The psychometric validation of a US English satisfaction measure for patients with benign prostatic hyperplasia and lower urinary tract symptoms

BACKGROUND: The purpose of the current study was to validate the US English Patient Perception of Study Medication (PPSM) questionnaire, which measures patient satisfaction with Benign Prostatic Hyperplasia (BPH) treatment and was administered to men with BPH lower urinary tract symptoms (LUTS) enrolled in a multi-national clinical trial. METHODS: Patients with moderate to severe BPH symptoms completed three disease-specific measures: The International Prostate Symptom Score (IPSS), the BPH Impact Index (BII) and the PPSM, at baseline (after completion of the placebo run-in period) and at every 13-week clinic visit thereafter for the duration of the study treatment period. The PPSM was analysed to assess its variability, reliability and validity. RESULTS: There were 879 patients included in the analyses, with a mean age of 66.7 years. The PPSM was found to comprise two factors – PPSM-Global and PPSM-Pain, with a Total Score ranging from 7 to 49. It demonstrated good internal consistency (Cronbach's alpha ranged from .95 to .97) and also demonstrated convergent validity through significant correlations with the IPSS (.48 to .58), IPSS Quality of Life (QoL) item (.41 to .63) and BII (.31 to .45) and known-groups validity against the IPSS, IPSS QoL item and BII. CONCLUSION: Results support the use of the PPSM as a measure of satisfaction in BPH patient groups.