The specialty of Infectious Diseases: More art than science?

The November 15 issue of Clinical Infectious Diseases has an interesting paper that evaluates the quality of the IDSA clinical practice guielines. The authors reviewed 44 current guidelines available at the time of the study, which consisted of 4,182 component recommendations. Over half (55%) of the recommendations were based on level III evidence (expert opinion or descriptive studies), and only 15% were based on level I evidence (at least 1 randomized controlled trial). Of note, when revised guidelines were compared to their corresponding original versions, there was a 12% relative increase in recommendations backed by level I evidence, though that was only a 1.6% absolute increase. Just goes to show you that infectious diseases is still in its infancy as a specialty and the unknown remains vast. This must be why I often feel like I am flying by the seat of my pants.