Development and Validation of the Lymphedema Symptom Intensity and Distress Survey-Lower Limb

Sheila H. Ridner, PhD,1 Jennifer K. Doersam, MS,1 Deonni P. Stolldorf, PhD,1 and Mary S. Dietrich, PhD1,2 Lymphatic Research Biology, 2018

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Development and Validation of the Lymphedema Symptom Intensity and Distress Survey-Lower Limb

Sheila H. Ridner, PhD,1 Jennifer K. Doersam, MS,1 Deonni P. Stolldorf, PhD,1 and Mary S. Dietrich, PhD1,2 Lymphatic Research Biology, 2018

Background: Lymphedema is a chronic, incurable condition that occurs most commonly in lower limbs (legs and feet). Increased morbidity is seen with this form of lymphedema, but there are few studies and even fewer tools intended to assess symptom burden in patients impacted by this condition. A questionnaire, the Lymphedema Symptom Intensity and Distress Survey-Lower Limb (LSIDS-L), was developed to fill this gap. The measure is composed of several clusters of symptoms thought to characterize lower limb lymphedema. The initial work was conducted to propose and assess the face validity of the clusters. Subsequently, work was undertaken to empirically evaluate the presence of the symptom clusters, assess the reliability of the cluster scores, and evaluate the validity of the scores by studying associations with other valid measures.

Methods and Results: During the initial work, the LSIDS-L was tested with lower limb lymphedema patients only, and in the subsequent work the LSIDS-L and valid measures were administered to patients with no lymphedema and with lower limb lymphedema. A total of 388 volunteers participated, 111 of whom indicated no diagnosis of lymphedema, and 277 indicated a diagnosis of lower limb lymphedema. Cluster analysis resulted in the exclusion of 5 items, yielding 8 clusters with a total of 31 items. Cluster scores demonstrated acceptable internal consistency, distinguished non lymphedema patients from lower lymphedema patients, and demonstrated expected convergent and divergent validity with other valid measures.

Conclusion: The LSIDS-L is a valid tool for detecting and quantifying symptom burden in patients with lower limb lymphedema.

Main findings

  • There are few symptom assessment tools for use in patients with lower limb lymphedema.
  • In the United States, Medicare now requires verification of functional change by some objective measure, intensifying the need for a comprehensive assessment of lymphedema-related symptoms and their impact on patients.
  • The purpose of this article is to report on the further refinement and testing of this instrument.
  • The initial study of the face validity and composition of the LSIDS-L included only individuals with lower limb lymphedema. The extension of that work reported on here included not only those individuals but also additional, newly recruited individuals with and without lymphedema.
  • There were a total of 277 participants with lower limb lymphedema and 111 without completed the LSIDS-L measure.
  • Approximately 20% could not identify the cause of their lymphedema (n=55). Of those reporting a known cause (n=222), 51.4% indicated primary lymphedema, while 48.6% indicated that their lymphedema was secondary to cancer (47.2%), non cancer (47.2), or other/unknown events (5.6%).
  • Seven clusters with a total of 30 symptoms were previously identified in patients with arm lymphedema. Those same symptom clusters were mirrored in the lower limb sample in this study: activity, soft tissue sensation, resources, bio behavioral, neurological sensation, sexuality, and functional. Yet in this study, a distinct cluster of pain-related symptoms emerged.
  • The instrument appears to be a viable option for symptom assessment in this population.