A new study, by researchers at the Rollins School of Public Health and Saint Louis University found that antibiotic resistance added $1,383 to the cost of treating a patient with a bacterial infection in the United States in 2014. This cost amounted to a national treatment cost of approximately $2.2 billion in that year. The study will be released ahead of print by Health Affairs.

Led by, Kenneth E. Thorpe, PhD, professor and chair of health policy and management, Rollins School of Public Health, the authors analyzed data from the Medical Expenditure Panel Survey (MEPS) for the years 2002–2014 and estimated the incremental health-care costs of treating a resistant infection as well as the total national costs of such treatment. According to the authors, while the number of bacterial infections remained relatively constant, totaling 13.5 million in 2002 and 14.3 million in 2014, the share of these infections that were antibiotic resistant rose from 5.2% to 11.0% in the same period. This study is believed to be the first national estimate of the costs for treating antibiotic-resistant infections.

“An important feature of this study is that it shows that the vast majority of patients with antibiotic-resistant infections are not given the appropriate ICD-9-CM diagnosis codes,” the authors concluded. “This underuse of codes makes it difficult to detect the infections and…uncover the infections’ true prevalence and burden.”