Intended for healthcare professionals

Student Education

The evidence based clinician: part 3--applying evidence to your patient

BMJ 2002; 325 doi: (Published 01 November 2002) Cite this as: BMJ 2002;325:0211410
  1. Christopher Ball, project director, Centre for Evidence Based Medicine1
  1. 1Oxford OX3 7JX

In the third part of his series, Christopher Ball looks at how to apply evidence to patients, by focusing on treatment decisions

Previously, I looked at how to ask clinical questions and where and how to find the answers rapidly. In this part, I introduce some important concepts of evidence based medicine that matter to busy clinicians and consider how to customise the evidence found to the individual needs of your patient. This is a complex area needing both clinical expertise and an understanding of the patient's values and expectations--just one of the many steps in the clinical decision making process.

Limitations of evidence

Firstly, it is important to understand what evidence can and cannot tell you. Above all, it cannot tell you how to manage your patient. Studies report the effects on a group of patients, so particularising information needs careful consideration of individual factors. Also, studies are unlikely to offer guidance on the nuances of management--you can only learn this at the bedside. It is probably best to treat evidence as useful facts and figures that can help you manage your patient more effectively, rather than decrees set in stone. Factors such as the facilities available, what your consultants think, and what management wants can easily prevent implementation of the best quality evidence.

Equally try to avoid “evidence nihilism”; in other words, avoid deciding not to apply some evidence to your patient simply because they are not exactly like the participants in the study. Is your patient so different from the patients in the study that you should discard the evidence and start searching again? In reality, this rarely happens, and usually only when patients have different pharmacokinetics or other comorbidity or social factors that prevent treatment.

Although much of what we do is evidence based (81% of primary care interventions; …

View Full Text

Log in

Log in through your institution


* For online subscription