Psychometric Properties of Functional Assessment of Cancer Therapy-Prostate (FACT-P) in Chinese Patients with Prostate Cancer

Abstract

Purpose: The aim of the study was to assess the validity, reliability and sensitivity of the FACT-P (Version 4) in Chinese males with prostate cancer. Methods: Construct validity was assessed using Spearman's correlation test against the 12-item Short Form Health Survey (SF-12v2). Internal consistency and test-retest reliability was assessed using Cronbach's α coefficient and intra-class correlation coefficient, respectively. Sensitivity was determined by performing known group comparisons by independent t-test. Results: FACT-P subscale scores had a moderate correlation with the corresponding SF-12v2 domain score that conceptually measures the similar construct providing evidence for adequate construct validity. Internal consistency was acceptable (α: 0.687-0.900) for all subscales aside from the Prostate Cancer Subscale (α: 0.505) and Trial Outcome Index (α: 0.562). FACT-P subscale and total scores showed good test-retest reliability (range: 0.753-0.913). All total scales and most of the subscales were sensitive in detecting differences between subjects with different levels of functional impairment but not different cancer stages or levels of prostate-specific antigen. Conclusions: The measure is a valid and reliable measure to assess the health-related quality of life of Chinese males with prostate cancer. The FACT-P is sensitive to detect difference between subjects with varying functional status.