Development and validation of a telephone questionnaire to characterize lymphedema in women treated for breast cancer.

BACKGROUND AND PURPOSE Accurate and economical characterization of lymphedema is needed for population-based studies of incidence and risk. The purpose of this study was to develop and validate a telephone questionnaire for characterizing lymphedema. SUBJECTS Forty-three women who were treated previously for breast cancer and who were recruited from physical therapy practices and a cancer support organization were studied. METHODS Questionnaire assessment of the presence and degree of lymphedema was compared with physical therapists' diagnoses, based primarily on circumferential measurements. Twenty-five of the 43 subjects were measured independently by 2 physical therapists to assess interobserver agreement. RESULTS Interobserver agreement on clinical assessments of the presence and degree of lymphedema was high (20/25, weighted kappa=.80); all of the disagreements were between judgments of whether there was no lymphedema or mild lymphedema. For the diagnosis of at least moderate lymphedema (differential in the circumferences of the upper extremities greater than 2 cm), sensitivity of the questionnaire varied from 0.86 to 0.92 and specificity was 0.90. However, sensitivity (varying from 0.93 to 0.96) was higher than specificity (varying from 0.69 to 0.75) for the diagnosis of any lymphedema. DISCUSSION AND CONCLUSION A few straightforward questions exhibited excellent agreement with physical therapists' assessments for identifying at least moderate lymphedema.