US Hospitals Show No Reduction of Antibiotic Use in New 7-Year Study

*Updated with late-breaking quotes on 9/30/2016 at 3:44 PM EST.

World leaders have agreed that the first line of defense in the battle against drug-resistant bacteria and viruses is scaling back our over-prescription and abuse of antimicrobial medications. As individual nations attempt to make meaningful progress on stemming antibiotic use, a troubling new study shows that hospitals in the United States have continued to dispense antibiotics at a steady rate in recent years.

The new paper from researchers at the Centers for Disease Control and Prevention’s Division of Healthcare Quality Promotion was recently published in the Journal of the American Medical Association. Study authors pointed to the growing threat of antibiotic resistance seen in many bacterial strains today. From the Salmonella that causes food poisoning, to the Streptococcus that can result in strep throat, to the Neisseria gonorrhoeae causing the sexually transmitted disease gonorrhea, infections that were once easy to treat with antibiotics have grown stronger and increasingly resistant to treatment. Today, drug-resistant pathogens are a global problem, with many bacterial strains now no longer susceptible to multiple classes of antibiotics and approaching pan-resistance.

In the United States, antibiotic use surveillance is one of the key elements of The National Strategy for Combating Antibiotic-Resistant Bacteria as well as hospital antibiotic stewardship programs. Ensuring that antibiotics are prescribed judiciously can improve patient safety, slow the development of drug-resistant bacteria, and limit the waste of resources. As such, this study examined antibiotic use in US hospitals to inform stewardship programs and identify inappropriate or unnecessary prescribing. The last such study was conducted in 2011 and up-to-date data were lacking. To capture the diversity of patient populations and facilities, the study used a proprietary administrative data set from a large and diverse population of US hospitals to estimate patterns of inpatient antibiotic use over several years and extrapolate these findings to all US hospitals.

The study analyzed data collected from January 1, 2006, to December 31, 2012, that had been obtained from the Truven Health MarketScan Hospital Drug Database. Included were data on adult and pediatric drug use from over 34 million discharges representing 166 million patient-days from 552 total hospitals. The number of hospitals contributing data in that time period for a given year ranged from 300 to 383. For each discharge the study authors identified antibiotic doses given to the patient during the inpatient stay. Antibiotics were categorized into one of 15 classes. Estimated measures of antibiotic use were both days of therapy per 1000 patient-days (DOT) and the proportion of hospital discharges in which a patient received at least one dose of an antibiotic during their stay. The researchers performed a weighted extrapolation of data from the subset of US hospitals reporting to the database to create national estimates of inpatient antibiotic use.

The authors of the study found that overall, 55.1% of patients discharged received at least one dose of an antibiotic during their hospital visit. In that same time period, the overall rate of antibiotic use was 755 days per 1,000 patient days. The highest proportion of discharges in which an antibiotic was given during the hospital visit was for first- and second-generation cephalosporins, fluoroquinolones, and third- and fourth-generation cephalosporins. Overall usage declined for aminoglycosides, first and second generation cephalosporins, fluoroquinolones, sulfa, and metronidazole, while the use of cacrolides, third- and fourth-generation cephalosporins, glycopeptides, beta-lactam/beta-lactamase inhibitor combinations, carbapenems, and tetracyclines increased during this time.

Along with the much hoped for drop in antibiotic use that the study authors did not observe, they noted a concerning rise in the use of broad-spectrum antibiotics once reserved for a smaller number of dangerous infections. The findings highlight the work still ahead for US hospitals tasked with reducing their use of antibiotics.

“We need to improve the systems in hospitals that will support optimal prescribing through good antibiotic stewardship programs,” says James Baggs, PhD, one of the study’s authors. “We need to improve education for all healthcare providers on how to better our antibiotic use. We need to improve the availability and use of better and faster tests to diagnose infections. And we need to improve the availability and use of data on antibiotic use in all hospitals.”

“We know that providers want more information on antibiotic resistance trends that might impact which antibiotics they choose for their patients,” notes Dr. Baggs. “They also want more education, starting at earlier stages of their training, like medical school, on how to optimize their selection of antibiotics. Patients also want more information on steps they can take. We encourage patients to talk to their providers about any antibiotics they are prescribed so that they know the reason they are taking the antibiotic, exactly how and how long to take it and what side effects to watch out for.