Researchers have examined in observational studies a possible influence of statins, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and β-blockers on the prevention of infections or on their outcomes. A.priori, we can suspect that biases will work in favour of chance findings, because of the motivation to publish, to publish piquant findings, and to find new niches for lucrative drugs. We should distinguish between three phases. Publication of a novel finding should raise the possibility that an intervention will work in situations other than those expected, and justify, as a second phase, the performance of rigorous, prospective, observational studies. If the results of these studies substantiate the claims for benefit, randomized controlled trials may be performed in the third phase. For all the questions examined here, we have not yet passed the threshold of evidence needed to offer patients participation in randomized controlled trials.
- ACE inhibitors
- Observational studies