Objective: To present and describe the validity and reliability of the International Continence Society-Benign Prostatic Hyperplasia study quality-of-life (ICSQoL) instrument, a new set of questions to assess the impact of lower urinary tract symptoms (LUTS) on quality of life (QoL) in middle-aged and elderly men.
Patients and methods: The study comprised 1271 consecutive men over the age of 45 years, attending urology departments in 12 countries, with LUTS and possible benign prostatic obstruction who were recruited to the ICS-'BPH' study (the clinic group); 423 ambulant men were recruited from a general practice in the UK to provide a community group. Each individual completed the ICS-'BPH' study questionnaire which includes six items addressing general and specific aspects of QoL (the ICSQoL). Content and construct validity were assessed by interviews with patients and by testing hypotheses within the study groups, e.g. the relationships with age, individual LUTS (as measured on the ICSmale questionnaire) and generic health status, as measured by the Short Form (SF-36) and EuroQol instruments. Reliability was assessed by measures of internal consistency and a test-retest analysis.
Results: The ICSQoL items were easily understood by patients, were completed with low levels of missing data, and address some (but not all) concerns about the impact of LUTS on QoL. The ICSQoL items have good construct validity, showing expected differences between community and clinic samples, and expected relationships with each other and individual LUTS. Items had good test-retest reliability, but their internal consistency was poor, confirming that ICSQoL questions should not be combined into a score. General ICSQoL items were closely related with most domains of the SF-36 and the EuroQol.
Conclusion: ICSQoL items may be used individually or as a group in research studies or in clinical practice.