Validation of the Pelvic Floor Distress Inventory (PFDI-20) and Pelvic Floor Impact Questionnaire (PFIQ-7) in a Dutch population.
OBJECTIVE
The objective of this study was to validate the Pelvic Floor Distress Inventory (PFDI-20) and Pelvic Floor Impact Questionnaire (PFIQ-7) in Dutch women.


METHODS
Patients with pelvic floor dysfunction completed the Dutch questionnaires at (1) inclusion to evaluate internal consistency, (2) 1 week later to assess test-retest reliability, and (3) 6 months later to assess responsiveness and interpretability of change. To assess validity, floor and ceiling effects and construct validity were tested. A population-based sample (reference group) completed the questionnaires once.


RESULTS
Data of 111 patients and 283 reference group participants were analyzed. Internal consistency of baseline scores in patient and reference groups was moderate (Cronbach's alpha 0.52-0.60) to adequate in the PFDI-20 (Cronbach's alpha 0.71-0.84) and adequate in the PFIQ-7 (Cronbach's alpha 0.88-0.94). Both measures presented adequate test-retest reliability (intraclass correlation coefficient 0.79-0.91) and adequate responsiveness (area under the receiver-operating characteristic curve both 0.77). Interpretability was adequate for PFDI-20 and acceptable for PFIQ-7 with a clinically relevant minimally important change of -23 and -29 points, respectively. At baseline, the scales of the PFIQ-7 showed floor effects (44-55 %) in patients, though the PFIQ-7 summary score did not. No ceiling effects were observed. Construct validity was adequate with all predefined hypotheses confirmed regarding subgroup discrimination using pooled patient and reference group baseline data.


CONCLUSIONS
For assessing distress and health-related quality of life of pelvic floor dysfunction, the Dutch PFDI-20 and PFIQ-7 are reliable and valid in the general Dutch population, and also responsive and interpretable among tertiary care-seeking women.
Department of Urology, Erasmus Medical Center, Room Na-1708, PO Box 2040, 3000 CA, Rotterdam, the Netherlands, e.utomo@erasmusmc.nl.
Elaine
E
Utomo
Bertil F
BF
Blok
Anneke B
AB
Steensma
Ida J
IJ
Korfage
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D009426:Netherlands; D059952:Pelvic Floor Disorders / Q000175:diagnosis* / Q000523:psychology; D011594:Psychometrics; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires