Validation and Application of the Lymphedema Life Impact Scale (LLIS); A Condition-Specific Measurement Tool for Persons with Lymphedema
By: Jan Weiss, PT, DHS, CLT-LANA, Cox Health, Springfield, MO
Lymphedema (LE) is a condition manifesting as swelling when the lymphatic system fails to successfully remove excess tissue interstitial fluid. It may result from varying etiologies, but commonly is associated with cancer treatment. Numerous impairments and activity limitations associated with LE have been shown to adversely affect quality of life.1,2,3 Most literature reporting the effects of LE on quality of life have utilized either generic quality of life (QOL) instruments such as the SF 36 and Nottingham Health Profile, or cancer-related outcome measures including the Functional Assessment of Cancer Therapy (FACT), Functional Living Index-Cancer (FLIC) and the European Organization for Research and Treatment of Cancer-Quality of Life Questionnaire (EORTC-QLQ C30). The difficulty in using those measures is the lack of sensitivity to issues relating to LE.
Due to the specific impact of lymphedema, it is important to use a condition-specific measure to assess the effects of all kinds of LE upon patients, and on which to plan and base appropriate treatment.4,5 Several condition-specific functional or health-related quality of life questionnaires have been reported in LE research in recent years; however most are designed to measure only upper limb LE following breast cancer. Among these are the Upper Limb Lymphedema 27 (ULL27)6, the Lymphedema Functioning, Disability and Health Questionnaire (Lymph-ICF)7, the Wesley Clinic Lymphedema Scale (WCLS)8 and the Lymphedema Breast Cancer Questionnaire (LBCQ). Few patient-reported outcome-measuring instruments exist to measure the impact of all-type and any extremity LE. Although there has long been a recognized need for better outcome reporting for patients with LE, there has remained a dearth of good condition-specific outcome measures. The LYMQOL is the only known English QOL instrument available to measure all types and any extremity LE.9
The Centers for Medicare and Medicaid Services in the U.S. implemented a requirement in 2013 for documentation of functional outcomes, impairment categorization, and severity (G-codes) for rehabilitation. This necessitated the need for a comprehensive instrument for all-types and any extremity LE and a means by which severity of condition could be established. The Lymphedema Life Impact Scale (LLIS) was developed by a LANA-Certified Lymphedema Therapist as a comprehensive LE-specific instrument to measure impairments, activity limitations, and participation restrictions in those living with any extremity LE. This 18-question assessment tool includes physical, psychosocial, and functional domains.
Research was undertaken to investigate the reliability and validity of the Lymphedema Life Impact Scale (LLIS) in the LE patient population. The LLIS was validated against valid outcome measures currently used in LE research. A study was conducted on 34 patients (3 male, 31 female) with unilateral, bilateral, upper or lower extremity LE. Location of edema was 15 upper extremity and 19 lower extremity. The most common cause of edema was cancer, and mode of duration of edema was 6-10 years.
Validation of a new instrument involves extensive research to see that the new instrument measures what it is intended to measure within a specified population.10 Establishing reliability, content, and criterion validity are essential to this process. Reliability of the LLIS was established through Cronbach’s alpha calculation of each domain of the LLIS. Content validity was ascertained by ranking of LLIS questions by experts in the field of LE management. Each question on the LLIS was ranked (1-4) according to perceived pertinence to those living with LE (1 = question not pertinent to those with LE; 4 = strongly pertaining to LE). Criterion validity was assessed through correlation of the LLIS with other validated outcome measures currently used in LE research: the EORTC, LYMQOL, DASH (for upper limb function), and the LEFS (for lower limb function).
The usefulness of the LLIS is greatly supplemented by combining it with an Excel program designed to calculate the LLIS scores into a Medicare “G-Code”. Through a mathematical calculation, the G-Code Calculator assigns an impairment severity according to Medicare dysfunction levels. This program was developed by a second LANA-Certified Lymphedema Therapist who was using the LLIS and realized the need for such a program to meet Medicare requirements.
Cronbach’s alpha measure of reliability was >.823 for each domain on the LLIS. This represented good (>.70) internal consistency. Content validation for “expert ranking” of questions on the LLIS was >3.0/4.0 for all questions. The LLIS was shown to have high correlation (>.70) with the LYMQOL, DASH, and functional domain of the EORTC- QOL C30.
Measurements of reliability and convergent validity are robust despite the small sample size. The LLIS fills a void in outcome measures for the all-types and any extremity lymphedema patient population. The instrument is short and quick to administer and when combined with a proprietary Excel spreadsheet calculator, is useful for Medicare severity coding. The application of the LLIS and calculator open new avenues to clinical documentation and research in the field of LE treatment.
Data will continue to be gathered to strengthen validity of the LLIS in the lymphedema population as well as to determine instrument responsiveness and psychometrics.
Access to LLIS and G-Code Calculator
The LLIS alone, or in combination with the G-Code Calculator, is available exclusively through Klose Training at www.klosetraining.com. (Click on the Resources tab at the top of the home page.) For questions or information, please contact jan [at] klosetraining.com for the LLIS or lindah [at] klosetraining.com
for the G-Code Calculator.
I wish to thank all of the lymphedema therapists and patients across the U.S. who assisted with survey submission, and Dr. Todd Daniel at Missouri State University RStats Institute for his invaluable assistance with statistical analysis and project design.
- Ridner SH, Deng J, Fu MR, et al. Symptom burden and infection occurrence among individuals with extremity lymphedema. Lymphology. 2012;45(3):113-123.
- Hormes JM, Bryan C, Lytel LA, et al. Impact of lymphedema and arm symptoms on quality of life in breast cancer survivors. Lymphology. 2010;43(1): 1-13.
- Morgan PA, Franks PJ, Moffatt CJ. Health-related quality of life with lymphedema: A review of the literature. Int. Wound J. 2005;2:47-62.
- Pusic AL, Cemal Y, Albornoz C, Klassen A, et al. Quality of life among breast cancer patients with lymphedema: a systematic review of patient-reported outcome instruments and outcomes. J Cancer Surviv. 2013;7:83-92.