Switching Breast Cancer Patients with Progressive Bone Metastases to Third-Generation Bisphosphonates: Measuring Impact Using the Functional Assessment of Cancer Therapy-Bone Pain

Because bone metastases cause significant pain, we developed a questionnaire to evaluate its nature, severity, and impact. This 16-item questionnaire is the Functional Assessment of Cancer Therapy-Bone Pain (FACT-BP). We also developed a 13/18-item questionnaire, the functional Assessment of Chronic Illness Therapy-Treatment Satisfaction-Bone Treatment Convenience and Satisfaction Questionnaire (EACIT-TS-BTCSQ), to evaluate patients' expectations and acceptance of bone specific therapies. We evaluated the performance of these scales in two clinical trials. In both trials, we enrolled patients with metastatic breast cancer, who had progressive bone metastases despite first-line therapy with pamidronate or clodronate. We administered intravenous zoledronic acid to 31 patients in one trial and oral ibandronate to 30 patients in the other. Patients completed the FACT-BP questionnaire and FACIT-TS-BTCSQ at baseline, then at Weeks 4, 8, and 12. The EA CTBP scale showed good internal consistency reliability [Cronbach's alpha (alpha) = 0.93-0.96]. There was evidence of construct validity, and known-group validity was supported by score shifts in the anticipated direction (Cohen's d effect size=0. 36). The FA CTBP score reflected clinical change as evidenced by differences in performance status. This cross-sectional anchor-based criterion suggested reasonable clinically important differences (effect size=0.36). The FACIT-TS-BTCSQ showed good internal consistency reliability for treatment expectation (alpha = 0.87) and treatment experience (alpha's = 0.89-0.92). The FACT-BP scale is meaningful and appears appropriate for broader use. The assessment Of satisfaction (EACIT-TS-BTCSQ) raised questions that will require further research. J Pain Symptom Manage 2009;38:244-257. (C) 2009 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.