Evidence on the longitudinal construct validity of major generic and utility measures of health-related quality of life in teens with depression.

PURPOSE

To examine the longitudinal construct validity in the assessment of changes in depressive symptoms of widely used utility and generic HRQL instruments in teens.

METHODS

392 teens enrolled in the study and completed HRQL and diagnostic measures as part of the baseline interview. HRQL measures included EuroQol (EQ-5D-3L), Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), Quality of Well-Being Scale (QWB), Pediatric Quality of Life Inventory (PEDS-QL), RAND-36 (SF-6D), and Quality of Life in Depression Scale (QLDS). Youth completed follow-up interviews 12 weeks after baseline. Sixteen youth (4.1%) were lost to follow-up. We examined correlations between changes in HRQL instruments and the Children's Depression Rating Scale-Revised (CDRS-R) and assessed clinically meaningful change in multi-attribute utility HRQL measures using mean change (MC) and standardized response mean (SRM) among youth showing at least moderate (20%) improvement in depression symptomology.

RESULTS

Spearman's correlation coefficients demonstrated moderate correlation between changes in CDRS-R and the HUI2 (r = 0.38), HUI3 (r = 0.42), EQ-5D-3L (r = 0.36), SF-6D (r = 0.39), and PEDS-QL (r = 0.39) and strong correlation between changes in CDRS-R and QWB (r = 0.52) and QLDS (r = - 0.71). Effect size results are also reported. Among multi-attribute utility measures, all showed clinically meaningful improvements in the sample of youth with depression improvement (HUI2, MC = 0.20, SRM = 0.97; HUI3, MC = 0.32, SRM = 1.17; EQ-5D-3L, MC = 0.08, SRM = 0.51; QWB, MC = 0.11, SRM = 0.86; and SF-6D, MC = 0.12, SRM = 1.02).

CONCLUSIONS

Findings support the longitudinal construct validity of included HRQL instruments for the assessment of change in depression outcomes in teens. Results of this study can help inform researchers about viable instruments to include in economic evaluations for this population.