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* Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee
Departments of Pediatrics
Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
|| Methodist Health Care, Memphis, Tennessee
| ABSTRACT |
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Methods. This cross-sectional study involved patient encounters in outpatient departments that were included in the US National Hospital Ambulatory Medical Care Survey database from 1995 to 2000. Encounters with patients who were aged <18 years and had a primary diagnosis suggestive of viral respiratory tract infection were evaluated. Patients with comorbid conditions that might justify antibiotic use were excluded.
Results. This study included 1952 patient encounters with a primary diagnosis suggestive of a viral infection and 33.2% of these patients receiving antibiotics. Overall, antibiotic use was significantly less among HS (19.5%) than staff physicians (36.4%; odds ratio [OR]: 0.44; 95% confidence interval [CI]: 0.330.59). This difference between HS (19.5%) and staff physicians (32.5%) persisted even within teaching hospitals (OR: 0.5; 95% CI: 0.4-0.7). Among staff physicians, antibiotic use was greater among those who work in nonteaching (39.6%) compared with teaching hospitals (32.5%; OR: 1.51; 95%: CI 1.15-1.98). Controlling for other patient and provider variables, antibiotic use occurred less among HS than among staff physicians in teaching hospitals (OR: 0.53; 95% CI: 0.38-0.75).
Conclusions. Antibiotic prescribing in the context of an outpatient visit for a diagnosis suggestive of a viral respiratory tract illness occurs more commonly among staff physicians than trainees and among staff physicians more commonly in nonteaching compared with teaching institutions.
Key Words: antibiotic use physician practice patterns children viral infections
Abbreviations: URTI, upper respiratory tract infection HS, housestaff NHAMCS, National Hospital Ambulatory Medical Care Survey ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification CDC, Centers for Disease Control and Prevention AAP, American Academy of Pediatrics OR, odds ratio
Antibiotic resistance has become a global problem, with resistance among Streptococcus pneumoniae, among others, a major focus of concern.1,2 The association of antibiotic use and overuse with development of resistance36 and reversal of resistance patterns with decreased use has been previously demonstrated.710 Respiratory tract infections including otitis media are clearly the leading indication for outpatient antibiotic prescriptions.11 Numerous studies have shown that a substantial number of prescriptions for antibiotics are provided in cases in which antibiotic use has unproven benefit,12 such as for upper respiratory tract infections (URTIs), the common cold, bronchitis, and bronchiolitis.1316
Although much has been written on patient characteristics and provider variables such as physician specialty and practice location, few have examined the influence of training status and teaching environment on antibiotic overuse.14,1720 This study was done to evaluate the differences in potential overuse of antibiotics in hospital-based outpatient clinics among residents (housestaff [HS]) and staff physicians as well as among staff physicians who work in teaching versus nonteaching hospitals.
| METHODS |
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Inclusion criteria for this study were outpatient visits for patients who were <18 years of age and for whom the primary diagnosis was 1 of 4 common viral diagnoses: acute nasopharyngitis (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 460); acute URTI of multiple or unspecified sites (ICD-9-CM code 465); acute bronchitis and bronchiolitis (ICD-9-CM code 466); or bronchitis, not otherwise specified (ICD-9-CM code 490). Only visits by patients who were seen by a staff physician (autonomous visit not seen in conjunction with a resident/intern/nurse practitioners or physician assistants) or resident/intern were analyzed. We excluded visits in which a secondary diagnosis could have justified antibiotic use, such as streptococcal sore throat and scarlet fever (ICD-9-CM code 034), suppurative and unspecified otitis media (ICD-9-CM code 382), mastoiditis and related conditions (ICD-9-CM code 383), acute sinusitis (ICD-9-CM code 461), acute pharyngitis (ICD-9-CM code 462), acute tonsillitis (ICD-9-CM code 463), chronic sinusitis (ICD-9-CM code 473), pneumococcal or other bacterial pneumonia (ICD-9-CM code 481 and 482), chronic bronchitis (ICD-9-CM code 491), cystitis (ICD-9-CM code 595), and skin infections (ICD-9-CM codes 680-684, 686). In addition, we excluded visits in which a comorbidity such as asthma (ICD-9-CM code 493), cystic fibrosis (ICD-9-CM code 277), chronic airway obstruction (ICD-9-CM code 496), chronic cardiopulmonary disease (ICD-9-CM code 416.9), symptomatic HIV (ICD-9-CM code 042), or organ or tissue replaced by transplant (ICD-9-CM code V42) could have prompted an antibiotic prescription.
