Canada's PA template had a measurable, positive effect on reducing the health literacy burden, based on the SAM results. A greater focus on the use of plain language would likely add to this effect. The SAM test emerged as a robust, reliable, and informative health literacy tool to assess risk messages and identify further improvement efforts. Regulators, industry, and public sector organizations involved in communicating health product risk information should consider the use of this test as a best practice to evaluate health literacy burden.