Is anaesthesia evidence-based? A survey of anaesthetic practice.

We were interested in measuring the proportion of anaesthetic interventions in routine practice that are supported by evidence in the literature. We surveyed our hospital practice, asking anaesthetists to nominate a primary problem (if any) and their chosen intervention. Each intervention was classified into one of four levels according to the strength of the evidence recovered from the literature. We found that 96.7% were evidence-based (levels I-IV), including 32% supported by randomized, controlled trials (levels I and II). These results are similar to recent studies in other specialties and refute the claim that only 10-20% of treatments have any scientific foundation.