Abstract
Objective. To assess the longitudinal validity of widely used preference-weighted measurement systems for economic studies of intervertebral disk herniation (IDH). Methods. Using data at baseline and 1 year from 1000 Spine Patient Outcomes Research Trial (SPORT) participants with IDH and complete data, the authors considered the EQ-5D with UK and US values (EQ-5D-UK and EQ-5D-US), 2 versions of the Health Utilities Index (HUI3 and HUI2), the SF-6D, and a regression-estimated quality of well-being score (eQWB). Differences in mean change scores (MCS) were assessed using signed rank tests, and Spearman correlations were calculated for change scores by system pairs. Using the Oswestry Disability Index, symptom satisfaction, progress rating, and self-perceived health ratings as criterion measures, the authors tested for trend in MCS across levels of change in criteria. They calculated floor and ceiling effects, effect size (ES), standardized response mean, and minimal important difference estimates. Results. All systems demonstrated linear trends with external criteria and moderate to strong correlations between systems. However, differences in performance were evident. SF-6D and eQWB were most responsive (ES: 1.9 and 2.3, respectively), whereas EQ-5D-US and EQ-5D-UK were least responsive (ES: 1.23/1.20). Ceiling and floor effects were noted for all systems within key dimensions and for EQ-5D-UK and EQ-5D-US for overall score. MCS ranged from 0.40 (0.38) for EQ-5D-UK to 0.13 (0.09) for eQWB and differed significantly, except between EQ-5D-US and HUI2. Conclusions. This research supports the validity of all systems for measuring change in persons with IDH, without finding a clearly superior system. The unique characteristics of each system revealed in this study should guide system choice.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 270-280 |
| Number of pages | 11 |
| Journal | Medical Decision Making |
| Volume | 31 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 2011 |
Funding
Support for this research was provided by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (U01-AR45444-01A1 and P60-AR048094-01A1) and the Office of Research on Women’s Health, the National Institutes of Health, the National Institute of Occupational Safety and Health, the Centers for Disease Control and Prevention; and a New Investigator Fellowship Training Initiative grant from the Foundation for Physical Therapy. The authors would like to acknowledge funding from the following sources: grant number F32HD056763 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development or the National Institutes of Health.
Keywords
- Cost-effectiveness analysis
- Cost-utility analysis
- Economic evaluation
- Health state preferences
- Health status indicators
- Quality of life
- SPORT
- Scale validation
- Spine diseases
- Utilities and valuation
ASJC Scopus subject areas
- Health Policy
