Evaluation of new drugs in daily clinical practice: anti-TNF alpha in rheumatoid arthritis patients.

Contains fulltext : 70338.pdf (publisher's version ) (Open Access)The objective of this thesis was to explore the value and the validity of data collected in daily clinical practice for drug evaluation and cost-effectiveness studies, using data collected on TNFa blocking agents in rheumatoid arthritis. First, the need for and value of information from daily clinical practice was researched. Together, the results of Chapters 3, 4 and 5 illustrated that treatment of RA patients with anti-TNFa blocking agents in daily clinical practice was different from what was expected from the performed RCTs and the guidelines developed on the basis of the RCTs. Data from a daily clinical practice registry can be used to get insight in the actual use and realized effects of medications in daily clinical practice, in contrast to the controlled setting of a RCT. Furthermore, data from clinical practice can be used to estimate the impact on the budgets in health care by implementing a new intervention in daily clinical practice. The second part of this thesis addressed the use of patient self reported measures in large daily clinical practice registries. Because the use of patient self reported measures could be very convenient to evaluate drug therapy in daily clinical practice, its was researched whether these measures could substitute more objective measures like the disease activity score. Chapters 6 and 7 of this thesis showed that patient reported measures cannot substitute objective measures of disease activity. It was shown that response shifts occurred and greatly confounded the outcomes of the patient-self-reported ratings. It was not possible to correct for response shift because it led to the paradoxical result that clinical non-responders increased significantly on a self-reported measure. It is therefore recommended to evaluate drugs in daily clinical practice also with a objective measure of disease activity.RU Radboud Universiteit Nijmegen, 07 november 2008Promotor : Riel, P.L.C.M. van Co-promotores : Adang, E.M.M., Fransen, J.174 p