Antibiotic Use
Oral or parenteral antibiotic use in a clinical setting suggestive of a viral respiratory tract infection as mentioned above was noted. Antibiotics were identified by searching for the National Drug Code Directory Drug Classes codes for penicillins, cephalosporins, macrolides, sulfonamides and trimethoprim, quinolones, tetracyclines, and other miscellaneous antibacterial agents.
Training Status and Hospital Type
We designated hospitals as "teaching" when any visit in the NHAMCS database from that hospital was to a trainee (intern or resident [HS]), whereas hospitals in which there were no patient visits to HS were designated "nonteaching." This assignment as teaching or nonteaching was done before applying any inclusion or exclusion criteria by using data from all visits in the NHAMCS database from 1995 to 2000.
Analytic Strategy
All analysis was done on unweighted data. The primary endpoint of the study was the prescription of an oral antibiotic for an eligible visit, and our primary exposures were trainee status and hospital teaching status, as defined above. Potential covariates included patient demographics and insurance information, hospital location, and clinic type. Temporal variables included year as well as whether the visit occurred after the publication of the guidelines on appropriate use of antibiotics in children in 1998 by the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP).24 Unadjusted odds ratios (ORs) and adjusted ORs were calculated using logistic regression analysis. To prevent the possibility that the prescribing practices in a hospital that contributed multiple patients to our study population could unduly influence our results, we adjusted all analysis for "clustering" of nonindependent observations within hospital.25 Because the NHAMCS provides a unique identification of individual hospitals, we used general estimating equations to account for nonindependence of observations within the same hospital. To explore further differences between antibiotic prescribing among staff physicians and HS, we conducted stratified analyses by selected characteristics. Data analysis was done using the statistical software SAS, version 8.1 (SAS, Cary, NC).
| RESULTS |
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Of the 1952 patients with a diagnosis suggestive of a viral infection, 648 (33.2%) had antibiotics prescribed. Penicillins (includes aminopenicillins), macrolides, and cephalosporins constituted 57%, 24%, and 12% of all oral antibiotic prescriptions, respectively. On the basis of the primary diagnosis, antibiotic use was seen most in patients who had a diagnosis of bronchitis, not otherwise specified (69.5%), followed by acute bronchitis and bronchiolitis (47.8%), acute nasopharyngitis (39.7%), and acute URTI of multiple or unspecified sites (25.7%). Given the disproportionately higher antibiotic use for patients who had a diagnosis of bronchitis, not otherwise specified, for the purpose of further analysis, we elected to compare this category with the other 3 diagnostic categories.
Antibiotic use in children and adolescents with a diagnosis suggestive of a viral respiratory tract infection was significantly less among HS (19.5%) than staff physicians (36.4%; OR: 0.44; 95% confidence interval [CI]: 0.330.59; P < .0001). This difference between HS (19.5%) and staff physicians (32.5%) persisted even within teaching hospitals (OR: 0.5; 95% CI: 0.40.7; P < .0001; Fig 1). Among staff physicians, antibiotic use was greater among those who worked in nonteaching (39.6%) compared with teaching hospitals (32.5%; OR: 1.51; 95% CI: 1.151.98; P = .003).
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The odds of antibiotic use when seen by HS when compared with any staff physician (teaching or nonteaching) was also examined within each strata of the other variables associated with antibiotic use while including the remaining covariates in the model (Fig 3). Overall, the difference in antibiotic use between the 2 training cohorts remained significant and generally consistent within all strata (including before and after publication of CDC/AAP guidelines) except for being seen in a nonmetropolitan statistical area or being seen in the West.
