Major clinical guidelines ‘relying on weak evidence’

Key Australian clinical practice guidelines are based on “very weak” evidence and some include no recommendations backed by top-quality research, a study suggests.
The review of the scientific basis of 10 major clinical guidelines (see table below) used in Australia has found only 18% of the 748 recommendations they made were based on the highest level of evidence — defined by the NHMRC as a systematic review of randomised controlled trials.
And only 25% of the recommendations were based on “moderate” evidence, defined as evidence based on a single randomised controlled trial or prospective cohort study.
Some 29% were based on “low” evidence and 9% had the weakest forms of evidence, such as case series or cross-sectional studies.