Development and validation of a self-report lower-extremity lymphedema screening questionnaire in women

Abstract

Background. Patient-reported signs and symptoms are often the first indication of clinically relevant lymphedema. Objective. The purpose of this study was to develop and assess the diagnostic accuracy of a screening questionnaire to detect lower-extremity lymphedema (LEL) among normal-weight women and women with obesity. Design. This was a cross-sectional survey study. Methods. The authors reviewed existing questionnaires assessing upperextremity lymphedema (UEL) for potential questions and worked with content experts to generate new items. A draft questionnaire with 59 items was reviewed by 5 physicians and 5 physical therapists who specialized in lymphedema management and 5 female patients with clinically confirmed secondary LEL. A revised questionnaire with 45 items was administered by mail to 186 women with clinically confirmed LEL (n=116) or UEL (n=70). A total of 99 women (53.2% of 186) completed the mailed survey, and 28 women with lymphedema who were recruited directly in a lymphedema clinic waiting area also completed the survey. A parsimonious subset of items that best discriminated patients with and without LEL was identified using chi-square tests and logistic regression. Sensitivity and specificity for detecting LEL and positive and negative likelihood ratios (LR+, LR-) were estimated for the entire sample and for subsamples defined by obesity (body mass index ≥30 versus <30 kg/ m2), which may confound the accurate diagnosis of LEL. Results. Questionnaires were completed by 127 women (LEL group, n=88; UEL group, n=39). A sum of 13 items (score range=0-52) was the most discriminating. Using a cutoff score of ≥5 points, the sensitivity and specificity for detecting LEL among all participants were 95.5% and 86.5%, respectively (LR+=7.1, LR-=0.05), and 94.8% and 76.5%, respectively (LR+=4.0, LR-=0.07), for participants who were obese. Limitations. By enumerating a sample with a high prevalence of LEL, a spectrum bias may have been introduced, which may have affected the accuracy of the screening questionnaire. Conclusions. The brief, 13-item self-report questionnaire is a sensitive and specific tool for detecting clinically relevant LEL among women, including those with a body mass index of ≥30 kg/m2. © 2013 American Physical Therapy Association.