Over the years many attempts have been made to address these issues, improve quality and processes, and reduce the burden on Review Groups (see Figure 2). Most were only partially successful, and some have added complexity to the current model; the creation of Networks is an example of this. The Network model was intended to improve the quality and relevance of reviews through standardizing editorial processes and prioritization, providing quality assurance, sharing good practice, and promoting greater collaboration between Review Groups. At a cost of approximately £0.8m per year (to run the Networks) these objectives were only partially achieved.
There was some improvement in the quality of high priority reviews but overall they proved a weak mechanism for improving relevance and quality generally, and usability of all reviews, because lack of accountability of Review Groups to Cochrane remained. There is no evidence that Networks helped to address efficiency of process or contributed to reducing the length of development for reviews, indeed, the median time from published protocol to complete review has been approximately three years since 2018.