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OBJECTIVE: One of the major factors influencing length of stay for patients with community-acquired pneumonia is the timing of conversion from intravenous to oral antibiotics. We measured physician attitudes and beliefs about the antibiotic switch decision and assessed physician characteristics associated with practice beliefs.
DESIGN: Written survey assessing attitudes about the antibiotic conversion decision.
SETTING: Seven teaching and non-teaching hospitals in Pittsburgh, Pa.
PARTICIPANTS: Three hundred forty-five generalist and specialist attending physicians who manage pneumonia in 7 hospitals.
MEASUREMENTS AND RESULTS: Factors rated as “very important” to the antibiotic conversion decision were: absence of suppurative infection (93%), ability to maintain oral intake (79%), respiratory rate at baseline (64%), no positive blood cultures (63%), normal temperature (62%), oxygenation at baseline (55%), and mental status at baseline (50%). The median thresholds at which physicians believed a typical patient could be converted to oral therapy were: temperature ≤100°F (37.8°C), respiratory rate ≤20 breaths/minute, heart rate ≤100 beats/minute, systolic blood pressure ≥100 mm Hg, and room air oxygen saturation ≥90%. Fifty-eight percent of physicians felt that “patients should be afebrile for 24 hours before conversion to oral antibiotics,” and 19% said, “patients should receive a standard duration of intravenous antibiotics.” In univariate analyses, pulmonary and infectious diseases physicians were the most predisposed towards early conversion to oral antibiotics, and other medical specialists were the least predisposed, with generalists being intermediate (P < .019). In multivariate analyses, practice beliefs were associated with age, inpatient care activities, attitudes about guidelines, and agreeableness on a personality inventory scale.
CONCLUSIONS: Physicians believed that patients could be switched to oral antibiotics once vital signs and mental status had stabilized and oral intake was possible. However, there was considerable variation in several antibiotic practice beliefs. Guidelines and pathways to streamline antibiotic therapy should include educational strategies to address some of these differences in attitudes.
Each year in the United States, there are 1.2 million hospitalizations for community-acquired pneumonia at an estimated cost of 9 billion dollars.1,2 Previous studies have found wide variations in hospital length of stay in pneumonia3,4 that are not explained by differences in patient case mix or disease severity.5,6 These data suggest that variation in physician practices or hospital policies may be important determinants of length of stay.
One of the major management decisions influencing length of stay in pneumonia is the timing of conversion from intravenous to oral antibiotics. While most patients are usually discharged 1 day after switching to oral therapy, there is considerable variability in the overall duration of parenteral therapy.7 In a 4-hospital cohort study, we found that patients received a median of 6 days of intravenous antibiotics, even though the median time to clinical stability was three days.7 When surveyed about their management practices, 15% of the treating physicians reported that patients remained in the hospital, despite being clinically stable, to complete a “standard” duration of intravenous antibiotics.8
In response to these apparent inefficiencies in care, many practice guidelines and clinical pathways for patients hospitalized with community-acquired pneumonia recommend early conversion to oral antibiotics once patients are clinically stable as a way to decrease length of stay without compromising outcomes.9–11 Streamlining antibiotic therapy may also have important quality-of-care benefits by minimizing the risk of line infection and sepsis, decreasing patient deconditioning, and expediting recovery at home.
However, the success of efforts to promote the timely switch to oral antibiotic therapy may depend on the extent to which they are consonant with physicians' underlying attitudes and beliefs. Therefore, we administered a written survey on pneumonia management practices to help understand how physicians decide when patients should be switched to oral therapy. Our study has 2 goals: 1) to examine physician attitudes and beliefs about the antibiotic conversion decision, and 2) to assess physician characteristics underlying variation in attitudes about antibiotic conversion. We were particularly interested in whether physician age, specialty training, or other physician characteristics were associated with beliefs about treatment.
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The decision about when to convert a patient from intravenous to oral antibiotics is central to the inpatient management of community-acquired pneumonia as well as many other serious infectious diseases. Once patients are converted to oral antibiotics, they are usually discharged within a day or so (in the absence of other active problems), so the timing of conversion is a major determinant of length of stay and total cost of care. This study explored the factors that physicians consider important in determining readiness for antibiotic conversion and assessed the variations in underlying beliefs that may explain differences observed in clinical practice. Insight into these factors could be used to design medical practice guidelines and refine their corresponding implementation strategies.
