Methodological concerns related to response bias in migrant and seasonal farmworkers.

BACKGROUND: The original objective was to measure the impact of kneepads on musculoskeletal pain in migrant and seasonal farmworkers (MSFWs). Secondary analyses were conducted to quantify the extent to which response bias may have skewed the study's results.

METHODS: Surveys were used to collect data on baseline pain and post-intervention pain, the amount of time participants spent wearing kneepads, and their overall ratings of the intervention.

RESULTS: Participants did not experience significantly less pain with kneepads, and wore them for considerably less than the prescribed amount of time. However, subjects rated them very favorably. Given the strong suspicion of response bias, no firm conclusions could be drawn regarding the intervention.

CONCLUSIONS: Unique survey methodologies must be used with MSFWs, who tend to have low research literacy and are particularly susceptible to response bias. Objective study outcomes are particularly favorable in this population in order to minimize dependence on self-reported measures. Am. J. Ind. Med. 59:1112-1119, 2016. © 2016 Wiley Periodicals, Inc.