Hendriks Erik J M, Bernards Arnold T M, Staal J Bart, de Vet Henrica C W, de Bie Rob A
Department of Epidemiology and Centre for Evidence Based Physiotherapy & Clinical Guidelines (CEBP), Maastricht University, Maastricht, The Netherlands.
BMC Urol. 2008 Jan 24;8:1. doi: 10.1186/1471-2490-8-1.
To investigate the factor structure, dimensionality and construct validity of the (5-item) PRAFAB questionnaire score in women with stress urinary incontinence (stress UI).
A cross validation study design was used in a cohort of 279 patients who were randomly divided into Sample A or B. Sample A was used for preliminary exploratory factor analyses with promax rotation. Sample B provided an independent sample for confirming the premeditated and proposed factor structure and item retention. Internal consistency, item-total and subscale correlations were determined to assess the dimensionality. Construct validity was assessed by comparing factor-based scale means by clinical characteristics based on known relationships.
Factor analyses resulted in a two-factor structure or subscales: items related to 'leakage severity' (protection, amount and frequency) and items related to its 'perceived symptom impact' or consequences of stress UI on the patient's life (adjustment and body (or self) image). The patterns of the factor loadings were fairly identical for both study samples. The two constructed subscales demonstrated adequate internal consistency with Cronbach's alphas in a range of 0.78 and 0.84 respectively. Scale scores differed by clinical characteristics according to the expectations and supported the construct validity of the scales.
The findings suggest a two-factorial structure of the PRAFAB questionnaire. Furthermore the results confirmed the internal consistency and construct validity as demonstrated in our previous study. The best description of the factorial structure of the PRAFAB questionnaire was given by a two-factor solution, measuring the stress UI leakage severity items and the perceived symptom impact items. Future research will be necessary to replicate these findings in different settings, type of UI and non-white women and men.
探讨压力性尿失禁（压力性尿失禁）女性中（5项）PRAFAB问卷评分的因子结构、维度和结构效度。
采用交叉验证研究设计，对279例患者进行队列研究，将其随机分为样本A或样本B。样本A用于采用斜交旋转的初步探索性因子分析。样本B提供一个独立样本，用于确认预先设计和提出的因子结构及项目保留情况。通过确定内部一致性、项目-总分相关性和分量表相关性来评估维度。通过基于已知关系比较基于因子的量表均值与临床特征，评估结构效度。
因子分析得出一个两因子结构或分量表：与“漏尿严重程度”相关的项目（防护、量和频率）以及与其“感知症状影响”或压力性尿失禁对患者生活的后果相关的项目（调整和身体（或自我）形象）。两个研究样本的因子载荷模式相当一致。两个构建的分量表显示出足够的内部一致性，Cronbach's α系数分别在0.78和0.84范围内。量表评分根据预期因临床特征而异，并支持量表的结构效度。
研究结果表明PRAFAB问卷具有两因子结构。此外，结果证实了我们先前研究中所示的内部一致性和结构效度。PRAFAB问卷因子结构的最佳描述是由一个两因子解决方案给出的，该方案测量压力性尿失禁漏尿严重程度项目和感知症状影响项目。未来有必要在不同环境、尿失禁类型以及非白人女性和男性中重复这些发现。
