MCQ 45: Number needed to treat

Q. A trial assessed a statin tablet compared to placebo for stroke prevention over 1 year. There were 10% of patients developing stroke in the group taking a tablet and 20% in the carotid endarterectomy group developing a stroke over the 1 year.What is the number needed to treat over 1 year to prevent 1 death?
Options:
A.1
B. 10
C. 100
D.1000

Answer: B. 10

Explanation:

Number needed to treat (NNT) is defined as number of patients being given treatment for prevention of one death.

Number need to treat: 1/Absolute risk reduction

Stroke in patients taking tablet: 10%= 0.1
Stroke in patients undergoing endarterectomy: 20%= 0.2
Absolute risk reduction: 0.2-0.1= 0.1
So, Number needed to treat to save one life: 1/0.1= 10

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ECG Spotter

What is the diagnosis? Click the button below to view answer: Show Answer

High heart rate

The patient contacts the doctor over phone with this report. Obviously anxious because of his high heart rate (199 beats per minute) as detected by ECG machine. Should he be worried about this and come to emergency department as soon as possible? Correct answer- ECG machine has calculated his heart rate incorrectly. Heart rate is around 100 beats per minute. Other findings in this ECG include ST segment elevation in anterior chest leads along with presence of Q waves, denoting old MI changes with possibly development of LV aneurysm. In such cases, ST segment elevation can persist for long periods. Now, should he come to emergency department? Not because of detection of high heart rate. But, if he is having symptoms such as shortness of breath or chest pain, he should visit emergency department. Otherwise, if he is asymptomatic, he can schedule a regular visit with his cardiologist.

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