Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040
Original Article
Changes in Smoking Behavior Since the Declaration of the COVID-19 State of Emergency in Japan: A Cross-sectional Study From the Osaka Health App
Shihoko KoyamaTakahiro TabuchiSumiyo OkawaTakayoshi KadobayashiHisaya ShiraiTakeshi NakataniIsao Miyashiro
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2021 Volume 31 Issue 6 Pages 378-386


Background: In April 2020, the Japanese government declared a state of emergency due to the COVID-19 pandemic, and infection control measures, including requests to work from home and stay-at-home restrictions, were introduced. This study examined changes in smoking behavior during the COVID-19 state of emergency.

Methods: An online cross-sectional survey was conducted in Osaka, Japan. To assess differences in smoking behavior among 5,120 current smokers before and after the declaration of a state of emergency, prevalence ratios (PRs) for two outcomes, increased smoking and quitting smoking, were calculated using multivariable Poisson regression, adjusting for potential covariates.

Results: We found 32.1% increased the number of cigarettes smoked and 11.9% quit smoking. After adjustment for all variables, we found risk factors for COVID-19 (men and older age group) had both significantly higher PR for quitting smoking (men: PR 1.38; 95% confidence interval [CI], 1.17–1.62) and participants aged ≥65 years: PR 2.45; 95% CI, 1.92–3.12) and significantly lower PR of increased smoking (men: PR 0.85; 95% CI, 0.78–0.93 and participants ≥65 years: PR 0.38; 95% CI, 0.29–0.49). Additionally, respondents working from home or living alone had significantly higher PR for increased smoking (working from home: PR 1.29; 95% CI, 1.17–1.41 and living alone: PR 1.23; 95% CI, 1.10–1.38) and respondents who changed from cigarettes to heated tobacco products (HTPs) had significantly lower PR for quitting smoking (PR 0.150; 95% CI, 0.039–0.582).

Conclusions: We suggest people who have high-risk factors for COVID-19 might change their smoking behavior for the better, while people who work from home or live alone might change their smoking behavior for the worse, during the COVID-19 state of emergency. Additionally, changing from smoking cigarettes to using HTPs makes smokers less likely to quit.

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© 2021 Shihoko Koyama et al. This is an open access article distributed under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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