COMPARATIVE EVALUATION OF THE PSYCHOMETRIC PROPERTIES OF ORTHOPEDIC SCALES FOR LOW BACK PAIN

ABSTRACT Objective: To evaluate the reliability, response capacity and validity of four scales for low back pain and correlate these scales with each other and the Self-Administered Comorbidity Questionnaire (SACQ). Methods: We evaluated the psychometric properties of four previously selected scales for low back pain: the Roland-Morris Disability Questionnaire (RMDQ), the Quebec Back Pain Questionnaire (QBPDS), the Waddell Disability Index (WDI) and the Back Pain Functional Scale (BPFS) and Self-Administered Comorbidity Questionnaire (SACQ) comorbidity scale. Exploratory and confirmatory factor analyses were conducted. Reliability and internal consistency were measured by Cronbach's alpha. Validity was measured through correlation of the scales with the Self-Administered Comorbidity Questionnaire comorbidity scale and an analysis of the structural equations between them. Results: The scales showed adequate indicators based on the factor structure and showed Kaiser-Meyer-Olkin values above 0.90. After the exploratory factor analysis, all scales showed fit indicators suited to a factor model, following the same pattern as the original validations. Similarly, they showed good internal consistency (Cronbach's alpha greater than .78). The only scale that showed factor loadings suggesting the exclusion of any item was the Roland-Morris. In terms of validity, the scales showed positive correlation coefficients similar to the Self-Administered Comorbidity Questionnaire and between them. Conclusion: Regarding the scales evaluated, they showed similar indications of reliability and internal consistency, such that we did not find sufficient evidence to indicate one scale over another. Level of Evidence I; Diagnostic studies – Investigation of a diagnostic test.

摘要
研究目的：评估四种腰痛量表的信度、反应度与效度，并分析这些量表之间以及与自评共病问卷（Self-Administered Comorbidity Questionnaire, SACQ）之间的相关性。
研究方法：本研究对预先选定的四种腰痛量表及自评共病问卷的心理测量学特征进行评估，分别为罗兰-莫里斯残疾问卷（Roland-Morris Disability Questionnaire, RMDQ）、魁北克背痛问卷（Quebec Back Pain Questionnaire, QBPDS）、沃德尔残疾指数（Waddell Disability Index, WDI）以及背痛功能量表（Back Pain Functional Scale, BPFS）。采用探索性因素分析与验证性因素分析开展研究；通过克朗巴赫α系数衡量信度与内部一致性；以各量表与自评共病问卷的相关性及各量表间的结构方程模型分析验证效度。
研究结果：基于因素结构分析，各量表均表现出良好的指标表现，凯泽-迈耶-奥尔金（Kaiser-Meyer-Olkin, KMO）值均高于0.90。经探索性因素分析后，所有量表均符合单因素模型的拟合指标要求，与原始验证的模式一致；同时各量表均表现出良好的内部一致性（克朗巴赫α系数均大于0.78）。仅罗兰-莫里斯残疾问卷的因素载荷提示需剔除其中某一项目。在效度方面，各量表与自评共病问卷及彼此间均呈现出相似的正相关系数。
研究结论：针对本次评估的四种量表，其信度与内部一致性表现相近，未发现足够证据表明某一量表优于其他量表。
证据等级I：诊断性研究——诊断试验调查