Abstract
Objectives. To compare different approaches to address ceiling effects when predicting EQ-5D index scores from the 10 subscales of the MOS-HIV Health Survey. Study Design. Data were collected from an HIV treatment trial. Statistical methods included ordinary least squares (OLS) regression, the censored least absolute deviations (CLAD) approach, a standard two-part model (TPM), a TPM with a log-transformed EQ-5D index, and a latent class model (LCM). Predictive accuracy was evaluated using percentage of absolute error (R 1) and squared error (R2) predicted by statistical methods. Findings. A TPM with a log-transformed EQ-5D index performed best on R1; a LCM performed best on R2. In contrast, the CLAD was worst. Performance of the OLS and a standard TPM were intermediate. Values for R1 ranged from 0.33 (CLAD) to 0.42 (TPM-L); R2 ranged from 0.37 (CLAD) to 0.53 (LCM). Conclusions. The LCM and TPM with a log-transformed dependent variable are superior to other approaches in handling data with ceiling effects.
Original language | English (US) |
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Pages (from-to) | 327-339 |
Number of pages | 13 |
Journal | Health services research |
Volume | 43 |
Issue number | 1 P1 |
DOIs | |
State | Published - Feb 2008 |
Keywords
- Ceiling effects
- HIV
- Health-related quality of life
ASJC Scopus subject areas
- Health Policy