Psychometric properties of Functional Assessment of Cancer Therapy-Prostate (FACT-P) in Chinese patients with prostate cancer

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. 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 were assessed using Cronbach's alpha coefficient and intra-class correlation coefficient, respectively. Sensitivity was determined by performing known-group comparisons by independent t test. 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 (alpha: 0.687-0.900) for all subscales aside from the Prostate Cancer Subscale (alpha: 0.505) and Trial Outcome Index (alpha: 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 patients with different levels of functional impairment but not different cancer stages or levels of prostate-specific antigen. 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 patients with varying functional status.