a Department of Pediatrics, Boston University School of Medicine, Boston, Massachusetts
b Departments of Epidemiology and Statistics and Data Coordinating Center, Boston University School of Public Health, Boston, Massachusetts
| ABSTRACT |
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METHODS. A cluster randomization study was conducted in 12 pediatric practices (6 intervention and 6 control sites). The main outcome measures were adherence to the CDC recommendations (modified to include 2 additional antimicrobial agents) and a subsequent antibiotic prescription for AOM within 30 days after diagnosis.
RESULTS. Of 3152 patients referred to research assistants, 2584 (82%) were eligible. Of those eligible, 1368 (99%) of 1382 at the intervention sites and 1138 (99%) of 1146 at the control sites consented to participate. Rates of adherence to the CDC recommendations were not significantly higher at the intervention sites than at the control sites, for initial enrollment episodes (78.2% vs 70.6%) or second episodes (62.6% vs 59.9%). After controlling for clustering according to site and covariates, children who were not treated in adherence to the CDC recommendations for both episodes had 1.60 times the odds of a subsequent prescription within 12 days, compared with those treated in adherence at both episodes.
CONCLUSIONS. Despite using evidence-based approaches that are known to influence physician behavior, we were unable to increase adherence to the CDC recommendations for treatment of AOM. However, we did establish that prescription of antimicrobial therapy consistent with the CDC recommendations for a second episode of AOM was associated with improved outcomes, measured as the need for subsequent antibiotic prescription. Because of the selection of resistant otopathogens, adherence to the CDC recommendations is likely more important in subsequent episodes of AOM than in the initial episode.
Key Words: acute otitis media treatment Centers for Disease Control and Prevention recommendations
Abbreviations: AOMacute otitis media CDCCenters for Disease Control and Prevention
An increase in antimicrobial agent resistance among otopathogens has made the treatment of acute otitis media (AOM) more challenging.1,2 Throughout the 1990s, Streptococcus pneumoniae became increasingly resistant to multiple antibiotics, including amoxicillin, cephalosporins, macrolides, clindamycin, and trimethoprim/sulfamethoxazole.3,4 Because practitioners rarely culture specimens from the middle ear and thus have no knowledge of antimicrobial agent-resistant pathogens for individual patients, the presence of risk factors for a resistant middle ear pathogen, including young age, day care attendance, and previous antibiotic exposure, should be incorporated into selection of an antimicrobial agent for the treatment of AOM.57 Certain antibiotics are more likely to result in improved clinical outcomes because they are more effective in the eradication of middle ear pathogens, on the basis of direct evidence from human bacteriologic efficacy trials or, when such evidence is lacking, pharmacokinetic and pharmacodynamic properties of the antibiotic.8,9
In 1999, the Centers for Disease Control and Prevention (CDC) released recommendations for the use of specific antimicrobial agents for the treatment of AOM.9 These recommendations were reached through consensus and were based on data available at the time. In general, these recommendations advocated use of amoxicillin as first-line therapy for children at low risk for resistant otopathogens and high-dose amoxicillin, high-dose amoxicillin/clavulanate, or cefuroxime for children at higher risk. Antibiotic use in the previous 30 days was the principal risk factor for antibiotic-resistant pathogens in the CDC recommendations. Day care attendance was cited as a risk factor but was not incorporated into the decision scheme.
The purpose of this study was to determine whether we could increase adherence to the CDC recommendations by using well-accepted approaches known to improve physician behavior and whether adherence to the CDC recommendations resulted in improved outcomes for AOM. Because the microbiologic features of recurrent AOM may be altered after treatment of an initial episode,10,11 we hypothesized that adherence to the CDC recommendations for treatment of a second episode of AOM would result in reduced rates of treatment failure, measured as the need for subsequent antibiotic treatment within 12 days after diagnosis of a recurrent episode.
| METHODS |
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Enrollment and Follow-Up Monitoring
When a patient was diagnosed as having AOM and a provider thought that the patient was potentially eligible, the subject was referred to a research assistant. Research assistants were assigned to each practice for 35 hours per week. The research assistants reviewed the eligibility criteria and enrolled appropriate subjects. At that time, in addition to sociodemographic information, the research assistant gave the family a daily symptom diary to complete and arranged to contact the family 3 to 5 days and 9 to 11 days later. The family was instructed to complete the diary until the child was free of symptoms and to return it by mail. The research assistant contacted the family twice during the subsequent 2 weeks and obtained additional data about the child's well-being. This interview focused on resolution of symptoms and prescriptions for additional antibiotics. If a subject was diagnosed as having recurrent AOM, then the clinicians were to refer the patient back to the research assistant, so that a new diary could be initiated. Patients were again called 3 to 5 days and 9 to 11 days later.
