Addressing ceiling effects in health status measures: a comparison of techniques applied to measures for people with HIV disease
IC Huang, C Frangakis, MJ Atkinson…�- Health services�…, 2008 - Wiley Online Library
Health services research, 2008•Wiley Online Library
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�…
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�…
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 (R1) 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.
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