Repeated-measures models to evaluate a hepatitis B vaccination programme

In 1985-1986, a hepatitis B vaccination programme was conducted in a Belgian institution for the mentally handicapped. A group of 97 residents was followed up for 11 years in order to characterize the long-term persistence of hepatitis B antibodies after vaccination. This paper proposes the use of linear mixed-effects models to account for serial correlation and between-individual heterogeneity in the data, while adjusting the analysis for various individual characteristics and important risk factors in the response to vaccination. We propose several model building strategies and focus on the prediction of future levels of antibodies.