Lee Jin Hwa, Rhee Chin Kook, Kim Kyungjoo, Kim Jee-Ae, Kim Sang Hyun, Yoo Kwang Ha, Kim Woo Jin, Park Yong Bum, Park Hye Yun, Jung Ki-Suck
Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, EwhaWomans University.
Department of Internal Medicine, Seoul St Mary's Hospital, The Catholic University of Korea, Seoul.
Int J Chron Obstruct Pulmon Dis. 2017 Apr 12;12:1135-1144. doi: 10.2147/COPD.S130140. eCollection 2017.
The purpose of this study was to identify subtypes in patients with mild-to-moderate airflow limitation and to appreciate their clinical and socioeconomic implications.
Subjects who were aged ≥20 years and had forced expiratory volume in 1 second (FEV) ≥60% predicted and FEV/forced vital capacity <0.7 were selected from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) in 2007-2012. The data were merged to the National Health Insurance reimbursement database during the same period. k-Means clustering was performed to explore subtypes. For clustering analysis, six key input variables - age, body mass index (BMI), FEV% predicted, the presence or absence of self-reported wheezing, smoking status, and pack-years of smoking - were selected.
Among a total of 2,140 subjects, five groups were identified through k-means clustering, namely putative "near-normal (n=232)," "asthmatic (n=392)," "chronic obstructive pulmonary disease (COPD) (n=37)," "asthmatic-overlap (n=893)," and "COPD-overlap (n=586)" subtypes. Near-normal group showed the oldest mean age (72±7 years) and highest FEV (102%±8% predicted), and asthmatic group was the youngest (46±9 years). COPD and COPD-overlap groups were male predominant and all current or ex-smokers. While asthmatic group had the lowest prescription rate despite the highest proportion of self-reported wheezing, COPD, asthmatic-overlap, and COPD-overlap groups showed high prescription rate of respiratory medicine. Although COPD group formed only 1.7% of total subjects, they showed the highest mean medical cost and health care utilization, comprising 5.3% of the total medical cost. When calculating a ratio of total medical expense to household income, the mean ratio was highest in the COPD group.
Clinical and epidemiological heterogeneities of subjects with mild-to-moderate airflow limitation and a different level of health care utilization by each subtype are shown. Identification of a subtype with high health care demand could be a priority for effective utilization of limited resources.
本研究旨在识别轻至中度气流受限患者的亚型，并了解其临床和社会经济意义。
从2007 - 2012年第四次韩国国家健康与营养检查调查（KNHANES）中选取年龄≥20岁、一秒用力呼气容积（FEV）≥预测值的60%且FEV/用力肺活量<0.7的受试者。将这些数据与同期的国民健康保险报销数据库合并。采用k均值聚类法探索亚型。为进行聚类分析，选取了六个关键输入变量——年龄、体重指数（BMI）、FEV%预测值、自我报告的喘息情况、吸烟状况以及吸烟包年数。
在总共2140名受试者中，通过k均值聚类确定了五组，即假定的“接近正常（n = 232）”、“哮喘型（n = 392）”、“慢性阻塞性肺疾病（COPD）型（n = 37）”、“哮喘重叠型（n = 893）”和“COPD重叠型（n = 586）”亚型。接近正常组的平均年龄最大（72±7岁）且FEV最高（102%±8%预测值），哮喘型组最年轻（46±9岁）。COPD组和COPD重叠型组以男性为主，均为当前吸烟者或既往吸烟者。尽管哮喘型组自我报告喘息的比例最高，但其处方率最低，而COPD组、哮喘重叠型组和COPD重叠型组的呼吸内科药物处方率较高。尽管COPD组仅占总受试者的1.7%，但其平均医疗费用和医疗保健利用率最高，占总医疗费用的5.3%。在计算总医疗费用与家庭收入的比率时，COPD组的平均比率最高。
显示了轻至中度气流受限受试者的临床和流行病学异质性以及各亚型不同水平的医疗保健利用率。识别出医疗保健需求高的亚型可能是有效利用有限资源的优先事项。
