Medicine School, Universidade Estadual de Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group, Universidade Estadual de Londrina, Londrina, Parana, Brazil.
PLoS One. 2020 Sep 22;15(9):e0239332. doi: 10.1371/journal.pone.0239332. eCollection 2020.
The Low Back Activity Confidence Scale (LoBACS) assesses the self-efficacy to perform activities in individuals with chronic low back pain (CLBP). As self-efficacy appears to directly influence the patient's functional capacity and prognosis, it is important to develop a scale that evaluates this attribute to guide treatment strategy and monitor the clinical course of patients. This study aimed to evaluate the reliability, construct validity, and responsiveness of the Brazilian version of the LoBACS. The scale was applied to 112 male and female patients (age, 18-65 years) with specific and nonspecific CLBP. For evaluating the interobserver reliability, the scale was applied twice on the first evaluation day by two trained evaluators (A and B). Within 48-72 h of the first evaluation, assessor A reapplied the scale to evaluate intraobserver reliability (test-retest), which was analyzed by intraclass correlation coefficient (ICC). The first LoBACS applied in the baseline evaluation was also used to assess the construct validity of the scale by factor analysis. For responsiveness, the scale was applied 5 times at 2-week intervals and the change in scores was analyzed by the repeated measures ANOVA. Although factor analysis indicated three subscales, they did not present acceptable values of convergent and divergent validity. Reliability ranged from good to excellent, with ICC values of .90 (95% CI, .84; .93) and .85 (95% CI, .77; .91) for inter- and intraobserver variability for total score. Moreover, the total score was responsive in all comparisons, with no floor or ceiling effects. Thus, only the total score of the Brazilian version of LoBACS proved to be reliable, valid, and responsive.
下背痛活动信心量表（LoBACS）评估了慢性下背痛（CLBP）患者进行活动的自我效能感。由于自我效能感似乎直接影响患者的功能能力和预后，因此开发一种评估该属性的量表以指导治疗策略并监测患者的临床病程非常重要。本研究旨在评估巴西版 LoBACS 的信度、结构效度和反应度。该量表应用于 112 名有特定和非特异性 CLBP 的男性和女性患者（年龄 18-65 岁）。为了评估观察者间的可靠性，两名经过培训的评估员（A 和 B）在第一次评估的第一天对量表进行了两次评估。在第一次评估后的 48-72 小时内，评估员 A 再次应用量表进行观察者内可靠性（测试-重测）评估，采用组内相关系数（ICC）进行分析。在基线评估中首次应用的 LoBACS 也用于通过因子分析评估量表的结构效度。为了评估反应性，在 2 周间隔的 5 次应用该量表，并通过重复测量方差分析来分析评分变化。尽管因子分析表明存在三个亚量表，但它们并未表现出可接受的收敛和发散效度值。可靠性范围从良好到极好，总分为.90（95%置信区间，.84；.93）和.85（95%置信区间，.77；.91），用于观察者间和观察者内的总评分变异性。此外，总评分在所有比较中均具有反应性，没有地板效应或天花板效应。因此，只有巴西版 LoBACS 的总分被证明是可靠、有效且具有反应性的。
