Analysis of the quality of clinical trials about therapeutic research using the standard of evidence-based medicine

Abstract

To investigate the quality of clinical trials of ocular therapeutic efficacy in China in order to provide the facts to support the Evidence-Based Medicine (EBM) and improve the clinical research trials. All the articles published in Chinese Journal of Ophthalmology from 1983 to 2002 emphasizing random control trial and clinical control trial were evaluated as per EBM standard. The total number of articles for clinical therapeutic efficacy published in the past 20 years were 152, of which 35 articles (23.0%) were random control trials, and 8 (5.3%) articles were clinical control trials. The disparity of quality of research was found as follows. The method of random/half random was described in 10 articles (23.3%). Placebo-control and open-control were reported in 3 (3/43) and 9 articles (20.9%), respectively. Blinded, double-blinded, and single-blinded research was adopted in 7 (16.3%), 3 articles (7.0%), and 4 articles (9.3%), respectively. Ten articles (23.3%) reported strict diagnostic standard including inclusion and exclusion standards while 30 articles (69.8%) didn't use exclusion criteria. Follow-up visits from a few months to years was found in 30 out of 43 articles, of 25 articles (58.1%) provided detailed follow-up visit data; 19 articles (44.2%) didn't supply any information of the cases lost follow-up, only 7 articles (16.3%) reported the cause and process of the cases lost follow-up. Adverse events were not consistently reported in the articles. Not a single article estimated sample size when the study was designed. Most articles included small or medium size samples, while lacking of multi-center, large sample, randomized, double-blinded and placebo-controlled clinical trials. Statistical significance for either part or all data except P value was not indicated in 15 articles (34.9%). The indexes assessing the clinical significance of clinical therapeutic efficacy include relative risk reduction, absolute risk reduction, number needed to treat, however, these indexes were not used in all the articles. In summary, the clinical trials related to ocular therapeutic efficacy published between 1983 and 2002 were not very well designed and the accuracy and the reliability of the results were greatly affected. Therefore, it is imperative to improve the quality of the research by enhancing the design and analysis of the research in future.