Patients were monitored for 60 days; the research assistants reviewed the medical records of each patient for 60 days after enrollment, to determine whether the child received any subsequent antibiotic treatment. The chart review was performed to ensure that we had complete follow-up data for all enrolled patients.
Statistical Analyses
Intervention and control practices were compared with respect to patient demographic features with
2 tests. To account for our cluster-sample design, study groups were compared with respect to outcomes with generalized estimating equation logistic regression models, which account for clustering of patients within practices in estimations of both effects and SEs. Patient characteristics that were found to differ between study groups were controlled for as covariates in these analyses. For our first goal, we compared study groups with respect to treatment adherence to the CDC recommendations, for both the enrollment episode of AOM and second episodes of AOM during the 60-day study period. For our second goal, we compared those treated in adherence versus not in adherence to the CDC recommendations with respect to the need for a second antibiotic prescription for an episode of AOM. For enrollment episodes, we analyzed prescriptions by both day 12 and day 17. For second episodes, we categorized patients according to adherence to CDC guidelines during both the enrollment episode and the second episode and compared those treated in adherence to the guidelines during both episodes with those treated in other combinations. These analyses were also through generalized estimating equation logistic regression, controlling for patient characteristics found to differ between study groups. We also described the time to a second antibiotic prescription for second treatment episodes with Kaplan-Meier survival curves, although this analysis does not control for clustering according to practice.
The study was approved by the institutional review board of Boston University Medical Center. Oral consent was obtained from all participants.
| RESULTS |
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A majority of the children enrolled were male, were white, and had private insurance (Table 3). The mean age was 1.41 years for the intervention sites and 1.37 years for the control sites. Approximately one half of the children were in day care. The majority of primary caregivers were the mothers, were married, and had more than a high school education (Table 3). The following variables differed significantly between the control and intervention sites: race, Hispanic origin, child feeding history, number of smokers in the household, insurance status, race of primary caregiver, age of primary caregiver, marital status, educational status of primary caregiver, and family income. We controlled for these differences in our analyses.
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| DISCUSSION |
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We did establish that prescription of antimicrobial therapy consistent with the modified CDC recommendations for a second episode was associated with improved outcomes, measured as the need for a subsequent antibiotic prescription. This finding, although expected from a microbiologic and pharmacologic perspective, is unusual from a methodologic standpoint. It is difficult to demonstrate the effects of antibiotic therapy in AOM by using clinical end points.16 AOM is a complex disease, often of combined bacterial and viral etiology. Improvement and persistence of symptoms do not have clear relationships with the ability of an antibiotic to eliminate pathogens from the middle ear.17,18 In addition, treatment for AOM needs to be understood in the context of local patterns of antibiotic resistance. A report from Massachusetts indicated that, in the post-heptavalent pneumococcal conjugate vaccine era, 33% of 190 nasopharyngeal isolates were not susceptible to penicillin.19 In our trial in a real-world practice setting, we used a repeat antibiotic prescription as a surrogate measure of a poor clinical outcome, and we made no attempt, except for academic detailing, to ensure an accurate diagnosis of AOM. These factors conspire against demonstrating an effect of less-optimal antibiotic therapy, but we demonstrated an effect by performing a large trial with >900 second episodes of AOM. There has been only 1 previous clinical trial of AOM with a sample size of similar magnitude.20
Adherence to the CDC recommendations for a recurrent episode of AOM reduces the need for subsequent antibiotics.21 Consistent with the hypothesis of the CDC working group that formulated the recommendations, we hypothesized that recurrences that occurred within 30 days after the enrollment episode would be more likely attributable to resistant otopathogens. Dagan et al21 demonstrated that such recurrent episodes are likely attributable to otopathogens that remain in the nasopharynx during treatment for the initial episode or are newly acquired shortly thereafter and have an increased likelihood of antimicrobial agent resistance. Consistent with our hypothesis, we found that using certain antibiotics, particularly after a second episode, reduced significantly the need for a third antibiotic within either a 12-day or 17-day window. Following the CDC recommendations for both the initial and subsequent episodes resulted in a 34% reduction in the need for an additional antibiotic. We evaluated outcomes at both 12 and 17 days after initiation of antimicrobial therapy. Twelve days has been a traditional time for assessing outcomes in clinical trials of AOM. We used a 17-day (10 days of traditional therapy and 7 additional days) outcome because Leibovitz et al22 demonstrated that recurrent episodes within 7 days after completion of antimicrobial therapy were more likely to be attributable to relapse (the same pathogen) than were recurrences after 7 days. We acknowledge that there is uncertainty about the appropriate time point to use for defining outcomes; therefore, we also presented the data as a survival plot. The difference remains significant for the 30-day period after a second AOM episode.
