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.

Comparison of trichloroacetic acid with other protein-precipitating agents in enriching abnormal prion protein for Western blot analysis.

Detection of the abnormal or the pathogenic form of prion protein (PrP(Sc)) by Western blot (WB) is challenging, especially, for samples derived from cell cultures that contain low levels of PrP(Sc). A variety of PrP(Sc) concentration methods have been reported with various PrP(Sc) recovery efficiencies. Ultracentrifugation is one of the methods used frequently to enrich the pathogenic form of PrP(Sc) prior to WB analyses. The resulting PrP(Sc) pellet is extremely insoluble and often requires sonication to be dissolved, potentially generating aerosols. We modified the common protein-precipitating protocol using trichloroacetic acid to concentrate PrP(Sc) by slow-speed centrifugation, followed by solubilization of the pellets with 6 mol/L urea prior to sodium dodecyl sulphate -- polyacrylamide gel electrophoresis and WB analyses. Comparative studies suggest this simple trichloroacetic acid protocol was more effective in enriching PrP(Sc) presented in cell cultures and brain homogenates than other reported protein-precipitating methods. Furthermore, incorporation of the urea treatment step to dissolve the precipitated PrP(Sc) pellets helped to reduce the infectivity of PrP(Sc).

Susceptibility of cell substrates to PrPSc infection and safety control measures related to biological and biotherapeutical products.

Concerns over the potential for infectious prion proteins to contaminate human biologics and biotherapeutics have been raised from time to time. Transmission of the pathogenic form of prion protein (PrP(Sc)) through veterinary vaccines has been observed, yet no human case through the use of vaccine products has been reported. However, iatrogenic transmissions of PrP(Sc) in humans through blood components, tissues and growth hormone have been reported. These findings underscore the importance of reliable detection or diagnostic methods to prevent the transmission of prion diseases, given that the number of asymptomatic infected individuals remains unknown, the perceived incubation time for human prion diseases could be decades, and no cure of the diseases has been found yet. A variety of biochemical and molecular methods can selectively concentrate PrP(Sc) to facilitate its detection in tissues and cells. Furthermore, some methods routinely used in the manufacturing process of biological products have been found to be effective in reducing PrP(Sc) from the products. Questions remain unanswered as to the validation criteria of these methods, the minimal infectious dose of the PrP(Sc) required to cause infection and the susceptibility of cells used in gene therapy or the manufacturing process of biological products to PrP(Sc) infections. Here, we discuss some of these challenging issues.