AF designed the data collection tools, analysed the data, and drafted and revised the paper. AF is the guarantor. AMM and GH devised the study. AMM designed the data collection tools and advised on the data analyses. GH, CM and AMM offered guidance on the initial drafting of the paper and helped revise the paper. SR conducted the GEE analysis and drafted these sections of the paper. All authors read and approved the final manuscript. All authors had access to and can take responsibility for the data and analysis.