Psychometric equivalence of the OAB-q in Danish, German, Polish, Swedish, and Turkish.
OBJECTIVE
Patient-reported outcomes (PROs) are measures of patients' health status provided directly by patients and when utilized in clinical trials, multiple language versions may be needed. The overactive bladder questionnaire (OAB-q), a self-administered PRO assessing symptom bother and health-related quality of life (HRQL) in patients with OAB, was developed in US English and has been translated into more than 40 languages. This analysis evaluated the psychometric equivalence of five language versions of the OAB-q.


METHODS
The Disease Management Study (DMS) was a multicenter, double-blind, placebo-controlled, parallel group, randomized study in adults with OAB. Participants completed the OAB-q, 3-day micturition diaries, and the patient's perception of bladder condition (PPBC) at baseline and weeks 1 and 12 of treatment.


RESULTS
Data from 398 patients from five countries were analyzed: Denmark (N = 71), Germany (N = 127), Poland (N = 60), Sweden (N = 94), and Turkey (N = 46). Participants were a mean of 57.4 years old; 31% were male; and almost all were Caucasian. Cronbach alphas for the OAB-q symptom bother subscale = 0.71 to 0.83 and 0.82 to 0.94 for the HRQL subscales (concern, coping, sleep, and social) across all five languages. OAB-q subscales were significantly correlated with PPBC in all languages. Mean baseline to week 12 change scores = -21.4 to -30.3 for symptom bother and 5.2 to 36.0 for the HRQL subscales. Effect sizes for the symptom bother subscale = 0.92 to 2.79 and 0.21 to 1.30 for the HRQL subscales.


CONCLUSIONS
OAB-q language versions of Danish, German, Polish, Swedish, and Turkish demonstrated acceptable psychometric characteristics, including internal consistency reliability, construct validity, and responsiveness.
Coyne
Karin S
KS
United BioSource Corporation, Center for Health Outcomes Research, Bethesda, MD 20814, USA. Karin.Coyne@unitedbiosource.com
Margolis
Mary Kay
MK
Thompson
Chris
C
Kopp
Zoe
Z
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003431:Cross-Cultural Comparison; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D012720:Severity of Illness Index; D014421:Turkey; D053201:Urinary Bladder, Overactive / Q000175:diagnosis*