Improving quality or shifting diagnoses? What happens when antibiotic prescribing is reduced for acute bronchitis?

Background: A quality improvement project in an academic practice demonstra ted a reduction in antibiotic prescribing for acute bronchitis. However, it was unclear whether this represented a reduction in antibiotic use or whet her physicians assigned new diagnoses to the same patients to avoid scrutin y and continue to use antibiotic therapy. Objective: To examine whether a substantial amount of diagnostic shifting o ccurred while antibiotic prescribing for acute bronchitis decreased during a 14-month period (from January 1, 1996, to February 28, 1997). Methods: All patient diagnoses of acute bronchitis, acute sinusitis, upper respiratory tract infection, and pneumonia were determined for the 14 month s of the acute bronchitis intervention. The relative distribution of patien ts among these 4 diagnostic categories was compared to determine if the per centage of patients with acute bronchitis decreased while those with acute sinusitis and pneumonia increased during the acute bronchitis intervention. Results: The percentage of patients with the diagnosis of acute bronchitis remained unchanged during the 14-month period while antibiotic use for this condition decreased from 66% of cases to less than 21% of cases. Instead o f the patients being assigned a different diagnosis such as acute sinusitis so that antibiotic prescribing would not be scrutinized, as we hypothesize d, the relative number of diagnoses for acute sinusitis compared with acute bronchitis actually declined during the 14 months. No change was noted in the relative frequency of acute bronchitis cases compared with pneumonia ca ses. Conclusion: During a 14-month period when an intervention was successful at reducing antibiotic use for acute bronchitis, there was no evidence that p hysicians shifted patients from the diagnosis of acute bronchitis to other diagnoses.