Japanese Version of the Quality of Life Measurement for Limb Lymphedema(leg)(J LYMQOL l):its Reliability and Validity
BACKGROUND:Lymphedema is a condition that manifests as swelling when the lymphatic system fails to remove excess interstitial fluid from the tissues. Cancer treatments, such as radical surgery including lymph node dissection, chemotherapy, and radiotherapy, contribute to the risk of secondary lymphedema. To plan the treatment for lymphedema and monitor the patient s progress, leg or arm swelling and function of the limbs need to be assessed. OBJECTIVE:The purpose of this study was to investigate the reliability(test retest, internal consistency)and validity(criteria related validity, construct validity)of data obtained with the Japanese version of the Quality of Life Measurement for Limb Lymphedema(leg)(J LYMQOL l) METHOD:Two hundred and eleven women with lower limb lymphedema were recruited between September 2012 and October 2013 from the lymphedema outpatient services in four Tohoku areas and one Kanto area of Japan, and were assessed by self administered questionnaires that included the J LYMQOL l. RESULTS:The Cronbach s alpha coefficient of the J LYMQOL l was .925, and subscales ranged from .898 to .944, p<.05, indicating a high internal reliability of the tool. Test retest reliability was moderate(r=.589, p< .05) A confirmatory factor analysis revealed that the four factor model of the J LYMQOL l fitted the data. The Pearson correlation coefficient, between the J LYMQOL l and JEORTC QLQ C30, was .702, indicating a high criteria related validity for all domains, except one. CONCLUSION:The J LYMQOL l has high construct validity and reliability and can be used for clinical assessment of QOL in patients with lower limb lymphedema.