School of Kinesiology, University of Western Ontario, London, Ontario, Canada (Mr Faricier, Ms Keltz, and Dr Keir); Lawson Health Research Institute, London, Ontario, Canada (Messrs Faricier and Hartley, Ms Keltz, and Drs Suskin, Prior, and Keir); Cardiac Rehabilitation and Secondary Prevention Program, St Joseph's Health Care, London, Ontario, Canada (Mr Hartley and Drs McKelvie, Suskin, and Prior); Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada (Drs McKelvie and Suskin); and Toronto General Hospital Research Institute, Toronto, Ontario, Canada (Dr Keir).
J Cardiopulm Rehabil Prev. 2024 Mar 1;44(2):121-130. doi: 10.1097/HCR.0000000000000837. Epub 2023 Dec 8.
Improving aerobic fitness through exercise training is recommended for the treatment of cardiovascular disease (CVD). However, strong justifications for the criteria of assessing improvement in key parameters of aerobic function including estimated lactate threshold (θ LT ), respiratory compensation point (RCP), and peak oxygen uptake (V˙ o2peak ) at the individual level are not established. We applied reliable change index (RCI) statistics to determine minimal meaningful change (MMC RCI ) cutoffs of θ LT , RCP, and V˙ o2peak for individual patients with CVD.
Sixty-six stable patients post-cardiac event performed three exhaustive treadmill-based incremental exercise tests (modified Bruce) ∼1 wk apart (T1-T3). Breath-by-breath gas exchange and ventilatory variables were measured by metabolic cart and used to identify θ LT , RCP, and V˙ o2peak . Using test-retest reliability and mean difference scores to estimate error and test practice/exposure, respectively, MMC RCI values were calculated for V˙ o2 (mL·min -1. kg -1 ) at θ LT , RCP, and V˙ o2peak .
There were no significant between-trial differences in V˙ o2 at θ LT ( P = .78), RCP ( P = .08), or V˙ o2peak ( P = .74) and each variable exhibited excellent test-retest variability (intraclass correlation: 0.97, 0.98, and 0.99; coefficient of variation: 6.5, 5.4, and 4.9% for θ LT , RCP, and V˙ o2peak , respectively). Derived from comparing T1-T2, T1-T3, and T2-T3, the MMC RCI for θ LT were 3.91, 3.56, and 2.64 mL·min -1. kg -1 ; 4.01, 2.80, and 2.79 mL·min -1. kg -1 for RCP; and 3.61, 3.83, and 2.81 mL·min -1. kg -1 for V˙ o2peak . For each variable, MMC RCI scores were lowest for T2-T3 comparisons.
These MMC RCI scores may be used to establish cutoff criteria for determining meaningful changes for interventions designed to improve aerobic function in individuals with CVD.
运动训练提高有氧运动能力被推荐用于心血管疾病（CVD）的治疗。然而，对于评估有氧功能关键参数（包括估计的乳酸阈（θ LT ）、呼吸补偿点（RCP）和峰值摄氧量（V˙ o2peak ））的个体水平改善的标准，尚无强有力的依据。我们应用可靠变化指数（RCI）统计来确定 CVD 个体患者的θ LT 、RCP 和 V˙ o2peak 的最小有意义变化（MMC RCI ）截断值。
66 例心脏事件后稳定患者在 1 周内进行了 3 次完全跑步机递增运动测试（改良 Bruce）（T1-T3）。通过代谢箱测量逐口气体交换和通气变量，并用于确定θ LT 、RCP 和 V˙ o2peak 。使用测试-再测试可靠性和平均差异分数分别估计误差和测试实践/暴露，计算了θ LT 、RCP 和 V˙ o2peak 处 V˙ o2（mL·min -1. kg -1 ）的 MMC RCI 值。
在θ LT （P =.78）、RCP （P =.08）或 V˙ o2peak （P =.74）方面，各试验之间没有显著差异，并且每个变量都表现出极好的测试-再测试可变性（组内相关系数：0.97、0.98 和 0.99；变异系数：6.5%、5.4%和 4.9%，分别用于θ LT 、RCP 和 V˙ o2peak ）。从 T1-T2、T1-T3 和 T2-T3 比较中得出，θ LT 的 MMC RCI 分别为 3.91、3.56 和 2.64 mL·min -1. kg -1 ；RCP 为 4.01、2.80 和 2.79 mL·min -1. kg -1 ；V˙ o2peak 为 3.61、3.83 和 2.81 mL·min -1. kg -1 。对于每个变量，T2-T3 比较的 MMC RCI 得分最低。
这些 MMC RCI 评分可用于为旨在提高 CVD 个体有氧运动能力的干预措施确定有意义变化的判定标准。
