How do two meta-analyses of similar data reach opposite conclusions?

doi:10.1136/bmj.318.7187.873b

From trainee to consultant, BMJ Group offers doctors around the world tailored information, special events, learning resources and recruitment services at every step along their career path.

... by doctors, for doctors, for patients
We are open for entries!

Online learning

BMJ Learning

High-quality CME / CPD for doctors and other healthcare professionals. BMJ Learning features hundreds of accredited, peer-reviewed learning modules in text, video, and audio formats. Find out more

Courses and Qualifications

BMJ Masterclasses

BMJ Masterclasses, led by experts, help clinicians to use the latest evidence and recent guidelines in practice and meet their CPD/CME requirements. Find out more

Exam Preparation

The leading provider of online exam preparation, helping over 167,000 healthcare professionals to pass their exams. Find out more

onExamination

Search all BMJ comment articles:

From

Limit by

Access to the full text of this article requires a subscription or payment. Please log in or subscribe below.

Morten Lindbaek (morlind@vestfoldnett.no), Associate professor,
Per Hjortdahl, Professor

Department of General Practice, University of Oslo, Box 1130 Blindern, 0317 Oslo, Norway

EDITOR—In their meta-analysis Fahey et al concluded that treatment with antibiotics made no significant difference to the resolution of acute cough,1 although they found a trend favouring antibiotics. The Cochrane meta-analysis on treatment of acute bronchitis concluded that antibiotics have a modest beneficial effect.2 Eight of the nine studies extracted were the same in both meta-analyses, and 90% of the 750 patients were used in both.

How can two meta-analyses based on the same studies …