Age at treatment predicts reason for discontinuation of TNF antagonists: data from the BIOBADASER 2.0 registry.

OBJECTIVES: To assess the retention rate of TNF antagonists in elderly patients suffering from chronic arthropathies and to identify predictive variables of discontinuation by inefficacy or by adverse events (AEs). METHODS: All patients treated with TNF antagonists in BIOBADASER 2.0, with a diagnosis of either RA or spondyloarthritis (SpA: AS and PsA) were included and classified as <65 (younger) or ≥65 years of age (older) at start of the treatment. Cumulative incidence function for discontinuation (inefficacy or AE) was estimated as being the alternative reason for a competing risk. Competing-risks regression models were used to measure the association between study groups, covariates and reason for discontinuation. RESULTS: A total of 4851 patients were studied; 2957 RA (2291 in the younger group and 666 in the older group) and 1894 SpA (1795 in the younger group and 99 in the older group). Retention curves were statistically differently stratified by age groups, with the SpA younger group having the largest retention rate. Competing-risks regression models showed that in the older group, AEs were the most common reason for discontinuation regardless of the diagnosis of the patient and TNF antagonist molecule, whereas in the younger group, the most common cause of discontinuation was inefficacy. CONCLUSION: In conclusion, factors predicting discontinuation of TNF antagonists due to AEs are older age and diagnosis of RA. On the other hand, younger age predicts discontinuation due to lack of efficacy.