The private life of systematic reviews

Hardly a month goes by without a report in the medical literature on some aspect of systematic review methodology. The articles address the parts of a systematic review that come under the scientific spotlight in the methods section of a report; they represent the public face of a systematic review.

The conduct of a systematic review, however, depends also on enlisting the cooperation of the trialists who provide the data. In contrast to the public nature of the more technical aspects of a systematic review, details of these interpersonal interchanges are never mentioned in the published report. We argue that a closer look at these interpersonal interactions raises important questions for the evolving science of reviewing the medical literature.

Personal communication with trialists is an important way of ensuring that trials are not missed in a systematic review. Trialists can be sent a list of the trials found to date and asked if they know of any others. Most investigators are pleased to help: “Thank you for your letter …. I enclose a list of relevant studies, some of which are controlled.”

Some investigators, however, recognise that trial identification is the most arduous part of a systematic review and see this as freeloading: “You asked me in your letter whether there are other …