Thus confidence levels are more useful than p values or 95% confidence intervals, as they give us the level of confidence, likelihood or probability that a benefit exists, and also tell us whether that benefit is clinically relevant.

Different clinicians and patients obviously will accept different magnitudes of benefit. Thus to aid decision-making, we can construct clinical significance curves.

Confidence levels have been used to analyze meta-analyses and clinical studies (refs 21-22).

21. A.M.H. Ho, A. Lee, E. Ling, A. Daly, K. Teoh, T.E. Warkentin, Agreements between the prothrombin times of blood treated in vitro with heparinase during cardiopulmonary bypass (CPB) and blood sampled after CPB and systemic protamine, Anesth. Analg. 96 (2003) 15-20.