Confidence Intervals: Linking Evidence to Practice

Two previous Evidence in Practice articles described the shift in clinical research toward using between-group differences as the measure of treatment effectiveness. One key advantage to reporting the between-group difference (the effect estimate), as opposed to only providing a value from a hypothesis test, is that it tells the reader about the size of the effect. Confidence intervals give the reader critical information about the precision of an effect estimate reported in a trial. Integrating information about the likely effect and its precision, along with understanding the concept of clinical meaningfulness, helps the clinician engage patients in an informed, shared decision-making process. .