The diverse group of physicians we studied identified absence of suppurative infection and bacteremia, ability to maintain oral intake, and normalized respiratory rate, temperature, oxygenation, and mental status as the most important clinical factors determining readiness for antibiotic conversion. Abnormalities in vital signs, ability to maintain oral intake, and mental status have been shown in previous work to be key criteria for judging overall clinical stability in pneumonia and are associated with the risk of clinical deterioration and short-term mortality.7,8,16,17 A small but significant proportion of physicians also emphasized normalization of the white count and resolution of the chest x-ray infiltrate, 2 traditional teachings that lack supportive evidence. Normalization of the white count, while a sensible physiological marker of infection, has never been independently associated with important pneumonia outcomes, and radiographic infiltrates can take weeks to months to resolve.18,19
There was general consensus about what constituted stable vital signs for the purposes of conversion to oral antibiotics except in the case of temperature. While 58% of physicians agreed that patients should be afebrile for 24 hours prior to the switch to oral therapy, there was broad difference of opinion about the exact definition of stable temperature, with just as many physicians saying this was ≤99°F (37.2°C) as ≤101°F (38.3°C). Because of this considerable variation in what physicians seem to regard as “afebrile” or “stable” temperature, local and national pneumonia guidelines and pathways should include explicit definitions of such terms so that recommendations can be operationalized in real world practice.
Fortunately, there is evidence to support specific recommendations. Several studies indicate that once a patient's temperature is 100°F (37.8°C) or less for 24 hours (and he or she is otherwise stable), he or she can be switched to oral therapy because the subsequent risk of clinical deterioration is very low.7,20 In addition, there are no differences in outcomes between patients who are discharged shortly after being switched to oral antibiotics compared to those who were observed for 24 hours or longer.21,22
Our survey identified other barriers to streamlining inpatient antibiotic therapy. One in 5 physicians felt that patients should receive a standard duration of intravenous therapy. This traditional practice is unnecessary in most cases for 2 reasons. First, several trials have shown that short courses of intravenous therapy in pneumonia are safe and effective.23–25 Second, the improved bioavailability of many new antibiotics allows oral preparations to rapidly achieve adequate serum levels (in patients with a functioning gastrointestinal tract). Once patients are stable according to objective criteria, they can be safely converted to oral antibiotics regardless of the number of days of intravenous therapy already received.
The modest differences we observed in practice style among medical specialty groups were intriguing. The overall trend was that pulmonologists and infectious diseases specialists were the most predisposed to early antibiotic conversion, generalists were intermediate, and other medical specialists the least predisposed to early switch. However, pulmonary and infectious diseases specialists and generalists seemed to think alike in pairwise comparisons. The fact that other medical specialists were the least predisposed towards early antibiotic conversion may reflect their relative lack of familiarity with the current pneumonia literature or national practice guidelines compared to their pulmonary/infectious diseases or generalist colleagues.26 These differences do not appear to be related to pneumonia experience per se, because annual pneumonia caseload was not a predictor of practice beliefs.
However, our multivariate analyses revealed that other physician characteristics were the important independent determinants of pneumonia practice attitudes, not specialty training. Not surprisingly, older physicians and those with more years in practice tended to hold more traditional practice beliefs, a finding reported previously.27 We were surprised that physicians with greater inpatient activities were less predisposed to early antibiotic conversion, though these clinicians may treat more severely ill patients.
The strengths of our study are that we surveyed attending physicians across a broad spectrum of medical specialties in a diverse group of hospitals. In addition, all study participants actually care for patients with pneumonia so our findings should reflect the attitudes and beliefs of real world clinicians. However, as with all physician survey research, we measured self-reported attitudes and practices, not actual behavior. In our survey, physicians were asked to consider the “typical uncomplicated patient” with pneumonia. It is possible that different physicians may have somewhat different conceptions of what this might be. Finally, our findings may be more indicative of generalists or those in academic settings because these groups were more likely to complete our questionnaire. However, the significance of any modest response bias is probably small because our analyses controlled for differences in medical specialty and hospital setting.
In conclusion, physicians believed that patients with community-acquired pneumonia could be safely switched from intravenous to oral antibiotics once they were able to maintain oral intake, the vital signs and mental status had stabilized, and there was no evidence of metastatic infection. However, there was considerable variation in several underlying antibiotic practice beliefs. Guidelines and pathways designed to promote more evidence-based, cost-effective approaches to pneumonia care will need to include educational strategies that address the heterogeneity in practice beliefs we observed.