[Validity and reliability of DASH questionnaire in women who suffer from lymphedema as a side effect of a breast cancer treatment]

Introduction: DASH questionnaire was designed to assess upper limb function in musculoskeletal pathologies. The aim of this manuscript is to study the reliability and validity of this questionnaire, to determine if is adequate to use in women with lymphedema due to breast cancer treatment.

Methods: Prospective study in 65 women with lymphedema due to breast cancer treatment was done, in which the reliability of DASH score with internal consistency (Cronbach's alpha) and test-retest reproducibility 15 days' interval (interclass correlation coefficient) and validity by correlation with SF-36v2 and FACT-B+4 (r or Kendall's τ b) scores was investigated.

Results: The internal consistency and the test-retest were Cronbach's alpha 0.969 and interclass correlation coefficient 0.861, respectively. There was correlation between the DASH score with the SF-36v2 score, mainly in the areas of physical function, body pain and physical role (r 0.800, 0.738, and 0.682, respectively; p<0.001), and lowest with the emotional and social wellbeing. The DASH score had correlation with FACT-B+4 (0.836; p<0.001) and the subscales the upper limb score (r=0.816; p<0.001), and there was no correlation with the social/familiar subscale (r=0.193; p=0.216).

Conclusion: The DASH questionnaire is a reliable and valid tool to assess upper limb functionality in Spanish women with breast cancer related lymphedema.