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| DISCUSSION |
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There are several possible explanations for the lower use of antibiotics among trainees compared with staff physicians. First, although the reasons for a visit are similar, patients who see staff physicians might be sicker than those who are seen by trainees. However, the distribution of symptoms, specifically fever, as the major reason for visit was similar among all groups of physicians. Second, although we controlled for insurance status, there may be differing expectations among parents with staff physicians compared with trainees. Third, one can speculate that trainees may feel sheltered in an academic environment and perceive less medicolegal risk when withholding antibiotics in specific clinical situations compared with practicing clinicians in hospital-based outpatient departments. Finally, our findings may represent a "cohort effect"; trainees may be more familiar with recently administered guidelines and may be more comfortable with antibiotic restraint than providers who trained and practiced before the dissemination of these guidelines. We have observed a similar cohort effect in the choice of hypnotic agents for older adults between interns and attending physicians.26
Our findings are similar to those of Mincey et al,19 who noted that within a teaching facility, contrary to their expectations, junior residents were more likely to prescribe an appropriate antibiotic for sinusitis than senior residents and staff physicians and that with increasing level of training, residents' prescribing practices more closely resembled those of the supervising physicians. A study of antibiotic prescribing practices for patients with colds, URTIs, and bronchitis using emergency department records in the 1996 NHAMCS database found a similar difference in antibiotic use between HS and staff physicians as seen in the current study.14 Mainous et al,18 using information from the Kentucky Medicaid database, reported that the "high prescribers" of antibiotics for children with URTIs were significantly more years from medical school graduation (27 vs 19 years) than "low prescribers."
The use of antibiotics was higher among staff physicians who practice in nonteaching compared with teaching institutions. A number of studies have compared the differences in quality of care between teaching and nonteaching hospitals, with some of the more rigorous studies indicating better care in major teaching hospitals for conditions such as myocardial infarction.27 In a study reported by Steinke et al,20 nontraining practices in Tayside, UK, were in general found to prescribe significantly more antibiotics as well as a higher proportion of broad-spectrum penicillins, a higher proportion of newer antibiotics, and a greater number of different antibiotics per doctor compared with training practices.
In addition, there may be differential access to recent literature among trainees (HS) who function in an academic environment versus staff physicians who are not engaged in formal teaching and may have variable access and commitment to continuing medical education. This may be one of the explanations for the much wider difference in antibiotic use among nonteaching staff physicians and HS. It was shown previously that a physician's performance on certification examinations deteriorates over time.28 Also, Tamblyn et al29 showed that scores achieved on certification and licensure examinations that are taken at the end of medical school in Quebec show a sustained relationship over 4 to 7 years with indices of preventive care and acute and chronic disease management in primary care practice. Furthermore, over the past decade, numerous national organizations have actively campaigned toward reducing antibiotic overuse, and the greatest impact of the message may have been on the most impressionable part of the clinical workforce, namely the HS.24,30 A number of factors have been identified as barriers that physicians face in adhering to clinical practice guidelines.31
As has been reported by others,21,22,32 the encouraging overall trend in decreased antimicrobial use in the outpatient setting was also seen in this study. Despite using the CDC/AAP guidelines regarding appropriate use of antibiotics in pediatric URTIs as the time point around which secular trends in antibiotic prescribing were examined in this study, we acknowledge that these guidelines are one among many measures taken over the past decade to decrease antibiotic overuse.33 Hence, the causal relationship between publication of these guidelines and decreased antibiotic use, although implied, is not exclusive. Nambiar et al17 reported the results of a survey that assesses awareness and compliance of pediatric residents with the CDC and AAP guidelines regarding "principles of judicious use of antibiotics in URI." On the basis of responses to the survey questionnaire, including clinical vignettes, they found a trend toward improving awareness of the guidelines and decreased antibiotic use with increasing years of training.
