139 Overdiagnosis of the bacterial aetiology of the acute exacerbations of chronic obstructive pulmonary disease: discrepancies among current guidelines

Abstract

Objectives Our group has identified five Spanish bodies who have recently issued guidelines suggesting when an acute exacerbations of chronic obstructive pulmonary disease (COPD) has a bacterial aetiology. All these recommendations are different as GOLD 2014 considers giving antibiotics when two or three Anthonisen criteria are present, GesEPOC 2014 (followed mainly by pneumologists) only considers sputum colour change while semFYC 2017 (society of family doctors) considers purulent sputum or in cases of CRP ≥40 mg/L. Another guideline (Aljarafe 2012) considers only type 1 exacerbations for milder cases and type 2 when purulent sputum is present in moderate COPD. According to the latest European Respiratory Society (ERS, 2017) guideline states that patients with purulent sputum and the presence of other considerations (e.g. disease severity) most likely to benefit from antibiotic treatment. A sample of general practitioners (GP) was selected to compare the use of antibiotics prescribed with the current clinical guidelines. Method GPs from eight Spanish areas were invited to participate. They were requested to register individuals aged 40 or older with acute exacerbations of COPD over a 3 week period from January to March 2015 by means of a simple chart providing relevant information about COPD exacerbations. On this sheet, the GP attending the patient noted different specific parameters of medical care, including the age and gender of the patient, the number of days with symptoms, presenting signs such as fever, increased cough, increase of dyspnoea, increase in sputum volume and purulence of sputum, infection severity on a 5-item scale, performance of chest radiograph, pulse oximetry and C-reactive protein (CRP) rapid tests, antibiotic treatment or not, whether the patient requested an antibiotic, significant comorbidities and referral to another healthcare setting. This information was compared to the five different guidelines. Results A total of 238 GPs registered 426 episodes of acute COPD exacerbations. In terms of symptoms and signs, the most frequently reported among patients was the presence of increased cough, observed in 83.8% of the cases, followed by increased sputum volume (65.7%), increase of breathlessness (61.7%), and purulent sputum (42.3%). Twenty-one patients were referred to hospital (4.9%). A total of 338 patients were treated with antibiotics (79.3%). GPs who performed a CRP procedure prescribed fewer antibiotics than those who did not use this rapid test (78% vs 82.1%, NS). If GPS had followed the latest guidelines (GOLD 2014, GesEPOC 2014, semFYC 2017, Aljarafe 2012 and ERS 2017), they would have prescribed antibiotics to 57%, 42.3%, 43.4%, 37.3% and 59.2%, respectively. Conclusions GPs clearly overestimate the bacterial aetiology of COPD exacerbations as they prescribed antibiotics to nearly 80% of the patients. Conversely, current guidelines recommend that antibiotics should have been prescribed in a percentage ranging from 37.3% to 59.2%. Distinguishing viral from bacterial aetiology based on only clinical criteria is difficult. This is reflected in this study as GPs who do not use CRP rapid tests are more liable to prescribe antibiotics. Although one of the guidelines on acute exacerbations of COPD recommends the utilisation of CRP their use is negligible in Spain. Clinical practice guidelines should serve as recommendations to help health care providers reduce ineffective or inappropriate therapies and make better decisions regarding patient care. However, the five guidelines found in our country are different and use different criteria as to when a bacterial aetiology should be suspected.