Background Little evidence exists about what contributes to successful medical research, an increasingly important issue in an era of limited research budgets. This study examined predictors of productivity of Swiss medical research.
Methods Principal investigators of clinical research projects funded by the Swiss National Science Foundation between 1990 and 1994 were surveyed by mail. They provided information about the research question, whether changes were made to the protocol and why, their assessment of the importance of results for science and for public health, and additional funding of the project. The amount of the grant and the project priority score were obtained from the Foundation. Indicators of scientific productivity were the number of peer-reviewed articles and the summed impact factor per grant.
Results The size of the grant predicted scientific output (number of articles and summed impact factor), but the marginal return decreased with the total sum awarded. The award of a continuation grant by the same agency and additional funding from other sources were also positively linked with productivity. In addition, the initial priority rating of the project by the funding agency’s scientific committee and the assessment of scientific importance of the results by the principal investigator were also independently associated with productivity. Finally, modifications of the initial research plan in response to new scientific opportunities were linked with greater productivity, whereas modifications induced by technical or other difficulties were associated with lower productivity.
Conclusions Productivity in medical research, measured by peer-reviewed articles produced, requires adequate resources and ability to respond to new scientific challenges, and it can be anticipated by peer-review.