Does acute bronchitis really exist? A reconceptualization of acute viral respiratory infections

Considerable overlap exists in patient presentations and physical findings in viral upper respiratory tract infections (URIs) and acute bronchitis. Our goal was to determine whether there are any clinical cues that could help physicians differentiate between these 2 conditions. We performed a retrospective chart audit on 135 patients who had been given a diagnosis of acute bronchitis and a random sample of 409 patients with URIs over a 2.5-year period. Patient and provider characteristics, patient symptoms, and physical findings were compared with bivariate analyses and then entered into a logistic regression model. In bivariate analyses, a number of demographic variables, symptoms, and signs were associated with acute bronchitis. Multivariate analysis showed that the strongest independent predictors of acute bronchitis were cough (adjusted odds ratio [AOR]=21.12; 95% confidence interval [CI], 6.01-74.26), and wheezing on examination (AOR=12.16; 95% CI, 5.39-27.42). Nausea was the strongest independent predictor that the diagnosis would not be acute bronchitis (AOR=0.01; 95% CI, 0.01-0.85). However, there was considerable overlap between the 2 conditions, and the logistic model explained only 37% of the variation between the diagnoses. We hypothesize that sinusitis, URI, and acute bronchitis are all variations of the same clinical condition (acute respiratory infection) and should be conceptualized as a single clinical entity, with primary symptoms related to different anatomic areas rather than as different conditions.