Srimurugan Pratheep Neeraja, Madeleine Pascal, Arendt-Nielsen Lars
Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, School of Medicine, Aalborg University, Aalborg, Denmark.
Centre for Clinical and Basic Research, CCBR, Aalborg, Denmark.
Scand J Pain. 2018 Apr 25;18(2):229-236. doi: 10.1515/sjpain-2018-0017.
Pressure pain threshold (PPT) and PPT maps are commonly used to quantify and visualize mechanical pain sensitivity. Although PPT's have frequently been reported from patients with knee osteoarthritis (KOA), the absolute and relative reliability of PPT assessments remain to be determined. Thus, the purpose of this study was to evaluate the test-retest relative and absolute reliability of PPT in KOA. For that purpose, intra- and interclass correlation coefficient (ICC) as well as the standard error of measurement (SEM) and the minimal detectable change (MDC) values within eight anatomical locations covering the most painful knee of KOA patients was measured.
Twenty KOA patients participated in two sessions with a period of 2 weeks±3 days apart. PPT's were assessed over eight anatomical locations covering the knee and two remote locations over tibialis anterior and brachioradialis. The patients rated their maximum pain intensity during the past 24 h and prior to the recordings on a visual analog scale (VAS), and completed The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and PainDetect surveys. The ICC, SEM and MDC between the sessions were assessed. The ICC for the individual variability was expressed with coefficient of variance (CV). Bland-Altman plots were used to assess potential bias in the dataset.
The ICC ranged from 0.85 to 0.96 for all the anatomical locations which is considered "almost perfect". CV was lowest in session 1 and ranged from 44.2 to 57.6%. SEM for comparison ranged between 34 and 71 kPa and MDC ranged between 93 and 197 kPa with a mean PPT ranged from 273.5 to 367.7 kPa in session 1 and 268.1-331.3 kPa in session 2. The analysis of Bland-Altman plot showed no systematic bias. PPT maps showed that the patients had lower thresholds in session 2, but no significant difference was observed for the comparison between the sessions for PPT or VAS. No correlations were seen between PainDetect and PPT and PainDetect and WOMAC.
Almost perfect relative and absolute reliabilities were found for the assessment of PPT's for KOA patients.
The present investigation implicates that PPT's is reliable for assessing pain sensitivity and sensitization in KOA patients.
压力疼痛阈值（PPT）和PPT图谱常用于量化和可视化机械性疼痛敏感性。虽然已有很多关于膝骨关节炎（KOA）患者PPT的报道，但PPT评估的绝对可靠性和相对可靠性仍有待确定。因此，本研究的目的是评估KOA患者PPT重测的相对可靠性和绝对可靠性。为此，测量了覆盖KOA患者最疼痛膝关节的八个解剖位置的组内和组间相关系数（ICC）以及测量标准误（SEM）和最小可检测变化（MDC）值。
20名KOA患者参加了两次评估，两次评估间隔2周±3天。在覆盖膝关节的八个解剖位置以及胫骨前肌和肱桡肌的两个远端位置评估PPT。患者使用视觉模拟量表（VAS）对过去24小时内以及记录前的最大疼痛强度进行评分，并完成西安大略和麦克马斯特大学骨关节炎指数（WOMAC）和疼痛检测调查。评估两次评估之间的ICC、SEM和MDC。个体变异性的ICC用变异系数（CV）表示。采用Bland-Altman图评估数据集中的潜在偏差。
所有解剖位置的ICC范围为0.85至0.96，被认为“几乎完美”。CV在第一次评估中最低，范围为44.2%至57.6%。比较的SEM范围在34至71 kPa之间，MDC范围在93至197 kPa之间，第一次评估中的平均PPT范围为273.5至367.7 kPa，第二次评估中的平均PPT范围为268.1至331.3 kPa。Bland-Altman图分析显示无系统偏差。PPT图谱显示患者在第二次评估中的阈值较低，但两次评估之间的PPT或VAS比较未观察到显著差异。疼痛检测与PPT以及疼痛检测与WOMAC之间未发现相关性。
发现KOA患者PPT评估具有几乎完美的相对可靠性和绝对可靠性。
本研究表明PPT在评估KOA患者的疼痛敏感性和致敏性方面是可靠的。
