The aim of this study was to evaluate the psychometric properties of the Menopause-Specific Quality of Life Questionnaire (MENQOL) in a sample of breast cancer survivors experiencing menopausal symptoms.
This was a secondary analysis of MENQOL psychometric data from two larger parent studies investigating acupuncture for the relief of menopausal symptoms among breast cancer survivors. Reliability was assessed for each subscale of the MENQOL via (1) internal consistency reliability with Cronbach α and (2) test-retest reliability at multiple follow-up points with intraclass correlation coefficients and r. Convergent and discriminant validities were assessed via correlations of the vasomotor and psychosocial MENQOL subscales with select items in the Kupperman index and daily symptom diary. A principal components analysis was performed to determine construct validity.
For each subscale, Cronbach α was 0.70 or greater. All subscale test-retest reliabilities at first follow-up were significant and at least moderately correlated (≥0.450; r's and intraclass correlation coefficients). Convergent validity was moderate between the vasomotor and psychosocial subscales and the symptom diary (r ≥ 0.410, P < 0.001) and larger between these domains and the Kupperman index (r ≥ 0.614, P < 0.001). In the same subscales, discriminant validity was supported by low, nonsignificant correlations (r ≤ 0.176, P > 0.05). The principal components analysis revealed a latent structure nearly identical to the prespecified instrument domains, with the exception of the physical domain.
With results comparable with those obtained in previous psychometric work, the MENQOL seems to be a reliable and valid instrument to assess quality of life in postmenopausal breast cancer survivors.