Pandemic fatigue and attenuated impact of avoidance behaviours against COVID-19 transmission in Hong Kong by cross-sectional telephone surveys.

OBJECTIVES: This study aims to explore the attenuated impact of reported avoidance behaviours adherence on the transmission of COVID-19 through cross-sectional surveys in Hong Kong, in order to make up for the lack of research on avoidance behaviours fatigue. DESIGN: 40 cross-sectional telephone surveys. SETTING: All districts in Hong Kong. PARTICIPANTS: 31 332 Cantonese or English-speaking participants at age of 18 years or above. METHODS: We collected data on behaviours and estimated the average effective reproduction number ([Formula: see text]) among the Hong Kong adult population during the COVID-19 epidemic wave in November-December 2020 and compared with the preceding epidemic in June-July 2020. RESULTS: We observed a reduction in adherence to voluntary avoidance behaviours due to pandemic fatigue, but continued adherence to regulated avoidance behaviours. The average [Formula: see text] during the post-work from home period was higher in November-December wave with estimated [Formula: see text] of 0.81 (95% CI: 0.75 to 0.87) compared with the June-July wave with an [Formula: see text] of 0.67 (95% CI: 0.60 to 0.75). CONCLUSIONS: The declined effectiveness of social distancing interventions in reducing COVID-19 transmission was associated with fatigue with voluntary avoidance behaviours in Hong Kong population, implying a need for the government to reinvigorate the public to maintain effective pandemic control.