Bringing prostate cancer quality of life research back to the bedside: translating numbers into a format that patients can understand.

PURPOSE: Although measuring quality of life of patients with prostate cancer serves important research goals, its primary clinical purpose is informing patients. Sophisticated quality of life measures produce purely numerical results that patients have difficulty understanding. We present an approach that preserves the methodological strengths of validated multi-item measures but provides more accessible information for clinical use.
MATERIALS AND METHODS: Using validated indexes measuring urinary, bowel and sexual function we surveyed patients with clinically localized prostate cancer before treatment and at intervals thereafter. Based on patient responses to parallel distress measures we defined 3 levels of function, including normal-no abnormal symptom, intermediate-any abnormal symptom but none severely abnormal and poor-any severely abnormal symptom. We then translated patient survey results into these levels. To assess measurement properties we compared average symptom distress scores in patients at each symptom level.
RESULTS: Levels of function and patient distress scores correlated strongly. Large and approximately equal differences in distress scores separated patients at successive levels in all symptom indexes (effect size greater than 1.2, p < 0.0001). Using these categories we created tables showing 24-month outcomes in 417 previously reported patients by pretreatment symptom level and treatment, providing a tool for patients to determine posttreatment outcomes in similar patients.
CONCLUSIONS: Using symptom indexes to define levels of function produces a quality of life metric that is valid, defines quantitative intervals, is transparent and may be more useful to patients. This approach provides methodologically sound outcome information to patients attempting to choose a prostate cancer treatment.