Enhancing parental awareness on multiple chemical sensitivities: lessons from repeated cross-sectional questionnaire surveys on children.

BACKGROUND: Multiple chemical sensitivity (MCS) is not yet familiar to the public. Patients suffer from a lack of understanding of their rare condition by those around them. This study aimed to (1) investigate the public awareness rate of MCS and (2) whether respondents who repeatedly responded to a survey about MCS have significantly increased their awareness of MCS compared to those who responded only once. METHODS: We distributed a self-reported questionnaire to parents of all elementary and junior high school students in Joets City, Niigata, in 2010 and 2017. The questionnaire was completed by 13,444 parents in 2010 and 7039 parents in 2017 (N = 20483). Using the same questionnaire multiple times in our surveys, we utilized the nature of a natural experiment, which is the presence of identical respondents in the dataset. We performed multivariate regression analyses. RESULTS: The parental awareness of MCS was 64.2% on average from our surveys. Multivariate regression analyses revealed that the awareness of MCS was 6% points higher among parents who responded to the survey repeatedly than among parents who responded only once. CONCLUSIONS: Repeated conducting questionnaire surveys had a positive impact on MCS awareness of parents. Conducting surveys has the potential to work as a public awareness campaign to reduce the prevalence of MCS.