AER-COMED (sub-project 5): The risk of adverse events from drug treatment in patients over 70 years of age with rheumatoid arthritis

Subproject 5 focuses on the treatment of older patients (>70 years) with rheumatoid arthritis. A first analysis will investigate whether there are differences in drug treatment compared to younger patients. This will be done by looking closely at treatment patterns, particularly the prescription of glucocorticoids, NSAIDs, opioids and other analgesics.

A further analysis will examine the risk of infection in the group of patients aged >70 years on various DMARDs, with a particular focus on glucocorticoids, which, as previous analyses have shown, are used in a predominant proportion of patients in this age group.

The data are from the long-term observational study RABBIT, which has been running since 2001. Currently (as of 01/2025), the RABBIT cohort contains data on approximately 2,000 patients over 70 years of age and 21,000 patients who are younger or exactly 70 years of age (remaining study population).

To compare different treatments, regression models are run and weighted using propensity score methods (inverse probability of treatment weighting, IPTW). Inverse probability of censoring weighting (IPCW) is also used to correct for selective attrition; both weightings are combined. Marginal structural models from causal inference will be used for infection analysis where the number of events allows. Time strata will be used in the analyses to account for the changing reality of care during the existence of RABBIT.