Escobar A, García Pérez L, Herrera-Espiñeira C, Aizpuru F, Sarasqueta C, Gonzalez Sáenz de Tejada M, Quintana J M, Bilbao A
Research Unit, Hospital Universitario Basurto, Bilbao, Spain.
Research Associate, Red de Investigación en Servicios Sanitarios en Enfermedades Crónicas (REDISSEC), Spain.
J Eval Clin Pract. 2017 Dec;23(6):1232-1239. doi: 10.1111/jep.12765. Epub 2017 May 26.
There is conflicting evidence about what factors influence outcomes after total knee replacement (TKR). The objective is to identify baseline factors that differentiate patients who achieve both, minimal clinically important difference (MCID) and a patient acceptable symptom state (PASS) in pain and function, measured by WOMAC, after TKR from those who do not attain scores above the cutoff in either of these dimensions.
One-year prospective multicentre study. Patients completed WOMAC, SF-12, EQ-5D, expectations, other joint problems and sociodemographic data while in the waiting list, and 1-year post-TKR. Dependent variable was a combination of MCID and PASS in both dimensions (yes/no). Univariate analysis was performed to identify variables associated. Exploratory factor analysis (EFA) was performed to study how these variables grouped into different factors.
Total sample comprised 492 patients. Mean (SD) age was 71.3 (6.9), and there were a 69.7% of women. Of the total, 106 patients did not attain either MCID or PASS in either dimension, and 230 exceeded both thresholds in both dimensions. In the univariate analysis, 13 variables were associated with belonging to one group or another. These 13 variables were included in EFA; 3 factors were extracted: expectations, mental health, and other joints problems. The percentage of variance explained by the 3 factors was 80.4%.
We have found 2 modifiable baseline factors, expectations and mental health, that should be properly managed by different specialist. Indication of TKR should take into account these modifiable factors for improving outcomes after TKR.
关于哪些因素会影响全膝关节置换术（TKR）后的结果，证据存在冲突。目的是确定能区分TKR后在疼痛和功能方面达到最小临床重要差异（MCID）和患者可接受症状状态（PASS）（通过WOMAC测量）的患者与在这两个维度上均未达到临界值以上分数的患者的基线因素。
为期一年的前瞻性多中心研究。患者在等待名单上以及TKR后1年时完成WOMAC、SF-12、EQ-5D、期望、其他关节问题和社会人口统计学数据。因变量是两个维度上MCID和PASS的组合（是/否）。进行单变量分析以确定相关变量。进行探索性因素分析（EFA）以研究这些变量如何分组为不同因素。
总样本包括492名患者。平均（标准差）年龄为71.3（6.9）岁，女性占69.7%。总共有106名患者在任何一个维度上均未达到MCID或PASS，230名患者在两个维度上均超过了两个阈值。在单变量分析中，13个变量与属于哪一组相关。这13个变量被纳入EFA；提取出3个因素：期望、心理健康和其他关节问题。这3个因素解释的方差百分比为80.4%。
我们发现了2个可改变的基线因素，即期望和心理健康，应由不同专科医生进行适当管理。TKR的指征应考虑这些可改变因素以改善TKR后的结果。
