VALIDATION OF THE LYMPHEDEMA LIFE IMPACT SCALE (LLIS): A CONDITION-SPECIFIC MEASUREMENT TOOL FOR PERSONS WITH LYMPHEDEMA.

Evidence-based practice supports the use of validated outcome measures to assess the impact of lymphedema; however, condition-specific lymphedema assessment measures are needed. The Lymphedema Life Impact Scale (LLIS) was developed as a comprehensive, lymphedema-specific instrument to assess the effects of lymphedema in any extremity. The LLIS is an 18-item measure of physical, psychosocial, and functional impairments caused by lymphedema. The purpose of this multicenter, cross sectional study was to investigate the reliability and validity of the LLIS. Test-retest reliability was assessed in a subgroup of 17 participants. Internal consistency and validity was assessed in 71 participants with upper (nUE = 37) or lower limb (nLE = 34) lymphedema, and a control group of 31 participants without lymphedema. Intraclass correlation coefficients for test-retest reliability ranged from .965 to .990. Cronbach's alpha coefficients for internal consistency ranged between .841 and .926. Construct validity of the LLIS was upheld with symptoms, but not with edema severity. The LLIS correlated highly with other comparison measures used in this study. Minimal clinically important difference of the LLIS was 7.31; MDC95 = 11.53. Our results showed the LLIS to be a valid and reliable tool for the assessment of severity of impairment among patients with lymphedema.