O'Connell Megan E, Suskin Neville, Prior Peter L
Department of Psychology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
St Joseph's Hospital Cardiac Rehabilitation & Secondary Prevention Program, London, Ontario, Canada.
CJC Open. 2021 May 16;3(9):1139-1148. doi: 10.1016/j.cjco.2021.05.006. eCollection 2021 Sep.
Mediated by outcomes such as improved exercise capacity, cardiac rehabilitation (CR) reduces morbidity and mortality. For accuracy, an individual CR patient's change must be measured reliably, an issue not typically considered in practice. Drawing from psychometric theory, we calculated reliable change indices (RCIs), to measure CR patients' apart from that from error and test practice/exposure, in exercise capacity, anxiety, and depression.
Indirectly calculated exercise capacity (peak metabolic equivalents [METs]) and psychological symptoms were each measured twice, 1 week apart, by administering treadmill tests or the Hospital Anxiety and Depression Scale (HADS) to separate samples of 35 (mean age: 59.0 years; 6 women) and 96 (mean age: 64.4 years; 32 women) CR patients, respectively. Using test-retest reliability and mean difference scores from these samples to estimate error and practice/exposure effects, we calculated RCIs for a separate cohort (n = 2066; mean age: 62.0 years; 533 women) who completed 6-month CR, and compared change distributions (worsened/unchanged/improved) based on critical RCIs, mean and percent changes, cut-off scores, and standard deviations.
Practice/exposure effects were nonsignificant, except the mean HADS anxiety score decreased significantly ( ≤ 0.013; d = 0.17, small effect). Test-retest reliabilities were high (METs = 0.934; HADS anxiety score = 0.912; HADS depression score = 0.90; < 0.001). Among 2066 CR patients, RCI distributions differed ( < 0.001) from those of most other change criteria.
Change ascertainment depends on criterion choice. A Canadian Cardiovascular Society CR quality indicator of increase by 0.5 MET may be too small to assess individuals' functional capacity change. RCIs offer a pragmatic approach to benchmarking reliable change frequency, and pending further validation, could be used for feedback to individual patients.
通过诸如提高运动能力等结果介导，心脏康复（CR）可降低发病率和死亡率。为了准确起见，必须可靠地测量个体CR患者的变化，而这在实际操作中通常未被考虑。借鉴心理测量理论，我们计算了可靠变化指数（RCI），以测量CR患者在运动能力、焦虑和抑郁方面除误差和测试练习/暴露之外的变化。
通过对35名（平均年龄：59.0岁；6名女性）和96名（平均年龄：64.4岁；32名女性）CR患者的不同样本分别进行跑步机测试或医院焦虑抑郁量表（HADS）测量，间接计算运动能力（峰值代谢当量[METs]）和心理症状，两次测量间隔1周。利用这些样本的重测信度和平均差异分数来估计误差和练习/暴露效应，我们为完成6个月CR的另一个队列（n = 2066；平均年龄：62.0岁；533名女性）计算了RCI，并根据临界RCI、平均和百分比变化、截止分数和标准差比较了变化分布（恶化/不变/改善）。
练习/暴露效应不显著，除了HADS焦虑平均得分显著降低（≤0.013；d = 0.17，小效应）。重测信度较高（METs = 0.934；HADS焦虑得分 = 0.912；HADS抑郁得分 = 0.90；<0.001）。在2066名CR患者中，RCI分布与大多数其他变化标准的分布不同（<0.001）。
变化的确定取决于标准的选择。加拿大心血管学会CR质量指标中增加0.5 MET可能太小，无法评估个体的功能能力变化。RCI提供了一种实用的方法来衡量可靠变化频率，在进一步验证之前，可用于向个体患者提供反馈。
