The effectiveness and decay of public health policy actions on infection-control behaviour in the general public: Evidence from a low-COVID prevalence jurisdiction

Background: Public health policies designed to influence individuals’ infection-control behaviour are a tool for governments to help prevent the spread of disease. Findings on the impacts of policies are mixed and there is limited information on the effects of removing restrictions and how policies impact behavioural trends. Methods: We use low-acuity emergency department visits from 12 hospitals in New Brunswick, Canada, (January 2017 –October 2021) as a proxy for infection-control behaviour and provide insight into the effects of the COVID-19 virus on a population with a low prevalence of cases. Quasi-experimental techniques (event studies) are applied to estimate the magnitude and persistence of effects of specific events (e.g., policy changes), to control for COVID-19 cases and vaccines, and to explore how the effectiveness of policy changes during the pandemic as more policies are introduced. Results: Initial tightening of restrictions on March 11, 2020 reduced low-acuity emergency department visits by around 60% and reached a minimum after 30 days. Relaxing policies on social gatherings and personal services gradually increased low-acuity emergency department visits by approximately 50% after 44 days. No effects were found from policies lifting all restrictions, and reinstating a state of emergency on July 31, 2021, and September 24, 2021. Conclusion: These results suggest that policy interventions are less likely to be effective at influencing infection control behaviour with time and more policies introduced, and that tracking and publicly reporting case numbers can influence infection control behaviour.