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RESEARCH: I Petersen, A M Johnson, A Islam, G Duckworth, D M Livermore, and A C Hayward Protective effect of antibiotics against serious complications of common respiratory tract infections: retrospective cohort study with the UK General Practice Research Database BMJ 2007; 0: bmj.39345.405243.BEv1 [Abstract] [Full text]

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Antibiotic treatment for chest infections in the elderly. Why not consider chronic obstructive pulmonary disease?

Carl Llor, Marc Miravitlles   (30 October 2007)

Selection bias

James meade, BT746NN   (4 December 2007)

Definition of "Chest Infection"

Glenn L. Kashan   (1 January 2008)

Antibiotic treatment for chest infections in the elderly. Why not consider chronic obstructive pulmonary disease? 30 October 2007
Carl Llor, Family physician Primary Health Care Jaume I, Tarragona (Spain), Marc Miravitlles Send response to journal: Re: Antibiotic treatment for chest infections in the elderly. Why not consider chronic obstructive pulmonary disease?	We read this study on the protector effect of antibiotics on the appearance of complications in chest infections with great interest (1). This study initially justifies not prescribing antibiotics in upper respiratory tract infections and pharyngitis, but doing so in cases of acute bronchitis, or, as the authors state, in chest infections, mainly in patients over the age of 65 The results of this study may further induce the prescription of antibiotics in this age group, since the authors demonstrate that only 39 patients required treatment to avoid a case of pneumonia. To prevent excessive use of antibiotics in the community, it would be useful to identify a subgroup of patients with chest infection and over 65 years of age who would most benefit from antibiotic treatment. In this respect, patients with chronic bronchial disease such as chronic bronchitis, and particularly chronic obstructive pulmonary disease (COPD) appear to be an obvious target. The prevalence of COPD in individuals over 65 in the general population is very high, even higher than 20% (2) and the incidence of pneumonia in patients with COPD and symptoms of chest infection (so-called exacerbations of COPD) is slightly above 10% (3). The presence of a chronic bronchial disease may even be a better predictor of the need for antibiotics than age, since COPD patients themselves have an increased risk of pneumonia and associated mortality (4), and impaired lung function is a known risk factor for relapse (5) and hospitalisation (6) following chest infection in patients with COPD. Therefore, by analysing the impact of COPD and/or chronic bronchitis in the outcomes in their database, the authors could potentially address whether there are differences in the risk of pneumonia during the first month after treatment with or without antibiotics for chest infection according to the presence of underlying COPD. With these results, it would be possible to discriminate between patients older than 65 years with or without chronic bronchial disease and decide the prescription of antibiotics for chest infections accordingly, if the risk of complications is, as expected, related to the presence of baseline COPD. In contrast, it would be very helpful to demonstrate whether patients with chest infection under 65 years without chronic bronchitis or COPD do not have an increased risk of complications without antibiotic treatment and spare the use of antibiotic in this population. According to the clinical trial by Stott et al (7), in patients with acute bronchitis even in presence of purulent sputum, antibiotic treatment was not more effective than placebo. The variable of chronic bronchial disease, particularly in the elderly, may help to better identify those more at risk of a poor outcome or complications after chest infection and provide guidelines to reduce the inappropriately high consumption of antibiotics in the community. References: 1. Petersen I, Jonson AM, Islam A, Duckworth G, Livermore DM, Hayward AC. Protective effect of antibiotics against serious complications of common respiratory tract infections: retrospective cohort study with the UK General Practice Research Database. BMJ 2007 Oct 18; doi:10.1136/bmj.39345.405243.BE 2. Pena VS, Miravitlles M, Gabriel R, Jiménez-Ruiz CA; Villasante C, Masa JF, et al. Geographic variations in prevalence and underdiagnosis of COPD: results of the IBERPOC multicentre epidemiological study. Chest 2000;118:981-9. 3. Emerman CL, Cydulka RK. Evaluation of high-yield criteria for chest radiography in acute exacerbation of chronic obstructive pulmonary disease. Ann Emerg Med 1993;22:680-4. 4. Restrepo MI, Mortensen EM, Pugh Ja, Anzueto A. COPD is associated with increased mortality in patients with community-acquired pneumonia. Eur Respir J 2006;28:346-51. 5. Niewoehner DE, Lokhnygina Y, Rice K, Kuschner WG, Sharafkhneh A, Sarosi GA, et al. Risk indexes for exacerbations and hospitalizations due to COPD. Chest 2007;131:20-8. 6. Miravitlles M, Guerrero T, Mayordomo C, Sánchez-Agudo L, Nicolau F, Segú JL on Behalf of the EOLO Study Group. Factors associated with increased risk of exacerbation and hospital admission in a cohort of ambulatory COPD patients: a multiple logistic regression analysis. Respiration 2000;67:495-501. 7. Stott NC, West RR. Randomised controlled trial of antibiotics in patients with cough and purulent sputum. Br Med J 1976;2:556-9. Competing interests: None declared
Selection bias 4 December 2007
James meade, GP Lakeside Medical Practice, Enniskillen, N. Ireland, BT746NN Send response to journal: Re: Selection bias	Dear sirs, I found a sgnificant selection bias in that I feel those prescribed antibiotics (group A) were more likley to differ clinically (in terms of severity of symptoms and signs) than those not prescribed antibiotics (group B). Ideally those prescribed antiobiotics (group A) should instead have been randomised in a RCT to a prescribed antibiotic group (A1) and non- prescribed group (A2) in order to answer your question. Group B should be excluded as it is a different clinical group (less severe symptoms and signs). So should this study influence my prescribing? No - You argue a Double blind RCT is too difficult to do, but your review really could be misleading and in my opinion your review does not answer whether antibiotics prescribed in primary care reduce complications or not. Dr James Meade MRCGP and practicing GP Competing interests: None declared
Definition of "Chest Infection" 1 January 2008
Glenn L. Kashan, Assistant Professor, Internal Medicine Albert Einstein College of Medicine, Beth Israel Medical Center, New York, NY 10003 Send response to journal: Re: Definition of "Chest Infection"	Dear Sirs, Your findings are provocative, particularly for the case of "Chest Infections." I would be eager to apply these findings in my practice if I could figure out a way to do so. The main barrier I see in such application is a lack of understanding on my part as to what constitutes a "Chest Infection." While I note in the article that "Chest Infection" is defined by reference to Read and OXMIS codes, I do not know how these codes translate into the findings I see in clinical practice. Perhaps my confusion is a result of different terminology used in Britain and the United States. While clearly judgments are somewhat subjective as to whether an illness is of one type or another, I would appreciate any guidance that you might have as to what specific clinical findings are generally associated with a "Chest Infection," as differentiated from an "Upper Respiratory Infection." Is a cough a requirement for a "Chest Infection" diagnosis, are rhonchi, etc. ? Thank You, Glenn Kashan, MD Competing interests: None declared