The process of pain recovery varies and can include the recovery, maintenance, or worsening of symptoms. Many cases of patients with pain show a tendency of recovering as predicted; however, some do not. The characteristics of cases that do not fit the prediction of pain recovery remain unclear. We performed cluster and decision tree analyses to reveal the characteristics in cases that do not fit the prediction of pain recovery. A total of 43 patients with musculoskeletal pain (nonoperative: 22 patients, operative: 13 patients) and central pain (brain disease: 5 patients, spinal cord disease: 3 patients) were included in this longitudinal study. Central sensitivity syndrome (CSS) outcome measures (Central Sensitisation Inventory), pain intensity-related outcome measures (Short-Form McGill Pain Questionnaire-2 (SFMPQ-2)), and cognitive-emotional outcome measures (Hospital Anxiety and Depression Scale and Pain Catastrophising Scale-4) of all patients were assessed at baseline and after 1-2 months. Regression analysis was used to calculate pain recovery prediction values. A hierarchical cluster analysis based on the predicted change of SFMPQ-2 and the observed change of SFMPQ-2 was used to extract subgroups that fit and those that do not fit pain recovery prediction. To extract the characteristics of subgroups that do not fit the prediction of pain recovery, a decision tree analysis was performed. The level of significance was set at 5%. In the results of cluster analysis, patients were classified into three subgroups. Cluster 1 was characterised by worse pain intensity from baseline, cluster 2 by pain, having recovered less and mildly than the predicted value, and Cluster 3 by a marked recovery of pain. In the results of the decision tree analysis, the CSI change was extracted as an indicator related to the classification of all clusters. Our findings suggest that the poor improvement of CSS is characteristic in cases that do not fit the prediction of pain recovery.

中文翻译：

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中枢敏感性与疼痛恢复不佳有关：预测，聚类和决策树分析

疼痛恢复的过程各不相同，可能包括症状的恢复，维持或恶化。许多疼痛患者表现出了如预期般康复的趋势。但是，有些则不然。尚不符合疼痛恢复预测的病例特征尚不清楚。我们进行了聚类和决策树分析，以揭示与疼痛恢复预测不符的病例的特征。这项纵向研究共纳入了43例肌肉骨骼疼痛（非手术：22例，手术：13例）和中枢疼痛（脑部疾病：5例，脊髓疾病：3例）。中枢敏感性综合症（CSS）结局指标（Central Sensitization Inventory），疼痛强度相关结局指标（Short-form McGill Pain Questionnaire-2（SFMPQ-2）），在基线和1-2个月后评估所有患者的认知和情绪结局指标（医院焦虑和抑郁量表和疼痛灾难性量表-4）。回归分析用于计算疼痛恢复预测值。使用基于预测的SFMPQ-2变化和观察到的SFMPQ-2变化的层次聚类分析，提取适合和不适合疼痛恢复预测的亚组。为了提取不适合疼痛恢复预测的亚组特征，进行了决策树分析。显着性水平设定为5％。在聚类分析的结果中，将患者分为三个亚组。第1组的特征是从基线开始的疼痛强度较差，第2组的疼痛是由于疼痛，其恢复程度比预期值要轻和缓，疼痛明显恢复的群集3。在决策树分析的结果中，CSI变化被提取为与所有聚类分类相关的指标。我们的发现表明，在不符合疼痛恢复预测的情况下，CSS的不良改善是其特征。