The ICS–‘BPH’ Study: the psychometric validity and reliability of the ICS male questionnaire

OBJECTIVE: To assess the validity and reliability of the ICSmale questionnaire developed for the International Continence Society-'Benign Prostatic Hyperplasia' (ICS-'BPH') study. PATIENTS AND METHODS: Urology departments in 12 countries recruited 1271 consecutive men > 45 years old, with lower urinary tract symptoms and possible benign prostatic obstruction, to the ICS-'BPH' study (the clinical group); 423 ambulent men were recruited from a general practice in the UK to provide a community group. Each individual was asked to complete the wide-ranging ICSmale questionnaire, comprising questions concerned with urinary symptoms, the bother they cause, and issues of quality of life and sexual function. Content, construct and criterion validity of the symptom and problem questions were assessed by interviews with patients and urologists, testing hypotheses within sub-studies, and in relation to frequency-volume diaries and uroflowmetry. Reliability was assessed by measures of internal consistency and a test-retest analysis. RESULTS: The ICSmale questionnaire was easy to complete. It was clearly able to differentiate between men in clinical and community populations, and detected the expected positive age gradient for most symptoms in the community group. There was reasonable agreement between relevant parts of the questionnaire and frequency-volume charts when a relatively flexible approach was taken, but there was a very poor relationship between questions assessing strength of stream and the results of uroflowmetry. Internal consistency was high, and overall the questionnaire demonstrated good test-retest reliability. CONCLUSION: The self-completed ICSmale questionnaire had high levels of psychometric validity and reliability.