Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài:Efficacy assessed in follow-ups of clinical trials: methodological conundrum. | Landewe Arthritis Research Therapy 2010 12 132 http content 12 4 132 EDITORIAL L_ Efficacy assessed in follow-ups of clinical trials methodological conundrum Robert BM Landewe See related research by Rantalaiho etal. http content 12 3 R122 Abstract Increasingly we see papers describing the longterm follow-up results of randomised clinical trials. Sometimes like the article by Rantalaiho and colleagues in the previous issue of Arthritis Research Therapy the follow-up extends to more than 10 years. It is not uncommon that authors of such articles describe their results as a comparison of the original treatment groups in the original randomised clinical trial. Methodologically such a comparison is fallible for several reasons. In this editorial two important sources of bias that may jeopardise the results of such followup studies are discussed confounding by indication and confounding by trial completion. Long-term follow-ups of randomised clinical trials are a contradictio in terminis. With this rather bold statement I do not mean that such studies are impossible to conduct. Rantalaiho and colleagues have proven with the publication of the 11-year follow up of their world-famous Fin-RACo trial that dedicated investigators and patients who believe in the goals of the study can create a dataset that is insurmountable in terms of wealth from which we can learn a lot about the long-term fate of patients with rheumatoid arthritis RA 1 . The authors have carefully analysed the available radiographic data they have investigated important long-term outcomes such as mortality and joint-replacement surgery and they have appropriately modelled longitudinal data. Their conclusion that early aggressive therapy with combinations of conventional disease-modifying antirheumatic drugs including corticosteroids pays off in terms of long-term radiographic and clinical benefits is credible. And their Correspondence
