Ekström Magnus, Li Pei Zhi, Lewthwaite Hayley, Bourbeau Jean, Tan Wan C, Jensen Dennis
Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Respiratory Medicine, Allergology and Palliative Medicine, Lund, Sweden.
Montreal Chest Institute, McGill University Health Center Research Institute, McGill University, Montréal, QC, Canada.
ERJ Open Res. 2023 Sep 25;9(5). doi: 10.1183/23120541.00281-2023. eCollection 2023 Sep.
The 6-min walk test (6MWT) is widely used to assess exercise capacity across chronic health conditions, but is currently not useful to assess symptoms, as the scores do not account for the 6-min walk distance (6MWD). We aimed to 1) develop normative reference equations for breathlessness and leg discomfort intensity expressed as modified Borg (mBorg)/6MWD ratios; and 2) validate the equations in people with COPD.
Analysis of people aged ≥40 years who performed two 6MWTs (on a 20-m course) in the Canadian Cohort Obstructive Lung Disease (CanCOLD) study: a healthy cohort (n=291; mean±sd age 67.5±9.4 years; 54% male) with normal 6MWD and lung function, and a COPD cohort (n=156; age 66.2±9.0 years; 56% male; forced expiratory volume in 1 s (FEV)/forced vital capacity 56.6±8.2%; FEV 74.4±18.6% pred). The mBorg score was calculated as the Borg 0-10 category ratio intensity rating of breathlessness or leg discomfort recorded at the end of the 6MWT +1 (range 1-11), to avoid zeros and yield ratios proportional to the symptom score and 6MWD-1.
Using data from the healthy cohort, sex-specific normative reference equations for breathlessness and leg discomfort mBorg/6MWD ratios were developed using multivariable linear regression, accounting for age, and body mass or body mass index. In the COPD cohort, abnormal breathlessness and leg discomfort (mBorg/6MWD>upper limit of normal) showed strong concurrent validity with worse airflow limitation, Medical Research Council breathlessness and COPD Assessment Test scores.
Normative references for the mBorg/6MWD ratio are presented to assess breathlessness and leg discomfort responses to the 6MWT in COPD.
6分钟步行试验（6MWT）被广泛用于评估慢性健康状况下的运动能力，但目前对评估症状并无帮助，因为其分数未考虑6分钟步行距离（6MWD）。我们旨在：1）制定以改良Borg（mBorg）/6MWD比值表示的呼吸困难和腿部不适强度的规范参考方程；2）在慢性阻塞性肺疾病（COPD）患者中验证这些方程。
对加拿大阻塞性肺病队列（CanCOLD）研究中年龄≥40岁且进行了两次6MWT（在20米跑道上）的人群进行分析：一个健康队列（n = 291；平均±标准差年龄67.5±9.4岁；54%为男性），其6MWD和肺功能正常，以及一个COPD队列（n = 156；年龄66.2±9.0岁；56%为男性；1秒用力呼气容积（FEV）/用力肺活量56.6±8.2%；FEV为预计值的74.4±18.6%）。mBorg分数计算为6MWT结束时记录的呼吸困难或腿部不适的Borg 0 - 10级类别比值强度评分 + 1（范围1 - 11），以避免出现零值，并产生与症状评分和6MWD - 1成比例的比值。
利用健康队列的数据，通过多变量线性回归，考虑年龄、体重或体重指数，制定了针对呼吸困难和腿部不适mBorg/6MWD比值的性别特异性规范参考方程。在COPD队列中，异常的呼吸困难和腿部不适（mBorg/6MWD > 正常上限）与更差的气流受限、医学研究委员会呼吸困难评分和慢性阻塞性肺疾病评估测试分数具有很强的同时效度。
给出了mBorg/6MWD比值的规范参考值，以评估慢性阻塞性肺疾病患者对6MWT的呼吸困难和腿部不适反应。
