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Br J Gen Pract. 2004 January; 54(498): 20–24.
PMCID: PMC1314773

A diagnostic rule for the aetiology of lower respiratory tract infections as guidance for antimicrobial treatment.

Abstract

BACKGROUND: The majority of patients with lower respiratory tract infections (LRTIs) are treated with antibiotics; some of them are unnecessary because of a viral cause. Information on prediction of the aetiology, especially in a general practice setting, is missing. AIM: To differentiate between viral and bacterial LRTI on simple clinical criteria, easily obtained at the bedside. DESIGN OF STUDY: Prospective observational study. SETTING: General practices in the Leiden region of The Netherlands. METHOD: Adult patients with LRTI were included. Standard medical history and physical examination were performed. Sputum, blood and throat swabs were collected for diagnostic tests. According to microbiological findings, patients were classified as bacterial, viral, dual infection and unknown cause. In a logistic regression model independent predictors were determined. Scoring systems were developed. The accuracies of the diagnostic rules were tested by using receiver operating characteristic (ROC) curves. RESULTS: One-hundred and forty-five patients were classified as having bacterial (n = 35), viral (n = 49), or dual infection (n = 8), or infection of unknown cause (n = 53), respectively. Independent predictors for bacterial infection were fever (odds ratio [OR] = 8.0; 95% confidence interval [CI] = 0.9 to 71.0), headache (OR = 4.3; 95% CI = 1.0 to 19.1) cervical painful lymph nodes (OR = 8.7; 95% CI = 1.1 to 68.0), diarrhoea (OR = 0.3; 95% CI = 0.1 to 1.0) and rhinitis (OR = 0.3; 95% CI = 0.1 to 0.9). As an additional independent predictor, an infiltrate on chest X-ray (OR = 5.0; 95% CI = 1.2 to 20.5) was found. The diagnostic rules developed from these variables classified the aetiology of LRTI with a ROC curve area of 0.79 (clinical score), 0.77 (simplified score) and 0.83 (extended score). CONCLUSIONS: A diagnostic rule was developed, based on information that is easy to obtain at the bedside, to predict a bacterial infection. This diagnostic rule may be a tool for general practitioners in their management of patients with LRTI.

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Supplementary Material

Supplementary table 1. Findings of bacterial infection, viral infection and unknown origin in patients with LRTI:

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Ortqvist A. Treatment of community-acquired lower respiratory tract infections in adults. Eur Respir J Suppl. 2002 Jul;36:40s–53s. [PubMed]
  • Raherison C, Peray P, Poirier R, Romand P, Grignet JP, Arsac P, Taytard A, Daures JP. Management of lower respiratory tract infections by French general practitioners: the AIR II study. Analyse Infections Respiratoires. Eur Respir J. 2002 Feb;19(2):314–319. [PubMed]
  • Graffelman A Willy, Knuistingh Neven Arie, le Cessie Saskia, Kroes Aloys C M, Springer Machiel P, van den Broek Peterhans J. Pathogens involved in lower respiratory tract infections in general practice. Br J Gen Pract. 2004 Jan;54(498):15–19. [PMC free article] [PubMed]
  • Melbye H, Berdal BP, Straume B, Russell H, Vorland L, Thacker WL. Pneumonia--a clinical or radiographic diagnosis? Etiology and clinical features of lower respiratory tract infection in adults in general practice. Scand J Infect Dis. 1992;24(5):647–655. [PubMed]
  • Macfarlane J, Holmes W, Gard P, Macfarlane R, Rose D, Weston V, Leinonen M, Saikku P, Myint S. Prospective study of the incidence, aetiology and outcome of adult lower respiratory tract illness in the community. Thorax. 2001 Feb;56(2):109–114. [PMC free article] [PubMed]
  • Macfarlane JT, Colville A, Guion A, Macfarlane RM, Rose DH. Prospective study of aetiology and outcome of adult lower-respiratory-tract infections in the community. Lancet. 1993 Feb 27;341(8844):511–514. [PubMed]
  • Woodhead MA, Macfarlane JT, McCracken JS, Rose DH, Finch RG. Prospective study of the aetiology and outcome of pneumonia in the community. Lancet. 1987 Mar 21;1(8534):671–674. [PubMed]
  • Lieberman David, Lieberman Devora, Korsonsky Igor, Ben-Yaakov Miriam, Lazarovich Zilia, Friedman Maureen G, Dvoskin Bella, Leinonen Maija, Ohana Bella, Boldur Ida. A comparative study of the etiology of adult upper and lower respiratory tract infections in the community. Diagn Microbiol Infect Dis. 2002 Jan;42(1):21–28. [PubMed]
  • Heckerling PS, Tape TG, Wigton RS, Hissong KK, Leikin JB, Ornato JP, Cameron JL, Racht EM. Clinical prediction rule for pulmonary infiltrates. Ann Intern Med. 1990 Nov 1;113(9):664–670. [PubMed]
  • Diehr P, Wood RW, Bushyhead J, Krueger L, Wolcott B, Tompkins RK. Prediction of pneumonia in outpatients with acute cough--a statistical approach. J Chronic Dis. 1984;37(3):215–225. [PubMed]
  • Melbye H, Straume B, Aasebø U, Dale K. Diagnosis of pneumonia in adults in general practice. Relative importance of typical symptoms and abnormal chest signs evaluated against a radiographic reference standard. Scand J Prim Health Care. 1992 Sep;10(3):226–233. [PubMed]
  • Farr BM, Woodhead MA, Macfarlane JT, Bartlett CL, McCraken JS, Wadsworth J, Miller DL. Risk factors for community-acquired pneumonia diagnosed by general practitioners in the community. Respir Med. 2000 May;94(5):422–427. [PubMed]
  • Hopstaken RM, Muris JW, Knottnerus JA, Kester AD, Rinkens PE, Dinant GJ. Contributions of symptoms, signs, erythrocyte sedimentation rate, and C-reactive protein to a diagnosis of pneumonia in acute lower respiratory tract infection. Br J Gen Pract. 2003 May;53(490):358–364. [PMC free article] [PubMed]
  • Farr BM, Kaiser DL, Harrison BD, Connolly CK. Prediction of microbial aetiology at admission to hospital for pneumonia from the presenting clinical features. British Thoracic Society Pneumonia Research Subcommittee. Thorax. 1989 Dec;44(12):1031–1035. [PMC free article] [PubMed]
  • Ruiz-González A, Falguera M, Vives M, Nogués A, Porcel JM, Rubio-Caballero M. Community-acquired pneumonia: development of a bedside predictive model and scoring system to identify the aetiology. Respir Med. 2000 May;94(5):505–510. [PubMed]
  • Bohte R, Hermans J, van den Broek PJ. Early recognition of Streptococcus pneumoniae in patients with community-acquired pneumonia. Eur J Clin Microbiol Infect Dis. 1996 Mar;15(3):201–205. [PubMed]
  • Melbye H, Straume B, Brox J. Laboratory tests for pneumonia in general practice: the diagnostic values depend on the duration of illness. Scand J Prim Health Care. 1992 Sep;10(3):234–240. [PubMed]
  • van den Broek PJ, Visser LG, Bohte R, Wout JV. Early diagnosis of pneumococcal pneumonia. J Antimicrob Chemother. 2000 Sep;46(3):517–517. [PubMed]
  • Holmes WF, Macfarlane JT, Macfarlane RM, Hubbard R. Symptoms, signs, and prescribing for acute lower respiratory tract illness. Br J Gen Pract. 2001 Mar;51(464):177–181. [PMC free article] [PubMed]

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