The functional assessment of cancer therapy-BRM (FACT-BRM): A new tool for the assessment of quality of life in patients treated with biologic response modifiers

Purpose: This paper reports on the development and validation of two biologic response modifier (BRM) subscales for use with the Functional Assessment of Cancer Therapy-General (FACT-G) quality of life (QOL) questionnaire. Methods: Using the FACT-G as a base, 17 additional questions related to symptoms common to interferon and retinoid therapy were developed. Data collected at baseline (n = 191) and week 2 (n = 168) in a randomized trial of interferon +/-13-cis-retinoic acid in advanced renal cell carcinoma patients were used to validate this measure. Results: Using a combined empirical and conceptual approach, the 17 questions were reduced to 13 questions consisting of two subscales: 'BRM-physical' (7 items; baseline coefficient alpha(alpha) = 0.70; week-2 alpha = 0.75) and 'BRM-mental' (6 items; baseline alpha = 0.79; week-2 alpha = 0.78). Internal consistency of the trial outcome index (TOI) combining physical well-being, functional well-being and the BRM subscales, was 0.91 for baseline assessments and 0.92 for week 2. Discriminant validity was demonstrated for the TOI by its ability to differentiate among prognostic risk groups, and for the total FACT-G, TOI and total FACT-BRM scores by their ability to distinguish between groups differing in performance, response and toxicity status. Conclusions: The 'BRM-physical' and 'BRM-mental' subscales can be combined with the FACT-G to form the 'FACT-BRM' scale, useful for measuring QOL in cancer patients who are receiving treatment with biologic response modifiers.