Núcleo de Assistência, Ensino e Pesquisa em Reabilitação Pulmonar (NuReab), Centro de Ciências da Saúde e do Esporte (CEFID), Universidade do Estado de Santa Catarina (UDESC), Florianópolis, Santa Catarina, Brazil.
Programa de Pós-Graduação em Ciências do Movimento Humano, Santa Catarina, Brazil.
Respir Care. 2021 Dec;66(12):1876-1884. doi: 10.4187/respcare.08889. Epub 2021 Oct 20.
The modified Medical Research Council (mMRC) and COPD Assessment Test (CAT) are assessment instruments associated with level of physical activity of daily living (PADL) in patients with COPD. This study aimed to identify mMRC and CAT cutoff points to discriminate sedentary behavior and PADL level of subjects with COPD and verify whether these cutoff points differentiate pulmonary function, health-related quality of life (HRQOL), functional status, and mortality index in subjects with COPD.
Subjects ( 131, FEV: 36.7 ± 16.1% predicted) were assessed for lung function, mMRC, CAT, HRQOL, functional status, and mortality index. PADL was monitored using a triaxial accelerometer, and subjects were classified as sedentary/nonsedentary (cutoff point of 8.5 h/d in PADL < 1.5 metabolic equivalent of task [MET]), physically active/inactive (cutoff point of 80 min/d in PADL ≥ 3 METs), and with/without severe physical inactivity (cutoff point of 4,580 steps/d), according to variables provided by accelerometer.
ROC curve indicated mMRC cutoff point of ≥ 2 ( < .05) for physical inactivity (sensitivity = 66%, specificity = 56%, AUC = 0.62), severe physical inactivity (sensitivity = 81%, specificity = 66%, AUC = 0.76), and sedentary behavior (sensitivity = 61%, specificity = 70%, AUC = 0.65). The identified CAT cutoff points were ≥ 16 and ≥ 20, considering severe physical inactivity (sensitivity = 76%, specificity = 54%, AUC = 0.69, < .001) and sedentary behavior (sensitivity = 51%, specificity = 90%, AUC = 0.71, = .001), respectively. Subjects who had mMRC ≥ 2 and CAT ≥ 16 or ≥ 20 presented worse pulmonary function, HRQOL, functional status, and mortality index compared with those who scored mMRC < 2 and CAT <16 or < 20.
mMRC cutoff point of ≥ 2 is recommended to discriminate PADL level and sedentary behavior, whereas CAT cutoff points of ≥ 16 and ≥ 20 discriminated severe physical inactivity and sedentary behavior, respectively. These cutoff points differentiated subjects with COPD regarding all the outcomes assessed in this study.
改良版医学研究理事会呼吸困难量表（mMRC）和 COPD 评估测试（CAT）是与 COPD 患者日常生活体力活动（PADL）水平相关的评估工具。本研究旨在确定 mMRC 和 CAT 切点，以区分 COPD 患者的久坐行为和 PADL 水平，并验证这些切点是否能区分 COPD 患者的肺功能、健康相关生活质量（HRQOL）、功能状态和死亡率指数。
对 131 名受试者（FEV：36.7 ± 16.1%预计值）进行肺功能、mMRC、CAT、HRQOL、功能状态和死亡率指数评估。使用三轴加速度计监测 PADL，根据加速度计提供的变量，将受试者分为久坐/非久坐（PADL<1.5 代谢当量任务[MET]的 8.5 小时/天的切点）、体力活动/不活动（PADL≥3 METs 的 80 分钟/天的切点）和有/无严重体力不活动（PADL<4,580 步/天的 4,580 步/天的切点）。
ROC 曲线表明，mMRC 切点≥2（<0.05）可用于区分体力不活动（敏感性=66%，特异性=56%，AUC=0.62）、严重体力不活动（敏感性=81%，特异性=66%，AUC=0.76）和久坐行为（敏感性=61%，特异性=70%，AUC=0.65）。确定的 CAT 切点分别为≥16 和≥20，考虑到严重体力不活动（敏感性=76%，特异性=54%，AUC=0.69，<0.001）和久坐行为（敏感性=51%，特异性=90%，AUC=0.71，<0.001）。与 mMRC<2 和 CAT<16 或<20 的受试者相比，mMRC≥2 和 CAT≥16 或≥20 的受试者的肺功能、HRQOL、功能状态和死亡率指数更差。
建议使用 mMRC 切点≥2 来区分 PADL 水平和久坐行为，而 CAT 切点≥16 和≥20 分别区分严重体力不活动和久坐行为。这些切点可区分 COPD 患者的所有研究结果。
