Self-assessed health-related quality of life in men being treated for prostate cancer with radiotherapy: instrument validation and its relation to patient-assessed bother of symptoms

Abstract

Objectives. To develop a psychometrically valid and clinically useful questionnaire to assess health-related quality of life (HRQOL) in patients with prostate cancer (PCa) undergoing external beam radiotherapy. The most important factors in three dimensions (bowel function [BF], urinary function [UF], and sexual function [SF]) were identified by patient survey. Methods. Three HRQOL dimensions were assessed using Likert-type questions. Responses were analyzed by factor analysis to create HRQOL scales. Reliability and validity of the scales were assessed. Because patients can suffer symptoms yet not report their lives to be affected, the scales were compared with patient-reported bother. Results. Two scales were identified within each dimension: BF, urgency and daily living; UF, urgency and weakness of stream; and SF, interest/satisfaction and impotence. Cronbach’s alpha for the scales ranged from 0.63 to 0.94, and item-scale correlations and item-scale divergence correlations supported scale validity. Rising median scores correlated with rising levels of perceived bother. Conclusions. The questionnaire is a suitable tool for assessing HRQOL in three distinct dimensions for patients undergoing radiotherapy for PCa. Six dimensions of HRQOL were found to be related to bother, suggesting important relationships to be monitored for patients. Urgency of bowel movements, urgency of urination, and level of interest/satisfaction in sex correlated most strongly with bother.