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Clerkship Program - Influenza Case Study

Step 3: Assess the Evidence

Are the results likely to be valid?

Criteria 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 the groups similar at the start of the trial?

What was the Magnitude of the treatment effect?

Outcome Present Outcome Absent
Treatment a b
Control c d

Since the treatment in this study reduces the possibility of a bad event:

Calculate the EER:

Calculate the CER:

Calculate the RR:

Calculate the RRR:

Calculate the ARR:

Calculate the NNT:

What is the precision of the treatment effect?

Calculate the Confidence Interval for the NNT:
EER (Experimental Event Rate) %
CER (Control Event Rate) %
Number of patients in experimental group
Number of patients in control group

95% CI for NNT to
Explanation of Answer:

Proceed to Step 4: Apply the Evidence