Evidence ratings…

The algorithms presented in these chapters are based on available evidence. The degree of evidence available to support the decision tree in the algorithm is rated according to the following scale:

No rating: there are no published studies with original data to investigate a direct relationship between an intervention and outcome.

One star (*): There is qualitative (directional) evidence but insufficient quantitative evidence to establish a statistical relationship between intervention and outcome. Suggestive evidence refers to data from descriptive studies, case reports, and other study designs/reports that include original data.

Two stars (**): Quantitative data indicate a statistically significant relationship between an intervention and an outcome, and qualitative data are supportive and concur. Supportive evidence refers to data from randomized and controlled non-randomized comparative studies.