Validation of the Pelvic Floor Inventories Leiden (PelFIs) in English.

AIMS: To evaluate the validity and reliability of the English translation of an interviewer-administered pelvic floor questionnaire, the "Pelvic Floor Inventories Leiden" (PeLFIs) for women, which addresses complaints of prolapse, bladder, and bowel dysfunction, pelvic floor pain and/or sexual dysfunction related to pelvic floor dysfunction. METHODS: The formal forward-backward translation of the PeLFIs was performed by bilingual Dutch/English translators. The final English version was administered to healthy volunteers (N = 94) and patients (N = 180) in Canada and the United States. Psychometric properties of the English version were examined, including internal consistency, test-retest reliability, content, and construct validity. Internal consistency was measured using Cronbach's alpha. Test-retest reliability was assessed by intraclass correlation coefficients. Construct validity was established by comparing scores in healthy volunteers and patients (using t-tests) and by intercorrelating domains. RESULTS: The forward-backward translation of the English version of the PeLFIs was consistent with the original Dutch questionnaire. In total, 274 questionnaires were administered. The retest was administered 2 weeks after the initial PeLFIs interview. Internal consistency of the questionnaire was 0.88 for the total scale. Cronbach's alpha of the domains ranged from 0.71 to 0.95. For the test-retest reliability, the agreement rate between the two tests exceeded 95% and the intraclass correlation ranged from 0.6 to 0.8. The differences between healthy volunteers and patients were statistically significant for all domains, but did not exceed the minimal important difference for some domains. Correlations between the domains were moderate to high. CONCLUSIONS: The PeLFIs questionnaire has been translated successfully into English and in its evaluation has shown adequate internal consistency and reliability.