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Dr Chris Cates' EBM Website

Treatment of common infections

The National Prescribing Centre in Liverpool has recently published a Bulletin on the management of common infections in primary care which you may find a useful resource. You can find the summary page at

http://www.npc.co.uk/MeReC_Bulletins/MeReC_Bulletin_Vol17_No3_Intro.htm

The bulletin contains sections on

The key points from each document are also available in one print-friendly document, which can be downloaded and used as a reminder.

The article on acute sinusitis uses the Cochrane review of antibiotic treatment with Visual Rx graphics to demonstrate the number of patients who need to be treated for one extra to have a clinical cure. This works out as an NNT of six. To download the whole article as a pdf file follow the link to acute sinusitis.

There is also a useful meta-analysis of antibiotics for acute otitis media using individual patient data that was published in the Lancet in October 2006. The abstract is at the bottom of this page.

The aim of the paper was to try identify which children would be most likely to benefit from antibiotics, and data was available from 1643 children aged six months to 12 years. They concluded that an observational policy (in other words not using antibiotics straight away) was justified in most children with mild disease, but they did find a greater benefit from antibiotics in children under 2 years of age who had bilateral acute otitis media, and in children over 2 years with bilateral otitis media.

A discharging ear was also a marker of persistent pain or fever at 3-7 days, and more benefit was seen from antibiotics when discharge was present. The NNT for antibiotic treatment in children with a discharging ear was three:

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In contrast the NNT for those without discharge was eight:

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Rovers MM, Glasziou P, Appelman CL, et al. Antibiotics for acute otitis media: a meta-analysis with individual patient dataLancet 2006; 368: 1429-1435

Summary

Background

Individual trials to test effectiveness of antibiotics in children with acute otitis media have been too small for valid subgroup analyses. We aimed to identify subgroups of children who would and would not benefit more than others from treatment with antibiotics.

Methods

We did a meta-analysis of data from six randomised trials of the effects of antibiotics in children with acute otitis media. Individual patient data from 1643 children aged from 6 months to 12 years were validated and re-analysed. We defined the primary outcome as an extended course of acute otitis media, consisting of pain, fever, or both at 3 to 7 days.

Findings

Significant effect modifications were noted for otorrhoea, and for age and bilateral acute otitis media. In children younger than 2 years of age with bilateral acute otitis media, 55% of controls and 30% on antibiotics still had pain, fever, or both at 3 to 7 days, with a rate difference between these groups of −25% (95% CI −36% to −14%), resulting in a number-needed-to-treat (NNT) of four children. We identified no significant differences for age alone. In children with otorrhoea the rate difference and NNT, respectively, were −36% (−53% to −19%) and three, whereas in children without otorrhoea the equivalent values were −14% (−23% to −5%) and eight.

Interpretation

Antibiotics seem to be most beneficial in children younger than 2 years of age with bilateral acute otitis media, and in children with both acute otitis media and otorrhoea. For most other children with mild disease an observational policy seems justified.