Research

Psychometric properties of a prostate cancer radiation late toxicity questionnaire

George Rodrigues^1,2 , Glenn Bauman¹ , Michael Lock¹ , David D'Souza¹ and Jeff Mahon^2,3

¹  Department of Oncology, University of Western Ontario, London, Ontario, Canada

²  Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada

³  Department of Medicine, University of Western Ontario, London, Ontario, Canada

author email corresponding author email

Health and Quality of Life Outcomes 2007, 5:29doi:10.1186/1477-7525-5-29

Published:	31 May 2007

Abstract

Background

To construct a short prostate cancer radiation late toxicity (PCRT) questionnaire with health-related quality-of-life (HRQoL) domains.

Methods

The PCRT was developed by item generation, questionnaire construction (n = 7 experts, n = 8 focus group patients), pilot testing (n = 37), item reduction (n = 100), reliability testing (n = 237), and validity testing (n = 274).

Results

Reliability of the three item-reduced subscales demonstrated intraclass correlation coefficients (CC) of 0.811 (GU), 0.842 (GI), and 0.740 (sexual). Discriminant validity demonstrated Pearson CC of 0.449 (GU-GI), 0.200 (sexual-GU), and 0.09 (sexual-GI). Content validity correlations between PCRT-PCQoL were 0.35–0.78, PCRT-FACT-G^© were 0.19–0.39, and PCRT-SF-36^® were 0.03–0.34.

Conclusion

We successfully generated a PCRT HRQoL questionnaire including subscales with very good psychometric properties.