Bother and distress associated with Peyronie's disease: validation of the Peyronie's Disease Questionnaire (PDQ)
Hellstrom WJ, Feldman R, Rosen RC, Smith T, Kaufman G, Tursi J.J Urol. 2013 Jan 31. pii: S0022-5347(13)00230-9. doi: 10.1016/j.juro.2013.01.090. [Epub ahead of print]

Source

Department of Urology, Tulane University Health Sciences Center, New Orleans, LA, USA. Electronic address: whellst@tulane.edu.

Abstract

PURPOSE:

To validate the Peyronie's Disease Questionnaire (PDQ), a 15-question self-reported survey, measuring the impact and severity of Peyronie's disease (PD) symptoms in 3 domains: 1) Psychological and Physical Symptoms, 2) Penile Pain, and 3) Symptom Bother.

MATERIALS AND METHODS:

Baseline data from two phase 3 clinical trials of collagenase clostridium histolyticum for the treatment of PD-associated penile curvature and bother were used (N=334; N=345). Collected data included PDQ domain scores (full PDQ available at http://www.auxilium.com/PDQ), International Index of Erectile Function (IIEF) scores, objective measures of penile curvature, and subject-reported PD symptom severity. The Psychometric analyses included confirmatory factor analyses (CFAs), inter-item reliability, and tests of convergent and discriminant validity, all related to the overall construct validity of the scale.

RESULTS:

CFAs supported the conceptual framework of the PDQ with 3 confirmed sub-domains. Good consistency (i.e., internal reliability) of each scale was demonstrated (all Cronbach's alphas >0.70). Convergent and discriminant validity were shown in the pattern of associations between PDQ domains and other measures of PD. PDQ domain scores significantly differed between patients with or without ED and between patients with or without PD-related symptom distress, further supporting the construct validity of the PDQ.

CONCLUSIONS:

This study confirms the conceptual framework, factor structure, and convergent and discriminant validity of the PDQ Psychological and Physical Symptoms, Penile Pain, and Symptom Bother domains. Used in conjunction with objective penile curvature measurements, the PDQ can serve as a valuable diagnostic tool or outcome measure for assessing treatment-related improvements in PD symptoms.