Validation of the Lymphedema Life Impact Scale Version 2: A Condition Specific Measurement Tool for Persons With Lymphedema

Jan Weiss; Todd Daniel. Rehabilitation Oncology 2018; 36:28–36

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Validation of the Lymphedema Life Impact Scale Version 2: A Condition Specific Measurement Tool for Persons with Lymphedema

Jan Weiss; Todd Daniel. Rehabilitation Oncology 2018; 36:28–36

Background: Evidence-based practice supports the use of validated outcome measures to assess the effect of lymphedema; however, condition-specific lymphedema assessment measures are needed. The Lymphedema Life Impact Scale (LLIS) has been validated as a comprehensive lymphedema-specific instrument to assess the effects of lymphedema in any extremity.

Objectives: This multicenter, cross-sectional study investigated the reliability and validity of a revised version of the LLIS, known as LLIS version 2.

Methods: Qualifying patients from lymphedema clinics across the United States completed self-report outcome measures; clinicians measured limb circumference. Test-retest reliability was assessed in a subgroup of 21 participants. Internal consistency and validity were assessed in 84 participants with upper- or lower-limb lymphedema.

Results: Intra class correlation coefficients for test-retest reliability ranged from 0.687 to 0.895. Cronbach α coefficients for internal consistency ranged between 0.847 and 0.953. Construct validity of the LLIS was upheld with symptoms but not with edema severity. The LLIS correlated from moderately to highly with most domains of the comparator LYMQOL (Lymphedema Quality of Life scale) used in this study. Minimal clinically important difference of the LLIS was 7.27; MDC95 was 12.74.

Limitations: Despite adequate group sizes, the vast majority of participants were white females, so generalizations to male patients or to those of different races should be done cautiously. Conclusions: LLIS version 2 is a valid and reliable tool for the assessment of severity of impairment among patients with lymphedema.

Main findings

  • This lymphedema-specific instrument meets all the goals met with LLIS version1: (a) to assess lymphedema-specific impairment, (b) measure any extremity lymphedema, (c) inquire about infection incidence, and (d) to satisfy US Medicare documentation requirements by calculating functional outcomes with its own G code calculator. The purpose of this study was to assess the reliability and validity of LLIS version 2.
  • LYMQOL was used to assess criterion validity for LLIS version 2. Patients completed a demographic survey, a symptom scale checklist of 6 symptoms frequently associated with lymphedema, the LYMQOL, and LLIS version 2 questionnaires. The LYMQOL is a lymphedema-specific, self-report assessment tool measuring 4domains of QOL (symptoms, appearance, function, and mood).13 The LLIS comprises 18 questions measuring physical, psychosocial, and functional domains with responses ranked 0 to 4, where 0=no impairment and 4=severe impairment. The question regarding infection is Rehabilitation Oncology Validation of the Lymphedema Life Impact Scale 29 in its own domain, with scoring0= no episodes of infection and 4=4+episodes of infection in the past year.
  • The LLIS contributes to the field of lymphedema treatment by offering a condition-specific outcome measure for lymphedema, serving to benefit lymphedema research and clinical practice. The instrument is short and quick to administer. It measures treatment outcomes and when combined with an Excel spreadsheet calculator is able to calculate Medicare functional impairment. LLIS version 2 has demonstrated validity and reliability in the population with any extremity lymphedema and can be used in place of measures that are not condition-specific, providing additional accuracy in detecting impairment and treatment outcomes in patients with lymphedema.