How to apply results from randomized trials and systematic reviews to individual patient care

A clinician may apply the results from randomized controlled trials and population-based cohort studies to the management of an individual patient to determine whether the patient will achieve more benefit than harm from the intervention. From the data the clinician should determine what are the benefits and harms of the intervention, whether there are any variations in the relative treatment effect, whether the treatment effect varies with different baseline risks of disease in untreated patients, what are the predicted reductions in absolute risk of disease for individuals and whether the benefits outweigh the risks for their patient. If the patient is at a low risk of the outcome, the harms of therapy may not justify its use to prevent or treat the disease. However, if the patient is at a high risk of developing the outcome, he or she is likely to gain more benefit than harm from the therapy.