Making chemical test results understandable and useful to biomonitoring study participants

Background: Biomonitoring California is charged with returning “meaningful” individual results of environmental chemical analyses in urine and blood to study participants. Challenges include: describing analytical results; explaining uncertain information on potential health effects and exposure sources for some chemicals; and meeting the needs of diverse subjects, including worker populations, non-English speakers, and individuals with varied literacy skills. Usability testing (UT) is critical for developing understandable and appropriate results-return materials.

Methods: Drawing on other UT research, we conducted UT to develop results-return materials for biomonitoring studies among firefighters and other populations. The research team included health educators, toxicologists, epidemiologists, and physicians. Text summaries and graphs were used to describe chemical test results. One-page fact sheets on each chemical presented the most common sources, potential health effects, possible ways to reduce exposure, and resources for more information. To ensure that materials were understandable, culturally appropriate, and useful, UT was conducted with study participants or individuals with similar demographics to the study population. Three rounds of in-depth, one-on-one or small group interviews were conducted to elicit feedback on the content and design of draft materials. Changes were made iteratively between rounds.

Results: UT showed that interviewees preferred receiving test results in multiple formats: tables, graphs, and text. Interviewees also appreciated comparative information, including summary data from the National Health and Nutrition Examination Survey and aggregated data from other participants in the same biomonitoring study. UT also revealed the value of customizable components to meet the needs of various audiences. For example, a document was developed for firefighters to explain how their participation in a study was a contribution both to firefighters and general public health in California.

Conclusions: Usability testing is a critical component in ensuring that clear and meaningful results are returned to biomonitoring study participants.