Infoxication: How many journals do you need to read?

How many journals does a clinician need to read to find all the trials in their speciality? We recently looked at a dozen specialities, and neurology appeared the worst [2]. There were 2770 neurology relevant trials in 2009 which were scattered across 896 journals (about one sixth of the 5,632 journals currently indexed for MEDLINE). Of course, no neurologist could, or would want to, read all 2,770 trials, but to find even quarter of these would require an estimated 29 journals, and to find half would require 114 journals. And this includes neurology specialist journals, general medical journals, and journals of related specialities such as rehabilitation. 

Because systematic reviews summarize a number of trials, they are less scattered: 547 reviews in 292 journals. But still many more journals than the typical two to six journals a clinician will receive (and maybe read some of). So the traditional process of reading the local general medical journal and a couple of speciality ones will mean many important developments are missed. A couple of options are McMaster’s ACCESSSS—a free but carefully filtered site that provides updates on recent high quality studies; another evolving option is PubMedHealth, which aims to have in one place, in a single search, most systematic reviews (not restricted to Medline-indexed journals). Each clinician and speciality group will need to organise their own processes to address this scatter of research information, but the first step is awareness there is a problem.