Estimating climate change and mental health impacts in Canada: A cross-sectional survey protocol

rural/remote, and/or income based on Statistics Canada data) to account for oversampling and for the biases inherent in the selection strategy. Descriptive statistics will be calculated and will reflect the survey objectives. The prevalence of climate-related subclinical mental health outcomes and emotions and the measures of central tendency for the independent variables will be calculated. Outcome measures (prevalence) and differences between demographic groups will be calculated with 95% confidence intervals. Factor analyses will be conducted for the emotion and subclinical outcome questions [33, 38]. Population-weighted multivariable regression analyses will be used to explore associations between the outcome variables and the independent variables. Discussion This study will provide the first national prevalence estimates of climate change impacts on psychosocial wellbeing in Canada. By examining the prevalence, magnitude, and distribution of climate-sensitive mental health impacts in Canada, this survey will provide important national evidence to support decision-making, adaptation strategies, and public health invest- ments. In addition, although this survey protocol has been developed for use in Canada, the overall design and methods can serve as a foundation for further understanding climate- related mental health outcomes that can inform and support other national and international surveys on this important topic. Finally, the results of this survey will add population-level insights to the global climate change and mental health knowledge base.

Supporting information S1 Table. English version of the full questionnaire. (DOCX) Acknowledgments We extend our thanks to Nia King and Hannah Bayne for translation support. Special thanks to Hannah Bayne and Kelsey Robertson for their support in developing elements of the ques- tionnaire and pre-testing phases. We sincerely thank Doug Elliot from Malatest for his ongo- ing support and troubleshooting ability. Author Contributions Conceptualization: Sherilee L. Harper, Ashlee Cunsolo, Breanne Aylward, Susan Clayton, Kelton Minor, Madison Cooper, Rachael Vriezen. Data curation: Breanne Aylward. Funding acquisition: Sherilee L. Harper, Ashlee Cunsolo. Methodology: Sherilee L. Harper, Ashlee Cunsolo, Breanne Aylward, Susan Clayton, Kelton Minor, Madison Cooper, Rachael Vriezen. Resources: Sherilee L. Harper. Visualization: Sherilee L. Harper, Ashlee Cunsolo. Writing – original draft: Sherilee L. Harper. Writing – review & editing: Sherilee L. Harper, Ashlee Cunsolo, Breanne Aylward, Susan Clayton, Kelton Minor, Madison Cooper, Rachael Vriezen. PLOS ONE Climate change and mental health survey protocol PLOS ONE | https://doi.org/10.1371/journal.pone.0291303 October 11, 2023 9 / 12