Pain catastrophizing: rumination is a discriminating factor among individuals with different pain characteristic

Abstract: The objective of this study was to compare the scores of the Helplessness, Magnification, Rumination, and Catastrophizing factors of the Pain Catastrophizing Scale (PCS) between samples with different pain characteristics. The psychometric properties of the PCS were evaluated in 1,151 Brazilian adults (78.9% female; 38.6 (SD = 10.8) years): 335 had no pain, 390 had been in pain for less than 3 months, 250 had been in recurring pain for more than 3 months, and 176 had been in continuous pain for more than 3 months. Confirmatory factor analysis (CFA) was conducted to verify the fit of the PCS models. Convergent validity and reliability were evaluated. Multi-group analysis was used to estimate the invariance of the factorial model. The global score for the PCS factors was obtained using the regression weight matrix for estimating factor scores from CFA. Analysis of variance was used to compare scores between samples. After excluding three items, the tri-factorial model showed adequate fit. The model parameters were invariant (Δχ2(λ,i,β,Res); p≥0.05). Individuals experiencing pain showed higher scores for catastrophic thoughts. Individuals with pain for less than 3 months had the highest scores for Rumination (p < 0.001). The PCS showed valid, reliable, and invariant results for the sample of Brazilian adults in no pain or with different pain conditions. The PCS adequately discriminated individuals in pain from those without pain. Among those in pain, Rumination was the only discriminating factor.

摘要：本研究旨在对比不同疼痛特征人群样本的疼痛灾难化量表（Pain Catastrophizing Scale, PCS）无助感、放大化、反刍思维及灾难化四大因子得分。本研究纳入1151名巴西成年受试者，其中78.9%为女性，年龄38.6岁，标准差（Standard Deviation, SD）=10.8，分为4组：335名无疼痛症状者、390名疼痛病程不足3个月者、250名复发性疼痛且病程超过3个月者，以及176名持续性疼痛且病程超过3个月者。
本研究对PCS的心理测量学属性进行评估：采用验证性因子分析（Confirmatory Factor Analysis, CFA）验证该量表模型的拟合优度，评估其聚合效度与信度；通过多组分析估算因子模型的不变性；采用回归权重矩阵结合验证性因子分析结果计算PCS各因子的总得分；运用方差分析比较不同组间的得分差异。
结果显示，剔除3个条目后，该量表的三维因子模型具备良好的拟合效果，且模型参数满足不变性要求（Δχ²(λ,i,β,Res); p≥0.05）。经历疼痛的个体其灾难化思维得分显著更高；病程不足3个月的疼痛人群反刍思维因子得分最高（p < 0.001）。
本研究表明，针对巴西无痛或存在不同疼痛状况的成年人群，PCS具备可靠的效度、信度与测量不变性，可有效区分疼痛人群与无痛人群；在疼痛人群中，反刍思维是唯一具备区分能力的因子。