Supplementary Material for: Sleep Duration and Its Associations with Mortality and Quality of Life in Chronic Obstructive Pulmonary Disease: Results from the 2007–2015 KNAHNES

<b><i>Background:</i></b> While extreme sleep duration negatively affects mortality and health-related quality of life (HRQOL) in general populations, the relationship remains uncertain in patients with chronic obstructive pulmonary disease (COPD). <b><i>Objectives:</i></b> To evaluate the association between sleep duration and mortality and HRQOL in patients with COPD. <b><i>Methods:</i></b> We analyzed 3,349 participants with COPD enrolled in the 2007–2015 Korea National Health and Nutrition Examination Survey (KNHANES). Participants aged 40 years or older with a smoking history and prebronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) &lt;0.7 were eligible. The participants were categorized as short sleepers (&lt;6 h), 6–8 h, and long sleepers (&gt;8) according to self-reported sleep duration. The outcome variables were all-cause mortality and HRQOL. HRQOL was measured using the European Quality of Life-5 Dimensions (EQ-5D) index. <b><i>Results:</i></b> During a median of 6.5 years, 386 (11.5%) participants died. In unadjusted Cox regression analysis, short sleepers with COPD had an increased risk of death (hazard ratio, 1.35; 95% confidence interval [CI]: 1.07–1.71). However, this association was not significant after adjusting for sociodemographic factors, BMI, FEV₁, and comorbidities. In unadjusted and adjusted multiple linear regression, short sleepers had significantly worse HRQOL. The adjusted means of the EQ-5D index were 0.88 (95% CI: 0.87–0.89) for short sleepers, 0.90 (95% CI: 0.90–0.91) for 6- to 8-h sleepers, and 0.89 (95% CI: 0.87–0.91) for long sleepers (<i>p</i> = 0.01). <b><i>Conclusions:</i></b> In patients with COPD, sleep duration was not associated with all-cause mortality. However, short sleep duration was significantly associated with worse HRQOL.

<b><i>背景：</i></b> 尽管极端睡眠时长对普通人群的死亡率及健康相关生活质量（health-related quality of life, HRQOL）存在负面影响，但慢性阻塞性肺疾病（chronic obstructive pulmonary disease, COPD）患者群体中二者的关联仍不明确。<b><i>目标：</i></b> 本研究旨在探讨慢性阻塞性肺疾病患者的睡眠时长与死亡率及健康相关生活质量之间的关联。<b><i>方法：</i></b> 我们对2007-2015年韩国国民健康与营养调查（Korea National Health and Nutrition Examination Survey, KNHANES）中纳入的3349名慢性阻塞性肺疾病患者进行了分析。纳入标准为年龄≥40岁、有吸烟史，且支气管舒张前第一秒用力呼气容积/用力肺活量（forced expiratory volume in 1 s/forced vital capacity, FEV₁/FVC）<0.7的受试者。根据受试者自我报告的睡眠时长，将其分为短睡眠组（<6小时）、正常睡眠组（6-8小时）及长睡眠组（>8小时）。本研究的结局变量为全因死亡率及健康相关生活质量，其中健康相关生活质量采用欧洲五维健康量表（European Quality of Life-5 Dimensions, EQ-5D）指数进行评估。<b><i>结果：</i></b> 中位随访6.5年期间，共有386名（11.5%）受试者死亡。未校正的Cox回归分析结果显示，慢性阻塞性肺疾病短睡眠受试者的死亡风险升高（风险比：1.35；95%置信区间：1.07~1.71）。但在校正社会人口学因素、体重指数（body mass index, BMI）、第一秒用力呼气容积（FEV₁）及合并症后，该关联不再具有统计学意义。未校正及校正后的多重线性回归分析结果均显示，短睡眠受试者的健康相关生活质量显著更差。校正后的欧洲五维健康量表指数均值分别为：短睡眠组0.88（95%置信区间：0.87~0.89）、正常睡眠组0.90（95%置信区间：0.90~0.91）、长睡眠组0.89（95%置信区间：0.87~0.91）（p=0.01）。<b><i>结论：</i></b> 在慢性阻塞性肺疾病患者中，睡眠时长与全因死亡率无显著关联，但短睡眠时长与较差的健康相关生活质量显著相关。