The Minneapolis-Manchester Quality of Life instrument: Reliability and validity of the Youth Form.

Abstract

Improvements in survival after childhood cancer have increased emphasis on health-related quality of life (HRQoL) of survivors. We developed the Minneapolis-Manchester Quality of Life-Youth Form (MMQL-YF) as a standardized patient self-report instrument designed to assess HRQoL in childhood cancer survivors between the ages of 8 and 12 years. To validate the instrument, the MMQL-YF was administered to 643 children (481 healthy, 162 with cancer). Factor analysis was conducted to refine the instrument, and Cronbach's alpha coefficient was used to measure its internal reliability. Known-groups validity was determined by comparing healthy children with those with cancer. Construct validity was studied by a comparison of similar domains in the MMQL-YF and the Child Health Questionnaire (CHQ). Stability was tested by re-administration of the MMQL-YF 2 weeks later. Internal consistency reliability was in the acceptable range for this instrument. The MMQL-YF was able to distinguish between known groups, and its scales correlated highly with similar CHQ domains. Test-retest reliability showed that the instrument was extremely stable in all scales tested. Data provide evidence for the validity and reliability of the MMQL-YF as a comprehensive, multidimensional, self-report instrument for measuring HRQoL among childhood cancer survivors.