Kihara Tomomi, Yamagishi Kazumasa, Iso Hiroyasu, Tamakoshi Akiko
Department of Public Health Medicine, Faculty of Medicine, and Health Services Research and Development Center, University of Tsukuba, Tsukuba, Japan.
Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Japan; Institute for Global Health Policy Research, Bureau of International Health Cooperation, National Center for Global Health and Medicine, Tokyo, Japan.
Prev Med. 2022 Oct;163:107188. doi: 10.1016/j.ypmed.2022.107188. Epub 2022 Aug 9.
Several studies have shown that smoking is a significant risk factor for pneumonia, but it is uncertain to what extent smoking cessation reduces the risk. This study aimed to investigate whether and to what extent smoking cessation is associated with reduced risk of mortality from pneumonia in a Japanese, prospective, community-based cohort. We examined 94,972 individuals (mean age, 57 years; women, 57%) who provided valid responses to a lifestyle questionnaire including questions about smoking. We used years of smoking cessation at baseline to divide former smokers into 5 groups: 0-1 year, 2-4 years, 5-9 years, 10-14 years, and 15 years or more. The endpoint was the underlying cause of death from pneumonia. During the median 19-year follow-up of 94,972 study participants, 1806 died from pneumonia. Multivariable hazard ratios (95% confidence intervals) compared with the current smokers were 1.02 (0.72-1.45) for 0-1 year of smoking cessation at baseline, 0.92 (0.70-1.22) for 2-4 years, 0.95 (0.74-1.21) for 5-9 years, 0.71 (0.53-0.96) for 10-14 years, 0.63 (0.48-0.83) for 15 years or more, and 0.50 (0.36-0.70) for never-smokers. Although smoking increases the risk of pneumonia mortality, the present study showed that the risk of pneumonia mortality decreased with years of smoking cessation, eventually improving to levels similar to those of non-smokers for 10 years or more. Continued smoking cessation may be effective in preventing pneumonia deaths.
多项研究表明，吸烟是肺炎的一个重要风险因素，但戒烟能在多大程度上降低风险尚不确定。本研究旨在调查在一个基于社区的日本前瞻性队列中，戒烟是否以及在多大程度上与降低肺炎死亡率相关。我们对94972名个体（平均年龄57岁；女性占57%）进行了检查，这些个体对一份包括吸烟问题的生活方式问卷给出了有效回答。我们利用基线时的戒烟年限将既往吸烟者分为5组：0 - 1年、2 - 4年、5 - 9年、10 - 14年以及15年及以上。终点指标是肺炎导致的潜在死亡原因。在对94972名研究参与者进行的中位19年随访期间，有1806人死于肺炎。与当前吸烟者相比，基线时戒烟0 - 1年的多变量风险比（95%置信区间）为1.02（0.72 - 1.45），2 - 4年为0.92（0.70 - 1.22），5 - 9年为0.95（0.74 - 1.21），10 - 14年为0.71（0.53 - 0.96），15年及以上为0.63（0.48 - 0.83），从不吸烟者为0.50（0.36 - 0.70）。尽管吸烟会增加肺炎死亡风险，但本研究表明，肺炎死亡风险会随着戒烟年限的增加而降低，最终在戒烟10年及以上时降至与不吸烟者相似的水平。持续戒烟可能对预防肺炎死亡有效。
