Bringing Evidence to the Bedside in Critical Care

Allan S. Detsky

Physician-in-Chief

Mount Sinai Hospital

We need information

If asked:

• We need it twice a week

• We get it from textbooks, journals and our colleagues

We really need informationIf shadowed:

• We need it twice for every 3 outpatients and 5 times for every patient

• But we rarely get what we need from the resources that we use– Colleagues– Textbooks– Journals

Ann Intern Med 1991;114:576-81

Evidence of Care Gaps

• Beta blockers in post MI patients

• Statins in post MI patients

• ACE-I in patients with CHF

• Antithrombotic therapy in patients with nonvalvular atrial fibrillation

HOW CAN WE BRIDGE THIS GAP?

Bringing evidence to the point of care• Need it within seconds if it is to be incorporated into

busy clinical rounds• Focus on users’ needs and important clinical outcomes• Our initial attempts to bring the best evidence to a busy

clinical team caring for over 200 patients per month

JAMA 1998;280:1336-8.

Kinds of Questions

1. Therapeutic Effectiveness

2. Diagnostic Accuracy

3. Prognostic Information

Therapeutic Effectiveness

For patients with health state X,

does Rx A do more good than

harm (compared to Rx B)?

Diagnostic Accuracy

Does test A help us separate those with disease from those without for patients that look like X?

Prognostic Information

For patients with health state X, was the risk of an adverse outcome over a specified period of time?

What do clinicians want on PDAs?

• Clinical bottom line from preappraised resources

• Management algorithms

• Drug dosages and interactions

• Numerical summaries of risks and benefits

• They don’t want traditional clinical practice

guidelines

Examples

Computerized decisionsupport systems (CDSS)Systems

Synopsis

Syntheses

Studies

Clinical Evidence

Cochrane Reviews

Original published articles in journals

Internet Available Resources

www.cebm.utoronto.ca

www.eboncall.co.uk

How To design 1. Learn how to recognize questions.

2. Learn how to quantify answers.

Therapeutic Effectiveness

Pc = event rate in control group

Pt = event rate in experimental group

Pc - Pt = ARD

(Pc - Pt)/Pc = PRD

Pt/Pc = RR

1 = NNT

Pc - Pt

10% - 5% = 5% = ARD

(10% - 5%)/10% = 50% = RRD

5%/10% = .5 = RR

1

10% - 5% = 20 = NNT

DIAGNOSTIC TESTS

• Sensitivity

• Specificity

• Likelihood ratios

LR > 1

LR = 1

LR < 1

Read and appraise individual

studies, systematic reviews

Then go to websites to see how

results are presented.

Next - start a simple research

project.

Medical Consults

What is the validity of a

cardiac risk index in

our patients?

• Start slowly

• Progress will take time

• It’s harder than you think