Study finds late-career docs prescribe longer antibiotic courses

A large retrospective study of family physicians in Canada has found that prolonged antibiotic treatments are common, especially among physicians in the later stages of their career.

The study, published in Clinical Infectious Diseases, looked at antibiotic courses prescribed over the course of a year by more than 10,000 family physicians in Ontario, Canada's most populous province, and found that more than one third of the courses exceeded 8 days. Physicians in practice more than 25 years were the most likely to prescribed prolonged courses, and, to a lesser extent, physicians in rural areas and those with large pediatric practices.

The findings are significant because numerous studies have shown that shorter antibiotic courses, especially for the type of common bacterial infections frequently treated by family physicians, are just as effective as prolonged courses, associated with fewer adverse effects, and could reduce selection pressure for resistant bacteria.

"Decreasing unnecessary antibiotic consumption through shorter durations of therapy is a potentially effective strategy to reduce bacterial resistance," researchers from the Ontario Public Health and the University of Toronto write in the paper.

Courses frequently exceed 8 days

The retrospective cohort analysis looked at family physician prescribing in Ontario from March 2016 through February 2017 using a large healthcare database, health insurance claims, and antibiotic sales data. The primary outcome was prolonged duration, defined as more than 8 days of therapy. Most common community bacterial infections can be treated in 4 to 8 days.

In their evaluation of factors that might predict prolonged prescribing, the researchers looked at physician career stages, defined as years since graduation from medical school. Career stages were categorized as early (less than 11 years), mid (11 to 24 years), and late (more than 25 years). They also looked at regional characteristics (urban vs. rural) and practice characteristics (including size of practice and age, gender, and complexity of patients).

The results showed that 10,616 family physicians, 77.2% of them in mid  or late career, prescribed a total of 5.6 million oral antibiotics over the 12-month period. The most common treatment length was 7 to 8 days (median 38.4%, interquartile range [IQR] 26.3% to 51.3%), followed by 9 to 10 days (25.2%, IQR 14.8% to 38.2%), and 5 to 6 days (17.5%, IQR 5.4% to 25.5%). An average of 35.4% of antibiotic prescriptions were for courses lasting longer than 8 days.

A bivariate analysis showed that 30.5% of the antibiotic courses prescribed by early-career physicians were more than 8 days, compared with 34.4% for mid-career physicians and 38.6% for late-career physicians. Multivariable analysis showed that late-career physicians were nearly 50% more likely than early-career physicians to prescribe prolonged courses (adjusted odds ratio [AOR], 1.48; 95% confidence interval [CI], 1.38 to 1.58], and mid-career physicians were 25% more likely (AOR, 1.25; 95% CI, 1.16 to 1.34).

The multivariable model also revealed a slightly higher likelihood of prolonged treatment by physicians in rural versus urban practices (AOR, 1.15; 95% CI 1.01 to 1.30), physicians with more comorbid patients (AOR, 1.06; 95% CI 1.01 to 1.12), and physicians who saw more children (AOR 1.20; 95% CI 1.16 to 1.25 for boys and AOR 1.12; 95% CI 1.08 to 1.16 for girls).

Stewardship training in medical school

The authors of the study say the finding that late-career physicians are more likely to prescribe longer-than-necessary courses suggests that antibiotic stewardship education needs to start in medical school, before poor prescribing behavior is established.

"While age and experience may sharpen some skills, e.g. surgery performance, it may just harden other preferences into habits," they write. "Hence, the training stage in medical school is a crucial period for shaping behavior in prescribing as it provides the basic education for future professionals before acquiring habits."

They also suggest providing more educational materials on appropriate antibiotic durations for community physicians, along with peer-comparison interventions, such as audit and feedback.

In an accompanying commentary, Noah Wald-Dickler, MD, and Brad Spellberg, MD, of the Los Angeles + University of Southern California (LAC + USC) Medical Center and USC's Keck School of Medicine, note that the finding that late-career physicians prescribe longer courses is not necessarily surprising. They say it could reflect training in "the previous era of tremendous hubris regarding the invincibility of antibiotics," before the notion of antibiotic stewardship had been introduced.    

They caution, however, that younger physicians shouldn't be let off the hook, since the study found that early-career physicians still prescribed prolonged antibiotics often. "Thus, when it comes to years of practice, perhaps it may be most accurately concluded that that we all perform similarly poorly, with some more poorly than others," Spellberg and Wald-Dickler write.

Spellberg and Wald-Dickler also argue that increased stewardship training in medical school needs to be bolstered by interventions that can help overcome inappropriate prescribing decisions driven by fear. One approach they suggest is the Expected Practice strategy, a psychological approach in which a group of primary and specialty care providers at a hospital sets standards of care that are stronger than clinical guidelines. Other providers are expected to comply with those standards or explain their decision to deviate from those standards in the medical record.

Spellberg and colleagues last month published a study at LAC + USC Medical Center that showed an Expected Practice strategy around short-course antibiotic therapy was associated with a significant reduction in antibiotic usage.

See also:

Jan 7 Clin Infect Dis study

Jan 7 Clin Infect Dis commentary

Dec 3, 2018, CIDRAP News scan on Expected Practice study

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