Factors associated with relapse after ambulatory treatment of acute exacerbations of chronic bronchitis

This study aimed to identify the risk factors for relapse after ambulatory treatment of acute exacerbations of chronic bronchitis (AECB) that can easi ly be used in a primary care setting. Data were prospectively collected on 2,414 ambulatory patients with AECB fr om 268 general practices located throughout Spain. A multivariate model to identify risk factors independently associated with failures was developed and validated from the information recorded at the inclusion visit and at 3 0-days follow-up visit. A total of 507 patients relapsed (21%); of these, 84 required admission (16 .5%). The multivariate model for prediction of the risk of relapse included 2,414 cases: 1,689 for the developmental sample and 725 in the validation sample. The model obtained contained three readily-obtainable variables: is chaemic heart disease (odds ratio (OR)=1.63; 95% confidence interval (CI)=1 .07-2.47), degree of dyspnoea (OR=1.31; 1.14-1.50) and number of visits to the general practitioner the previous year (OR=1.07; 1.04-1.10). The model calibrated well in developmental and validation samples (goodness-of-fit te sts: p = 0.295 and p = 0.637, respectively). Severity of the exacerbation w as not associated with increased risk of relapse in either univariate or mu ltivariate analysis. The present results suggest that baseline characteristics of the patients s uch as degree of dyspnoea, coexisting ischaemic heart disease and number of previous visits to the general practitioner for respiratory problems are s trongly associated with increased risk of relapse after ambulatory treatmen t of acute exacerbations of chronic bronchitis. In contrast, exacerbation s everity was not associated with clinical failure. Guidelines for management of acute exacerbations of chronic bronchitis should consider such risk fac tors and advocate intensive broad spectrum treatment and closer follow-up o f patients exhibiting them.