Our inability to increase adherence to the CDC recommendations is surprising. We used a multifaceted approach that included reverse academic detailing with local opinion leaders, 2 of the authors visited the practices twice during the study, the intervention practices were given feedback about how their sites were performing with respect to the choice of specific antibiotics (although, admittedly, this did not include either site-specific or physician-specific information), and, finally, reminders were placed on the charts of every eligible patient and included in the newsletter. There are numerous potential explanations for our failure to have an impact on practices. First, it remains difficult to change physician behavior. This may be particularly true for specific antibiotics for treatment of AOM in the ambulatory care setting, because physicians may think that most of the available antibiotics are efficacious in AOM and may not recognize that some of the available antibiotics are not efficacious for some otopathogens. Second, we might have underestimated the extent to which parents influence the choice of specific antibiotics, as a result of their prior personal experience. Our study population was drawn largely from a population of middle or high socioeconomic status, and it is possible that parents in this group exert greater influence on physicians than do other parents. Interestingly, children of higher socioeconomic status are at greater risk for resistant S pneumoniae. Third, rates of adherence to the CDC recommendations were relatively high for the control practices, ie, 70% for the initial episode and 60% for the second episode. This made it more difficult to find a difference between the intervention and control sites. However, a doubling of the use of azithromycin and cefprozil for high-risk episodes is inconsistent with available evidence, because both are likely to be most effective when the risk for multidrug-resistant S pneumoniae or H influenzae is low. Multidrug-resistant S pneumoniae and H influenzae have been found to be increased in recurrent episodes.23
The challenge of conducting AOM research in clinical practices involves the validity of the diagnosis and an understanding of how patterns of antibiotic resistance affect the choice of antimicrobial agent. We did not use any objective test, such as tympanometry, that might have assisted practitioners in making more-accurate diagnoses of AOM; instead, we relied on their skills. This is a limitation of the study. However, the project was designed specifically to address the effectiveness of the CDC recommendations in the office practice setting, rather than in the context of carefully controlled clinical trials. Even with optimal diagnostic conditions, 20% of patients do not have bacterial infection of the middle ear. Under the diagnostic conditions of routine clinical care, many patients have otitis media with effusion rather than AOM or may not even have middle ear fluid and infection. Diagnostic error rates for AOM in clinical practice are not known but are thought to be substantial.24 However, the failure to make a proper diagnosis of AOM would only dilute any potential to observe differences (presuming that such failure is equivalent to physicians not following the recommendations) and would not increase artificially the benefit of prescribing medications in accordance with the recommendations. Therefore, for children with true bacterial AOM, the benefits of treatment in accordance with the recommendations are likely to be even greater than we observed.
This study demonstrates that, for episodes of AOM at high risk for resistant pathogens, the selection of certain antimicrobial agents results in improved outcomes, measured as the need for subsequent antibiotics for treatment of AOM within 30 days. We are unaware of other practice-based data that support the importance of adherence to the CDC AOM recommendations.
| ACKNOWLEDGMENTS |
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The Boston-Based Pediatric Research Group includes Concord Hillside Medical Associates (Concord, MA), Framingham Pediatrics (Framingham, MA), Holliston Pediatric Group (Milford, MA), Hyde Park Pediatrics (Hyde Park, MA), Lahey Clinic-Pediatric and Adolescent Practice (Burlington, MA), Lexington Pediatrics (Lexington, MA), Main Street Pediatrics (Hopkinton, MA), Milford Holliston Pediatric Group (Milford, MA), Newton Center Pediatrics (Newton, MA), Patriot Pediatrics (Bedford, MA), Pediatric Associates of Medford (Medford, MA), and Pediatric Association of Northwoods (Taunton, MA).
We thank Paul Little, Eugene Shapiro, and Bruce Fireman, who were on our scientific oversight committee. They provided insight into the design and execution of the study and reviewed the manuscript before submission.
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Address correspondence to Howard Bauchner, MD, Boston Medical Center, 91 East Concord St, Boston, MA 02118. E-mail: howard.bauchner{at}bmc.org
Financial Disclosure: Dr Marchant is a consultant and serves on the speaker bureaus for Glaxo-Smith-Kline and Abbott; Dr Pelton serves on advisory boards for Glaxo-Smith-Kline and Sanofi Pasteur.
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