Pragmatic Analysis of Longitudinal Data on Disease Activity in Systemic Lupus Erythematosus

The multiple clinical manifestations of systemic lupus erythematosus are a challenge to rheumatologists managing patients with the disease, and there is a need to better understand predictors of disease activity in order to improve and standardize therapy and prevent the development of permanent damage. In this article, we present the analysis of a clinical database for patients with lupus. The database consists of data collected on 440 patients over a period of 10 years. The analysis is based on logistic regression methodology with outcomes defined at the times of clinic visits and develops an approach to examine the interrelationships between disease activity in different systems. The usefulness of separate logistic regressions with dynamic covariates for the analysis of multinomial panel data is illustrated and the efficiency of the approach relative to modeling disease activity in continuous time is investigated.