In this study, we used a nationally representative data set regarding ambulatory visits to examine time trends in visit rates and antibiotic prescribing for children with acute sinusitis. Unlike the observed decrease in the visit rate for AOM during the post-PCV7 period,3
the visit rate for acute sinusitis among children did not change between 1998 and 2007. During the same period, and in accordance with the publication of AAP clinical practice guidelines for acute sinusitis in 2001, use of amoxicillin for acute sinusitis increased substantially. This change was similar to the change in prescribing for AOM after the publication of guidelines in 2004.9
In addition, we found that pediatric specialty and younger patient age were associated with amoxicillin prescribing for acute sinusitis. Although the increased use of amoxicillin is consistent with recommendations from AAP guidelines, we also found that use of macrolides remained common for acute sinusitis.
Our findings with respect to visit rates for acute sinusitis may be explained by differences in how physicians diagnose acute sinusitis, compared with AOM. Whereas the diagnosis of AOM involves both clinical history findings and distinct physical examination findings,6
acute sinusitis is frequently diagnosed on the basis of the patient's history alone.5,6,15
Furthermore, physicians disagree regarding which symptoms define a clinical history suggesting acute sinusitis. In a recent survey of pediatricians, most respondents thought that prolonged symptoms represented an important sign of acute sinusitis, but they varied in their responses regarding the importance of specific symptoms (eg, purulent rhinorrhea) or symptom combinations in establishing a diagnosis.16
The absence of a reliable, specific, physical finding that defines acute sinusitis inevitably leads to misclassification of children with viral upper respiratory tract infections as having acute sinusitis. As a result, recent practice guidelines and campaigns for judicious management of respiratory infections (eg, the Centers for Disease Control and Prevention Get Smart Campaign17
) may be more effective in influencing physicians to diagnose AOM more stringently (eg, excluding otitis media with effusion) than is possible for acute sinusitis. Studies using administrative data found that, after introduction of PCV7, the visit rate for AOM decreased by an amount that exceeded the estimated efficacy of the vaccine, which suggests that changes in how physicians diagnose AOM may account for a substantial proportion of the observed decrease in AOM visits.7,8
Although there is mixed evidence regarding the effectiveness of antibiotics for treatment of acute sinusitis in children,18–20
physicians routinely prescribe antibiotics for treatment of acute sinusitis, and this practice has not changed in the past decade. The proportion of visits in which an antibiotic was prescribed for acute sinusitis in children alone is similar to the rate estimated for children and adults combined in a previous study.1
This is also similar to the proportion of visits that result in an antibiotic prescription for AOM,9
for which efforts to reduce antibiotic use through observation and delayed prescribing seem to have had limited success.9,21
To continue to promote judicious antibiotic prescribing for these infections, novel strategies to enhance the acceptability of such practices likely are needed.
Although prescribing of amoxicillin for acute sinusitis seemed to have begun to increase even before guideline publication in 2001, we found that it continued to increase substantially after the publication of AAP practice guidelines in 2001. A similar association between the timing of guideline publication and changes in antibiotic selection for AOM was noted in a recent publication that used the same administrative data set as analyzed in this study.9
The use of amoxicillin increased in the 2 years after publication of the AAP guidelines for AOM in 2004, reversing an earlier trend of increased use of broad-spectrum agents.10
Guidelines that are well disseminated, are consistent with physicians' beliefs,22
and provide epidemiologically sound rationale can be effective tools in influencing and/or reinforcing prescribing behavior, especially for infectious diseases.23
In separate multivariate models that included either patient age or physician specialty among independent variables, we found that younger patient age and pediatric specialty were independently associated with greater odds of amoxicillin use for acute sinusitis. Because colinearity precluded the simultaneous inclusion of these variables in a single model, we were unable to determine fully the extent to which either or both of these factors were associated with amoxicillin use. It is possible that younger children are more likely than older children to receive amoxicillin, independent of specialty, because of differences in the clinical presentation of acute sinusitis between age groups. Younger children may experience symptoms of acute sinusitis that are less specific or less severe than those experienced by older children, in part because of the existence of only partially developed frontal sinuses and a higher incidence of viral infections in this population.24–26
For these reasons, physicians may base the diagnosis and corresponding treatment of acute sinusitis in this patient population on different criteria than they would use for older children.16
Undeveloped frontal sinuses also make younger children less likely to develop intracranial complications,27
which perhaps encourages prescription of a narrow-spectrum agent such as amoxicillin for this group. Conversely, pediatricians might be more likely to prescribe amoxicillin because of a greater influence of AAP guidelines on their practices. Notably, however, a previous study found no difference between pediatricians and family practitioners in their antibiotic-prescribing patterns for AOM.10
Although we examined antibiotic-selection trends for acute sinusitis in the context of current guidelines recommending amoxicillin as the first-line agent, the appropriate empiric antibiotic agent remains somewhat uncertain. An increase in nontypeable Haemophilus influenzae
as a causative organism may make amoxicillin-clavulanate a more-appropriate empiric choice than amoxicillin in some communities.4
In addition, a recently published clinical trial showed that use of amoxicillin-clavulanate, compared with placebo, was effective in resolving symptoms for stringently diagnosed acute sinusitis in children.20
These epidemiological and clinical factors will need to be considered for future updates in clinical guidelines for acute sinusitis.
The frequent use of macrolides for treatment of acute sinusitis, as shown in this study, is potentially problematic because macrolide resistance among S pneumoniae
in the United States is common.28
Previous studies showed increased use of macrolides for children overall29
and for children with AOM.10
This study confirms that reducing unnecessary use of macrolides for pediatric upper respiratory tract infections is an important target for improvement in antibiotic prescribing.
We acknowledge limitations to this study. First, our relatively small sample size limited the power of certain statistical analyses. For example, we might not have been able to detect small trends in visit rates for acute sinusitis from this data set, either for children overall or for specific age groups, and our multivariate model may lack the power to detect additional factors associated with amoxicillin prescribing. In time-trend analyses, some periods have fewer than 30 observations, which may yield unstable results. However, when combined into two 5-year periods with larger sample sizes, the observed trends were nearly identical. In addition, variation exists in how physicians diagnose acute sinusitis.16
Because we used administrative data, we were not able to verify specific symptoms associated with our sampled visits and thus were unable to measure the degree to which these characteristics of our sample correlate with those outlined in published national guidelines.