Development and psychometric evaluation of a lymphoedema self-management behaviour questionnaire for breast cancer patients.

OBJECTIVES:The study was aimed to develop and evaluate a lymphoedema self-management behaviour questionnaire (LSMBQ) for breast cancer patients. METHODS:The initial version of the behaviour questionnaire was developed based on the framework of self-management and the evidence summary of lymphoedema self-management. Two rounds of expert consultation were conducted to validate the questionnaire's content validity. A cross-sectional survey was then conducted in breast wards of two hospitals in China to evaluate the reliability and validity of this scale. Exploratory structural equation model was used to test the construct validity. T-test was used to analyse the known group validity. Structural equation model was applied to verify the relationship between self-efficacy, social support, and lymphoedema self-management behaviour to test the convergent validity. Also, the internal consistency reliability and test-retest reliability were evaluated. RESULTS:The questionnaire's content validity was satisfactory. There were 22 items included in the LSMBQ for validation and 260 completed the survey. A six-factor structure with good construct validity was identified. The result of t-test verified that patients who knew the risk of lymphoedema and those who received lymphoedema health education had higher scores of lymphoedema self-management behaviours (P < 0.05), indicating that the questionnaire has good known group validity. The fitting results of the structural equation model indicated that the 22-item questionnaire had good convergent validity. Cronbach's alpha coefficients and test-retest reliability for the total questionnaire were 0.910 and 0.875, respectively. CONCLUSIONS:The 22-item LSMBQ appears to have adequate reliability and validity to assess the lymphoedema self-management behaviours for breast cancer patients.