Of the 1433 respondents who completed the baseline assessment, 896/1433 (63%) respondents agreed to participate and completed the March follow-up survey (Figure 4 ). Demographic characteristics of respondents in the baseline and followup surveys are shown in Table 2 . Compared to respondents completing both baseline and follow-up surveys, respondents lost to follow-up were younger (x 2 = 14.24, p = 0.001) and more likely to be single (x 2 = 20.26, p,0.001). Overall, the low Cohen effect sizes (,0.3) showed that the demographics of respondents who completed both the baseline and follow-up surveys were comparable to those of the general population of Hong Kong [61] .