Answering Clinical Questions of Therapy A Worksheet for Evidence-based Medicine Step 1: Define a clinical question PICO (Patient or Problem; Intervention; Comparison Intervention; Outcome) Your Question: Step 2: Find evidence Search Terms Used: Citation: Step 3: Assess Evidence Brief Summary of the Methods: Are the results likely to be valid? Question Yes No Was the assignment of patients to treatment randomized? Was the follow-up of patients sufficiently long and complete? Were the patients analyzed in the groups to which they were randomized? Were the patients and clinicians kept blind to treatment? Were the groups treated equally, apart from the experimental therapy? Were groups similar at the start of the trial? Any validity concerns? If yes, explain. The magnitude of the treatment effect: Outcome used for treatment:> Experimental treatment: Control treatment: If the study results report outcomes in numbers of patients, fill in the 2x2 table OR event rates below: Outcome Present Outcome Absent Treatment a b Control c d Please select the appropriate condition that applies to your data: - The experimental treatment reduces the risk of a bad event - The experimental treatment increases the possibility of a good event Experimental Event Rate (EER)=a/a+b % Control Event Rate (CER)=c/c+d % Number of patients in experimental group Number of patients in control group Please select the appropriate condition that applies to your data: - The experimental treatment reduces the risk of a bad event - The experimental treatment increases the possibility of a good event The experimental treatment reduces the risk of a bad event The experimental treatment increases the possibility of a good event RR (risk reduction) =EER/CER RRR (relative risk reduction) =1-RR or [CER-EER]/CER ARR (absolute risk reduction) =[CER-EER] NNT=1/ARR RBI (relative benefit increase) [EER-CER]/CER ABI (absolute benefit increase) [EER-CER] NNT=1/ABI What is the precision of the treatment effect? 95% Confidence Interval for NNT to If the study results are reported as intermediate outcomes, and you can't use the above table, report results and significance of findings below: Any concerns about assessing the evidence? If yes, explain. > Step 4: Apply the evidence to your patient Question How is your patient similar to the study population? How is your patient different? Will the differences affect the applicability of the study's result to your patient? Is the treatment available and affordable to your patient? What is the estimated cost? What are your patient's potential benefits and harms from the therapy? Based on this evidence, what would you recommend? Why? Press CTRL-P to print this worksheet. Adapted from: Sacket DL et al. Evidence-based Medicine: How to practice and teach EBM. 3rd Edition. Churchill Livingstone. 2000.