Intended for healthcare professionals

Endgames Statistical Question

Number needed to treat I

BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d2463 (Published 27 April 2011) Cite this as: BMJ 2011;342:d2463

Re: Number needed to treat I

The endgame says that answer d is the best description., where d is

d)Treatment of 23 patients with chloramphenicol will result in one less infection than if they had received the control treatment

It further adds, "The incidence of infection within 30 days of the minor skin excision was lower for the topical chloramphenicol ointment group than for the control group. Number needed to treat summarises this treatment effect, it being a measure of the benefit of treatment with chloramphenicol compared with control. The number needed to treat is the number of participants who need to be treated with chloramphenicol for one less patient to experience an infection (benefit from the intervention) than if they had received the control treatment."

Here we would like to interject that period of follow-up should also be mentioned as the observation changes with the length of follow-up. Therefore option d will be written as follows:

Treatment of 23 patients with chloramphenicol will result in one less infection than if they had received the control treatment within 30 days of follow-up.

Competing interests: No competing interests

23 July 2016
Neeru Gupta
Scientist F
Jugal Kishore
Indian Council of Medical Research
Ansari Nagar, New Delhi-110029