Several limitations of this study warrant additional discussion. First, it should be noted that because many of the HS visits may have been partially or completely supervised by staff physicians, the antibiotic prescribing behavior of the HS seen in this study reflects in part the prescribing style of the supervisors. Despite accounting for the teaching status of the hospital where the clinic was located, we cannot totally rule out the contribution of direct or indirect supervision in the prescribing style of the HS. Second, with the NHAMCS database, we cannot confirm the accuracy of the diagnosis reported by the participating providers to identify visits for presumed viral respiratory tract infection. However, similar to previous investigators who have used encounter data in the National Ambulatory Medical Care Survey database to evaluate inappropriate antibiotic use,12,13 we restricted our study to include ICD-9 codes (listed for the primary diagnosis) for conditions for which antibiotic use is not recommended.24 Furthermore, we excluded visits for related chronic conditions (eg, chronic bronchitis) because appropriate use of antibiotics in these cases has not been established. That said, in the absence of medical history, we cannot account for differences in decision making influenced by the medical history of a patient such as a child with multiple previous episodes of otitis media or the premature infant with multiple postnatal problems. We also cannot be sure how many excluded visits for conditions for which antibiotic use is considered acceptable (eg, otitis media, sinusitis) were cases of overdiagnosis or miscoding to "justify" the antibiotic prescription.34 Aside from the possibility that such a practice was far more prevalent among trainees than staff physicians, such coding practices would underestimate rather than overestimate the antibiotic use and difference in antibiotic use observed in this study. One way, albeit not perfect, of addressing this possibility is to examine among the different clinical providers the proportion of clinic visits of patients who were <18 years of age and for whom a diagnosis of otitis media or sinusitis was made. This was seen in 8%, 5.2%, and 4.3% of overall pediatric visits to staff physicians (nonteaching), staff physicians (teaching), and HS, respectively, and if anything was less among HS than staff physicians. Third, it is also possible that despite the stringent exclusion criteria, some comorbid conditions that justify use of an antibiotic were missed. Fourth, differences in antibiotic prescribing may have been related to differences in severity of illness. Although we could not assess the same, we did look for differences in presenting symptoms, such as fever, in the visits to the 3 groups of providers and found no difference. Finally, we used the record of any HS visit from a hospital in the entire NHAMCS database as a surrogate measure to assign teaching status to that hospital. Although this definitely helped in teasing out the role of the teaching environment, it is an indirect measure with the potential of having a less-than-ideal sensitivity, ie, there may have been HS in the hospital but they did not contribute to the sample used for NHAMCS survey resulting in that hospital being designated "nonteaching."
In conclusion, this study suggests that prescribing practices of trainees during patient visits suggestive of a viral respiratory tract infection are more consistent with the existing antibiotic prescribing guidelines than those of staff physicians in hospital-based outpatient departments. Although we are hopeful that this cohort of trainees will continue this prescribing behavior once they enter practice, it is also conceivable that practice patterns will deteriorate as they exit the teaching environment. This study provides additional evidence that additional, focused measures to educate and remind the staff physicians in hospital-based outpatient clinics, including continuing medical education,3537 educational outreach intervention,38 and point-of-care interventions,39 would further complement the gains made in decreased antibiotic use over the past decade.
| ACKNOWLEDGMENTS |
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We thank Grant W. Somes, PhD, Department of Preventive Medicine, University of Tennessee Health Science Center (Memphis, TN), for assisting in the analysis and interpretation of data in this study.
| FOOTNOTES |
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Reprint requests to (A.H.G.) Department of Infectious Diseases, St Jude Children's Research Hospital, 332 N Lauderdale St, Memphis, TN 38105-2794. E-mail: aditya.gaur{at}stjude.org
No conflict of interest declared.
| REFERENCES |
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This article has been cited by other articles:
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B. Robbins and J. D. Dickerman Practice May Not Make Perfect AAP Grand Rounds, May 1, 2005; 13(5): 52 - 53. [Full Text] [PDF] |
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