Estimating the Reliability and Validity of the Upper Extremity Functional Index in Women After Breast Cancer Surgery

BACKGROUND: Activity limitations as well as impairments such as pain, numbness, limitation of shoulder range of motion, and weakness are common and well documented during and after treatment for breast cancer. There is limited information regarding the measurement properties of patient-reported outcome measures of upper extremity activity limitation in this population. This study examined the reliability and validity of the Upper Extremity Functional Index (UEFI) in patients after surgery for breast cancer. PATIENTS AND METHODS: Measures of function, shoulder flexion range of motion, and pain were obtained for 53 women before and 2 weeks after surgery for breast cancer. To estimate UEFI test-retest reliability, a convenience sample of 20 patients was assessed on a second occasion within 48 hours of their 2-week postsurgery assessment. Convergent and discriminant construct validation methods were applied by examining correlations between UEFI scores and change scores with those of the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH), Functional Assessment of Cancer Therapy-Breast (FACT-B) +4 items, shoulder flexion range, and pain. RESULTS: UEFI test-retest reliability was estimated to be 0.87 (95% confidence interval, 0.69, 0.94), and the standard error of measurement was 4.8 (95% confidence interval, 3.7, 7.1) scale points. The 90% confidence interval for a given UEFI score was ±7.9 and minimal detectable change at 90% confidence (MDC₉₀) was ±11.1 points. UEFI correlations with the QuickDASH (cross-sectional -0.79 and longitudinal -0.62) were greater than with the FACT-B+4 and impairment measures. CONCLUSION: These results support and guide the use of the UEFI in patients after breast cancer surgery.