Beating Bias: the history of meta-analysis and systematic reviews

This PhD project is linked to a larger research project on the history of laboratory-clinic relations in medical research, or what today is known as ‘translational Medicine’. An important aspect of translational medicine is the evaluation of therapeutic interventions by means of randomised clinical trials, meta-analysis and systematic review. The PhD project focuses on the history of these approaches and especially of meta analyses.

An early form of meta-analysis, a statistical method that allowed the combination of observations from several clinical studies was developed at the beginning of the twentieth century by Karl Pearson, to evaluate the effectiveness of inoculation against typhoid fever among soldiers (O’Rourke 2007). However, meta-analysis and the idea of standardized, systematic reviews are more commonly associated with the work of the Cochrane Collaboration (founded in 1993 by Sir Iain Chalmers and about 70 international collaborators). There are also close links with what the pioneers of Evidence Based Medicine (EBM) at McMaster’s University in Hamilton, Canada termed the ‘critical appraisal’ of medical literature (Daly 2005, Levin 2001).

The Cochrane Collaboration, an association of volunteers, is named after the epidemiologist Archie Cochrane (1909-1988), the charismatic long-term director of the MRC Epidemiological Research Unit located in a South Wales coalmining community in the Rhondda valley. Cochrane never organised a randomised controlled trial himself, but a book he published in 1972 on Effectiveness and Efficiency in the health services inspired Chalmers, a young obstetrician, to think about methods that helped assure that limited resources in health care were used most effectively. The first step, he thought, was to conduct reliable research to identify medical interventions that do more harm than good. In 1974 Chalmers began to set up a comprehensive register of all randomized clinical trials in perinatal medicine, developing the methods that the Cochrane Collaboration later extended to other fields. Chalmers and his colleagues pioneered the use of information technology for compiling and communicating their reviews, well before the World Wide Web or even email were available. Cochrane, by then retired, supported their work and in 1979 proposed that each medical specialty should provide up-to-date critical summaries or relevant trials in its field. The Cochrane Collaboration was launched five years after Cochrane’s death, when Chalmers thought he had achieved what he could in the perinatal field, and with some support from the new UK National Health Service Research and Development Programme. The PhD student will study the history of the Cochrane Collaboration, focusing on selected Cochrane Centres and disease groups as case studies in the broader history of meta-analysis and the standardized, systematic review approach.