Objective: To validate the Danish Prostatic Symptom Score (DAN-PSS-1), a self-administered quality-of-life questionnaire comprising 12 questions related to voiding problems and the perceived bother of each individual symptom.
Methods: Using published results from several comparisons of other symptom scoring systems with DAN-PSS-1, the test-retest reliability, internal consistency, construct and content validity, and responsiveness of the DAN-PSS-1 system were assessed.
Results: The system was internally consistent (Cronbach's alpha = 0.73), the median test-retest reliability of answers to each question was 83.5% (range 0-99.7%) and the questionnaire was well understood by the patients. The DAN-PSS-1 system demonstrated a high degree of construct validity, correlating with the extensively used Madsen-Iversen score system (Spearman's correlation coefficient, rs = 0.51) and with the patients' answers to questions about how bothersome their symptoms were (rs = 0.71). The DAN-PSS-1 system discriminated clearly between patients with benign prostatic hyperplasia (BPH) and control subjects (an area under the receiver operating characteristic curve of 0.94). Finally, the DAN-PSS-1 was sensitive to changes following intervention, with scores decreasing from a median of 20 to zero 4 months after patients underwent transurethral prostatectomy and from a median of 11.5 to 7.5 (65%) after patients had received 4 months treatment with an alpha-blocker.
Conclusions: The DAN-PSS-1 system is reliable, valid and responsive, and therefore can be recommended for assessing the severity of symptoms among patients presenting with lower urinary tract complaints suggestive of BPH and in the follow-up after intervention.