Most of us know the drill: get sick, go to the doctor’s office or clinic, get a prescription, go to the pharmacy and have it filled. That’s how the system is supposed to work in many countries – and is the goal in others – where drugs including antibiotics are often dispensed without a prescription.

But does prescribing always happen the way it should? Not as often as you might think, according to a recent first-of-its-kind study of “phantom” antibiotic prescriptions, published in Infection Control and Hospital Epidemiology.1 Phantom prescriptions are those ordered by an authorized prescriber, but without a face-to-face interaction (excluding prescription refills).

The phantom designation does not necessarily mean a prescription is inappropriate, but it does raise suspicion. Up to 30 percent of all outpatient antibiotics dispensed in the United States are not considered appropriate, for a variety of reasons, including both prescriber and patient factors.2 Many people can recall an antibiotic prescription for what was just a bad cold—most likely caused by a virus, and untreatable with an antibiotic. This situation occurs strikingly often: approximately half of all prescriptions for respiratory infections are inappropriate. It may be that many phantom prescriptions fall into this category.

To find out more about phantom prescriptions, Benjamin Riedle and his colleagues tracked the records of more than 185,000 patients on Medicare over the course of a year following an acute myocardial infarction (AMI) – also known as a heart attack. They found that within the population of Medicare patients with an AMI, 52,000 (15 percent) of more than 350,000 antibiotic prescriptions filled had no evidence of a related doctor’s visit – the phantoms.

Some of these phantom prescriptions may have been for people who actually had a documented bacterial infection. If patients went to a clinic and paid cash, there would be no record of their visit in the Medicare database, and any antibiotic prescriptions could be mislabeled as phantoms. If they got their prescription from a nursing home or at the dentist, the record would not have shown up in the analysis. Some of the phantom prescriptions may actually be appropriate antimicrobial prescribing for urinary tract infections (UTIs).

The authors analyzed the data to see how critical these last three issues were, finding that antibiotics typically prescribed by dentists or for UTIs were less likely to be in the phantom category and that patients in long-term care facilities were less likely to have a phantom prescription than those who were not.

The study authors also investigated which patients in the study population were most likely to have a phantom antibiotic prescription filled. Patients who filled these scripts were more likely to be white and female, and less likely to live in a low-income or non-English-speaking area than those who filled prescriptions following an office visit. They were also generally healthier: patients who received a phantom prescription were less likely to have another AMI or stroke in the year following their first heart attack, and more likely to be alive one year after the first AMI. They were also less likely to have had a diagnosis of diabetes, chronic kidney disease or chronic obstructive pulmonary disease before the initial AMI.

What does this mean for antibiotic stewardship? Most outpatient antibiotic stewardship programs focus on what can be done to limit prescribing at the doctor’s office, but rarely address other situations where antibiotics may be prescribed inappropriately. In their analysis, the authors conclude: “it is conceivable that several tens of millions of antimicrobial prescriptions may be written without a corresponding face-to-face encounter with a healthcare provider. These phantom antimicrobial prescriptions are concerning because they are potentially immune from traditional office-based-stewardship interventions.” Drugs sold on the internet – with or without an official prescription, or even intended for livestock use – also escape capture by traditional stewardship programs, as do those illegally sold under-the-counter in some U.S. stores.

We know that phantom antibiotics exist, and thanks to this new research, we now know more about their prevalence and typical recipients, at least in the Medicare population. The study reflects continued progress on finding the gaps in antimicrobial stewardship – an important step toward devising and implementing relevant stewardship interventions.

Andrea White is a Research Analyst at CDDEP.

References

1Riedle, BN, Polgreen, LA, Cavanaugh, JE, Schroeder, MC and Polgreen, PM. Phantom Prescribing: Examining the Frequency of Antimicrobial Prescriptions Without a Patient Visit. Infection Control & Hospital Epidemiology. 2016; doi: 10.1017/ice.2016.269.

2Fleming-Dutra KE, Hersh AL, Shapiro DJ, Bartoces M, Enns EA, File TM, Finkelstein JA, Gerber JS, Hyun DY, Linder JA, Lynfield R, Margolis DJ, May LS, Merenstein D, Metlay JP, Newland JG, Piccirillo JF, Roberts RM, Sanchez GV, Suda KJ, Thomas A, Woo TM, Zetts RM, Hicks LA. Prevalence of Inappropriate Antibiotic Prescriptions Among US Ambulatory Care Visits, 2010-2011. JAMA. 2016;315(17):1864-1873. doi:10.1001/jama.2016.4151