Temporal trends in voluntary behavioural changes during the early stages of the COVID-19 outbreak in Japan

Kashima, Saori; Zhang,

Objectives This study evaluated the characteristics of individuals with voluntary behavioural changes (cancellation and postponement of bookings) during the early stages of the COVID-19 outbreak in Japan. In addition, the temporal trends of these changes were captured. Study design A cross-sectional study and a time-series study were conducted. Methods A nationwide retrospective panel survey was conducted at the end of March 2020 (n = 1052). Odds ratios for cancellations/postponements with respect to individual characteristics were calculated in the analysis. To determine the temporal trend, the incidence ratios were compared throughout the time-series analysis for four time periods: Period 1, before the announcement of the Public Health Emergency of International Concern (PHEIC) from the World Health Organisation (WHO) (January 1 – 31); Period 2, after the announcement of PHEIC (February 1 – 26); Period 3, after the announcement of school closures by the Japanese government (February 27 – March 11); and Period 4, after the announcement of the pandemic by the WHO (March 12 – 31). Results In total, 72% of respondents cancelled or postponed their bookings at least once, and about half of the changes occurred in Period 3. Elderly individuals’ changes in gatherings were, on average, 5.9 times (95% confidence interval [CI] 1.9–17.9) higher than those of young individuals. The incidence rate of change in gatherings during Period 3 was 7.11 times (95% CI 5.16–9.81) higher than in Period 2 and 3.15 times (95% CI 2.25–4.43) higher than in Period 4. Significant interaction terms were observed in age and residential city size, but not sex, of the respondents. Conclusions A significant proportion of the Japanese population voluntarily changed their behaviour during the early stages of the COVID-19 outbreak, and the government’s announcement of school closures was a key trigger during this time.