Impellizzeri Franco M, Leunig Michael, Preiss Stefan, Guggi Thomas, Mannion Anne F
Research & Development Department, Schulthess Clinic, Lengghalde 2, 8008 Zurich, Switzerland.
Department of Orthopaedic Surgery, Schulthess Clinic, Lengghalde 2, 8008 Zurich, Switzerland.
Knee. 2017 Mar;24(2):372-379. doi: 10.1016/j.knee.2016.11.016. Epub 2016 Dec 13.
The Core Outcome Measure Index (COMI) is a very short outcome instrument used in spine patients. The aim of this study was to examine the utility of a knee version of the COMI in patients undergoing total knee arthroplasty (TKA) by assessing the reproducibility, construct and discriminant validity, and responsiveness.
Preoperatively, 224 patients completed the Oxford Knee Score (OKS), EuroQoL (EQ-5D) and the COMI-Knee; 189 (84) % also completed the questionnaires at follow-up and 73 patients completed preoperatively the COMI-knee twice.
The weighted kappa values for the COMI-knee single items ranged from 0.80 to 0.89 and the ICC for the COMI-knee (composite score), 0.86. The absolute SEM for COMI-knee was 0.4 points, i.e. four percent of the maximum value (10 points) and six percent of the average value (6.6 points). The Area Under the Curve derived from the Receiver Operating Characteristic method for the COMI-knee was 0.97 (95% CI, 0.93 to 0.99), with a cut-off value for indicating a "good" result of 2.3 (100% specificity, 87% sensitivity). Correlations between the COMI-knee and the OKS were -0.72 at baseline and -0.87 at six months. The correlations between the change scores for the COMI-knee and the change scores for the OKS and EQ5D index were 0.77 and 0.69, respectively.
The measurement properties of the COMI-knee satisfy international quality criteria and hence support its use in assessing patients undergoing TKA.
核心结局指标指数（COMI）是一种用于脊柱疾病患者的非常简短的结局评估工具。本研究的目的是通过评估其再现性、结构效度、区分效度和反应度，来检验膝关节版COMI在接受全膝关节置换术（TKA）患者中的实用性。
术前，224例患者完成了牛津膝关节评分（OKS）、欧洲五维度健康量表（EQ-5D）和膝关节版COMI；189例（84%）患者在随访时也完成了这些问卷，73例患者术前两次完成膝关节版COMI。
膝关节版COMI单项的加权kappa值范围为0.80至0.89，膝关节版COMI（综合评分）的组内相关系数为0.86。膝关节版COMI的绝对测量标准误为0.4分，即最大值（10分）的4%，平均值（6.6分）的6%。采用受试者工作特征法得出的膝关节版COMI曲线下面积为0.97（95%可信区间，0.93至0.99），表明“良好”结果的截断值为2.3（特异性100%，敏感性87%）。膝关节版COMI与OKS在基线时的相关性为-0.72，在6个月时为-0.87。膝关节版COMI的变化分数与OKS和EQ5D指数的变化分数之间的相关性分别为0.77和0.69。
膝关节版COMI的测量特性符合国际质量标准，因此支持其用于评估接受TKA的患者。
