Exploratory examination of the scale structure of the Moorong Self-Efficacy Scale: Application of Rasch Measurement Theory

Exploratory application of the Rasch Measurement (RM) Model for evidence for reproducibility, conceptual/content validity, and structural validity of the Moorong Self-Efficacy Scale (MSES). Secondary RM analysis of data collected in a randomized controlled trial comparing two exercise interventions for persons living with spinal cord injury (SCI). Community-dwelling persons living with SCI enrolled in an exercise study. Adults (<i>n</i> = 79) enrolled in the parent study had a traumatic SCI &gt; 3 months prior, injury level C5 to T12. Not applicable. The original MSES is a 16-item measure of self-efficacy with a 7-level response scale for un/certainty which was developed for use with persons living with SCI. We addressed item misfit, infrequent category endorsement, and category step disorder by removing two items and reorganizing the rating scale. Rating scale changes removed category 4 (Neutral), combined categories 1–3 (Very Uncertain, Somewhat Uncertain, and Uncertain) for all items, and further combined certainty categories for two items. Principal components analysis of the residuals indicated a possible second dimension with a first-contrast Eigenvalue of 2.4. However, the contrasted item groups had explained variance &lt;10% and a dis-attenuated correlation = 0.92 indicating they measure the same underlying trait. The small sample size precluded examination of differential item functioning. Exploratory RM analysis of MSES produced a 14-item Rasch version which identified structural and content validity evidence concerns inherent in the original MSES. However, results could be biased by a small sample size and further study should examine the item content and rating scale structure with larger, more diverse samples of persons living with SCI.

本研究将拉希特测量（Rasch Measurement, RM）模型探索性应用于莫朗自我效能量表（Moorong Self-Efficacy Scale, MSES）的可重复性、概念/内容效度及结构效度验证。本研究为二次拉希特测量分析，数据来自一项针对脊髓损伤（spinal cord injury, SCI）人群的两种运动干预方案的随机对照试验。研究对象为社区居住的脊髓损伤人群，纳入母研究的成年受试者（n=79）均为创伤性脊髓损伤且受伤时间超过3个月，损伤节段为C5至T12。不适用。原版MSES为包含16个条目、采用7级不确定/确定性反应量表的自我效能量表，专为脊髓损伤人群开发。针对条目拟合不良、类别应答频数偏低及类别阶序失调问题，本研究剔除2个条目并重构了评分量表。评分量表调整包括移除第4类（中性），将所有条目的1-3类（极不确定、有些不确定、不确定）合并，并对2个条目进一步合并确定性类别。残差主成分分析显示存在潜在第二维度，第一对比特征值为2.4。但对比组条目组的解释方差占比<10%，且衰减校正相关系数为0.92，表明二者测量的是同一潜在特质。样本量较小，无法开展差异项目功能检验。针对MSES的探索性拉希特测量分析生成了包含14个条目的拉希特版量表，发现原版MSES存在固有结构效度与内容效度相关问题。但研究结果可能因样本量偏小而存在偏倚，后续研究应采用规模更大、异质性更强的脊髓损伤人群样本，对条目内容与评分量表结构展开进一步验证。