Patients in daily rheumatological care differ in their individual risk profiles from participants in randomized controlled trials (RCT), e.g. due to comorbidities and age. Transferring results from RCTs into routine daily practice is therefore limited.
The aim of this study was to evaluate the contribution of observational studies for decision-making in routine rheumatology practice.
We used data from the German biologics register RABBIT which includes patients with rheumatoid arthritis (RA) when starting synthetic (s) or biologic (b) disease-modifying antirheumatic drugs (DMARD). They are observed for at least 5 years. Comorbidities and clinically relevant aspects (e.g. history of malignancies) are reported at baseline and adverse events at regular follow-up.
Only one out of three patients treated with bDMARDs in RABBIT would have fulfilled the inclusion criteria of the respective pivotal study. Register data enabled developing a risk scoring model which evaluates the individual risk of a patient for serious infections depending on different risk factors and the respective DMARD treatment. Open online access to the score provides the possibility of risk estimation for all rheumatologists. Further results identified long-standing high disease activity as a dominant risk factor for a worsening of prevalent comorbidities. In patients with heart failure it was shown that effective treatment and control of disease activity with tumor necrosis factor (TNF) inhibitors was more likely to be protective than harmful.
Observational studies contribute essentially to the assessment of individual risks of patients. The results provide valuable information to support clinical decision-making and therefore strengthen the evidence when treating patients of higher age or with existing comorbidities.