The psychometric properties of the PRAFAB-questionnaire: a brief assessment questionnaire to evaluate severity of urinary incontinence in women.

Aims: To determine the psychometric properties of the (5-item) total PRAFAB-questionnaire score in a group of patients with stress or predominant urgency urinary incontinence (UI) to justify its use in clinical practice and research.

Methods: Psychometric properties were assessed in a prospective cohort of patients with primary or recurrent UI referred for physiotherapy treatment.

Results: In total, 99 women enrolled the cohort study, of whom 87 were classified as stable ("about the same" on the global rating scale [GRS]) and included for analyses. Factor analysis resulted in a single underlying factor in both UI groups. The PRAFAB-questionnaire scores demonstrated excellent test-retest reliability (high ICCsagreement [0.93-0.95] and kappa scores for individual items) and excellent internal consistency (Cronbach's alpha's of 0.82). The PRAFAB-questionnaire was able to discriminate among different patient groups indicating good construct validity. Responsiveness to clinical improvement for both groups was shown to be excellent with large effect size statistics and high correlations (0.79-0.89) with patients' perceived benefit on the GRS indicating excellent longitudinal validity. The minimally important change stratified for non-severe and severe classified patients were estimated between -2.5 to -4.6 and -4.5 to -7.0 points, respectively for the stress UI group and -2.5 to -3.4 points and -4.0 to -4.4, respectively for the urgency UI group.

Conclusions: The brief and simple PRAFAB-questionnaire demonstrated good psychometric properties for use in clinical practice and research to evaluate treatment effects for UI in women. Future research will be necessary to replicate these findings and further explore its psychometric properties.