Use of Broad-Spectrum Antibiotics Rising

Nicola M. Parry, DVM

September 20, 2016

Overall rates of antibiotic use in US hospitals remained unchanged from 2006 to 2012, according to a new study. However, use of certain antibiotic classes, including some broad-spectrum antibiotics, has increased significantly.

James Baggs, PhD, from the Centers for Disease Control and Prevention, Atlanta, Georgia, and colleagues published the results of their study online September 19 in JAMA Internal Medicine.

"There were significant decreases in fluoroquinolones (20%) and first- and second-generation cephalosporins (7%) usage, but these decreases were offset by significant increases in vancomycin (32%) and agents with broad-spectrum activity against gram-negative bacteria, including carbapenem (37%), third- and fourth-generation cephalosporin (12%), and β-lactam/β-lactamase inhibitor combination antibiotics (26%)," the authors write. "Despite substantial reduction in fluoroquinolone use, this class remained the most commonly used antibiotic class in US hospitals in 2012."

Promotion of appropriate antibiotic use in the United States has become a national priority to address the public health implications associated with rising bacterial resistance to antibiotics. As a consequence, the National Strategy for Combating Antibiotic-Resistant Bacteria was released by the US government as an executive order that aims to control the problem of resistance.

Antibiotic use surveillance plays a key role in this strategy, as well as within hospital antibiotic stewardship programs identified by the Centers for Disease Control and Prevention.

"A better understanding of antibiotic use in US hospitals can inform stewardship efforts by identifying targets for reducing inappropriate or unnecessary prescribing," the authors note.

However, previous national surveys of antibiotic use in hospitals have been limited by diversity in patient populations and hospital facilities.

Therefore, in the current study, Dr Baggs and colleagues analyzed data from the Truven Health MarketScan Hospital Drug Database to estimate adult and pediatric inpatient use of antibiotics in the United States. Their analysis comprised data from approximately 300 hospitals and more than 34 million discharges, from January 1, 2006, to December 31, 2012.

Across all study years, the authors found that 55.1% of patients received at least one dose of antibiotics during a hospital stay, and the overall national days of therapy (DOT) was 755 per 1000 patient-days.

The analysis showed that overall antibiotic use did not change significantly over time (total DOT increase, 5.6; 95% confidence interval [CI], −18.9 to 30.1; P = .65).

Nevertheless, the authors identified important trends within individual antibiotic classes, including significant decreases in the use of fluoroquinolones, aminoglycosides, first- and second-generation cephalosporins, sulfa antibiotics, metronidazole (P < .001 for all), and penicillins (P = .01), with the greatest decrease seen among fluoroquinolones.

However, they also found significant increases in the use of third- and fourth-generation cephalosporins, 10.3 (95% CI, 3.1-17.5); macrolides, 4.8 (95% CI, 2.0-7.6); glycopeptides, 22.4 (95% CI, 17.5-27.3); β-lactam/β-lactamase inhibitor combinations, 18.0 (95% CI, 13.3-22.6); carbapenems, 7.4 (95% CI, 4.6-10.2); and tetracyclines, 3.3 (95% CI, 2.0-4.7).

"Our study is the first, to our knowledge, to provide national estimates of temporal trends in antibiotic use among US hospitals," the authors write, adding that this is the largest study of antibiotic use in US hospitals to date, including a wide variety of hospital types.

They also acknowledge the study's limitations, including its reliance on administrative data, which probably contained some misclassified pharmacy, clinical, and facility information.

Dr Baggs and colleagues emphasize concern about increasing use of some broad-spectrum antibiotics, and note that analyzing patterns of antibiotic use in US hospitals may have important implications for combating resistance to antibiotics.

"Our findings can help inform national efforts to improve antibiotic use by suggesting key targets for improvement interventions," the authors conclude.

Overuse Is a Psychological Problem

In an accompanying editorial, Ateev Mehrotra, MD, MPH, and Jeffrey A. Linder, MD, MPH, from Harvard Medical School, Boston, Massachusetts, stress that overuse of antibiotics is largely a psychological problem, not a knowledge problem or a diagnostic problem.

"We, as physicians, want to appear capable to our patients and not give the impression they have wasted either our time or their own," they say. "In addition, it feels easier for us as physicians to do something now rather than wait for a problem to arise."

To help reduce inappropriate antibiotic prescribing, Dr Mehrotra and Dr Linder therefore suggest three strategies. First, instead of describing antibiotic prescribing as a public health concern, they suggest presenting it as an individual patient concern: clinicians should inform patients that the harms of antibiotic use include rashes, diarrhea, Clostridium difficile infection, and harboring antibiotic-resistant bacteria for a time.

Second, they also recommend greater use of social psychology and behavioral science strategies to reduce antibiotic overprescribing. "Order entry systems that force physicians to provide a publically visible justification for prescription reduced inappropriate antibiotic prescribing from 23% down to 5%," the editorialists say. Similarly, peer comparison feedback, including informing clinicians when they are "not a top performer," makes them think about their professional reputation when they prescribe an antibiotic. In one study, "[s]uch feedback reduced inappropriate antibiotic prescribing from 20% to 4%," they add.

Third, they recommend preventing ambulatory visits whenever possible, describing office visits for colds, for example, as "wasteful, error-prone events." Instead, patients' use of self-triage Internet tools or smartphone apps could avoid many inappropriate antibiotic prescriptions.

Although clinician education and new diagnostics may help reduce the growing problem of antibiotic resistance, Dr Mehrotra and Dr Linder emphasize the need to recognize the emotional factors that drive clinicians to inappropriately prescribe antibiotics. "Future interventions need to counterbalance these factors using tools from behavioral science to reduce the use of inappropriate antibiotics," they conclude.

This study was funded by the Centers for Disease Control and Prevention. The authors and editorialists have disclosed no relevant financial relationships.

JAMA Intern Med. Published online September 19, 2016. Article full text, Editoral extract

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