Psychometric evaluation of a Swedish version of Minneapolis-Manchester quality of life-youth form and adolescent form

BACKGROUND It has become important to measure long-term effects and quality of life in survivors of childhood cancer. The Minneapolis- Manchester Quality of Life (MMQL) instrument has been proven to better capture the quality of life (QoL) perspective of health than other instruments. The instrument has age appropriate versions and is therefore favourable for longitudinal studies of QoL of children surviving from cancer. The aim of this study was to evaluate the psychometric properties of the Swedish version of MMQL-Youth Form and the Adolescent Form focusing on: 1) face and content validity 2) the internal consistency and 3) the test-retest reliability. METHODS The sample consisted of 950 pupils (11-16 years old) from 7 schools in the western Sweden who completed the questionnaire. For the test-retest evaluation 230 respondents completed the questionnaire two weeks later. RESULTS Face and content validity was supported and internal consistency was found to be acceptable for the total scale for both the MMQL-Youth Form (8-12 years of age) and the Adolescent Form (13-20 years of age). Test-retest reliability for the MMQL-Youth Form was moderate for 50% of the items and good for the remaining. For the MMQL-Adolescent Form the test-retest showed moderate or good agreement for 80% of the items and fair for 20%. CONCLUSIONS The result indicated that the Swedish version of the MMQL-Youth Form and Adolescent Form was valid and reliable in a sample of healthy children in a Swedish context. It is recommended to test the instrument among diverse samples of children such as survivors of childhood cancer in order to validate its usefulness in research and clinical settings.