Our findings regarding patient expectations for antibiotics were surprising. On univariate analysis, we found that patient expectation for an antibiotic was a predictor of antibiotic prescribing. However, contrary to widely held beliefs, patient expectation of an antibiotic prescription was not an independent predictor of antibiotic prescribing in our study. After adjusting for other related factors in the logistic regression model, antibiotics were prescribed as frequently for those not expecting one as for those expecting one. We believe that patient expectation may be a surrogate marker for “having received an antibiotic in the past for a similar illness and had good results.” Thus, patient expectation is driven by past physician behavior in prescribing antibiotics. Other researchers have noted an association between patient expectation and antibiotic prescribing,15,16 but they did not adjust for other factors associated with both patient expectation and antibiotic prescribing.
Also, in the absence of the 5 physical findings noted above (rales or rhonchi, sinus tenderness, postnasal drainage, purulent nasal discharge, and clear nasal discharge), patient expectation of an antibiotic and receiving an antibiotic in the past for a similar illness does not appear to affect clinicians’ decisions to prescribe an antibiotic. Are any of these physical findings good reason for prescribing an antibiotic? Other than rales, which may be associated with pneumonia, there is no good empiric evidence that purulent nasal discharge, postnasal discharge, rhonchi, or sinus tenderness distinguish between viral and bacterial illnesses.12 Purulent nasal discharge is commonly thought to indicate bacterial infection, but this is not supported by clinical or laboratory research.6 Purulent nasal discharge does increase the odds of sinusitis, but it is unclear whether uncomplicated sinusitis diagnosed on clinical grounds improves more rapidly with antibiotic treatment.17-20 The Centers for Disease Control and Prevention guidelines for treatment of sinusitis in children recommend no antibiotic unless symptoms are severe or have been present for more than 10 days.21
Inadequate Physician Knowledge
It has been suggested that inadequate knowledge of the nature of viral illnesses accounts for inappropriate antibiotic prescribing practices.5 Our findings support this assertion. The high percentage of cases of sinusitis (37%) and relatively low percentage of antibiotic prescriptions for nonspecific URI (21%) suggest that clinicians may have assigned the diagnoses of sinusitis to justify an antibiotic prescription, as has been suggested by Vinson and Lutz16 for bronchitis. However, this would suggest that clinicians intentionally falsified physical findings to justify antibiotic prescribing to satisfy patient demand or for other unidentified reasons. It is more likely that sinus tenderness was the basis for a diagnosis of sinusitis, rales or rhonchi were the basis for a diagnosis of bronchitis, and these diagnoses were the justification for prescribing an antibiotic.
Before an all-out war on antibiotics is waged, however, a very large randomized controlled trial of antibiotic treatment of acute respiratory infections that would allow subgroup analysis by the factors we have described may be necessary to determine whether some cases of ARI are antibiotic responsive. Although current evidence does not strongly support use of antibiotics for URIs, acute bronchitis, or acute sinusitis, sufficient evidence does not exist to refute a clinically significant effect in certain subgroups of these patients.
We found that the clinicians in our network depend on the presence of discolored nasal drainage, postnasal drainage, rales or rhonchi, sinus tenderness, and clear nasal drainage to decide whether to prescribe an antibiotic for patients with a URI, acute bronchitis, and acute sinusitis. In making their decisions they also considered the clinical course of the illness and a subjective assessment of the likelihood a patient will get worse without an antibiotic. We found that patients expect an antibiotic if they have had a similar illness in the past and had improved with an antibiotic; yet patient expectation alone does not appear to be a sufficient reason for clinicians to prescribe antibiotics for acute respiratory infections. These new findings may be of benefit to those designing interventions to reduce inappropriate use of antibiotics for acute respiratory infections.
Acknowledgments
We express our gratitude to Teresa L. Ettenhofer, Renee Lauscher, and Meghana Kasetty, MD, of Escanaba and the clinicians and office staffs of the following Upper Peninsula Research Network practices: Alcona Health Center in Lincoln, Alpena Medical Arts in Alpena, Burns Clinic in St. Ignace, Doctors Park Family Physicians in Escanaba, East Jordan Family Health Center in East Jordan, Ewen Medical Center in Ewen, OSF Medical Group in Escanaba and Gladstone, Gwinn Medical Center in Gwinn, Mackinac Straits Primary Care Clinic in St. Ignace, Marquette Internal Medicine Associates in Marquette, Marquette Medical Clinic in Iron River, and Northern Michigan Health Services in Houghton Lake.