Confirming the factor structure of a generic quality of life instrument among pre-treatment substance use disorder patients.

BACKGROUND: Quality of life (QoL) is a patient-reported outcome of increasing importance in the substance use disorder (SUD) treatment field, and impaired QoL may be an important impetus for treatment uptake. Instruments and methodologies abound, precluding comparison, as does a dearth of population norms. The QOL10 is a generic, overall QoL tool containing ten items and with simple scoring procedures. It is therefore a potential alternative to the gold standard WHOQOL-BREF. This study aimed to assess the two-factor structure of the QOL10 that has been suggested by a previous exploratory factor analysis. METHODS: Adults entering 21 participating inpatient or outpatient SUD treatment were recruited to join a national longitudinal cohort study. 531 completed the QOL10 at treatment entry and were included in the analysis. Structural equation modelling (SEM) was used to confirm the model fit of a two-factor structure, and the scaling qualities of the QOL10 were reported. RESULTS: According to the SEM analysis, the QOL10 was comprised of one latent variable measuring social QoL, and one measuring global QoL, and all ten items were retained. Goodness of fit tests included: root mean square of approximation = 0.063, 90% CI 0.050-0.076; normed-fit index = 0.919; and comparative fit index = 0.943. CONCLUSIONS: The QOL10 should be considered when clinicians in the SUD treatment field need a short, valid instrument that measures both global QoL and social QoL, with minimum respondent and administrator burden. The social domain is of particular utility and may be used as a stand-alone instrument. Test-retest reliability should be established in future studies.

A brief instrument to measure health-related quality-of-life in patients with bone metastasis: validation of the German version of Bone Metastases Quality-of-Life-10 (BOMET-QoL-10).

AIMS: This prospective, epidemiologic study was designed to translate the original Spanish Bone Metastases Quality-of-Life-10 (BOMET-QoL-10) questionnaire and undertake a validation of the translated German version of BOMET-QoL-10 in Germany to assess health-related quality-of-life (HRQoL) in patients with bone metastases (BM). METHODS: The translation process included forward and backward translations, and a linguistic validation. Patients aged ≥18 years with histological confirmation of cancer, diagnosed with BM, life expectancy ≥6 months, and fluency in German were eligible for this study (enrolled consecutively in 33 outpatient centers in Germany). Patients were given the German version of BOMET-QoL-10, together with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire QLQ-C30 and EORTC QLQ-BM22 questionnaires at inclusion, 6 weeks, 3 months, and 6 months after inclusion. A debriefing questionnaire was administered at inclusion to determine patient acceptability and understanding. RESULTS: Data include 364 patients with BM (median age = 68 years; females = 71.7%). The BOMET-QoL-10 is brief and clear (median completion time = 5 minutes; >90% of patients completed the questionnaire without assistance). The BOMET-QoL-10 forms only one overall scale. All 10 items showed a substantial correlation with the first factor (factor loading, range = 0.58-0.86). BOMET-QoL-10 exhibits high internal consistency and reproducibility (Cronbach's alpha = 0.91; intra-class correlation coefficient = 0.76). BOMET-QoL-10 showed significant correlations (range = 0.69-0.79) both with EORTC QLQ-C30 and EORTC QLQ-BM22 within the functioning (physical, social, interference) and symptom (fatigue, pain) scales, displayed significant sensitivity to change in EORTC QLQ-BM22 scores, and proved the potential ability to detect change in HRQoL in patients with different disease status. LIMITATIONS: There was a high proportion of females in this study, which might represent a limitation. CONCLUSIONS: The German version of BOMET-QoL-10 is a valid, reliable, brief, and clear instrument able to measure HRQoL in patients with BM.