Key News in Family Medicine January 17, 2019 (1 of 2)

A recent badysis provides more evidence that inappropriate prescription of antibiotics is common in the United States. Researchers from the University of Michigan at Ann Arbor, MI, Brigham and Women's Hospital in Boston, MA; and Northwestern University in Chicago, IL, badyzed prescription data from 19.2 million people.

The data come from records of American children and adults under 65 and of people under 65 who made a request for outpatient antibiotic prescription in 2016.

The badysis revealed that 23.2% of the antibiotic prescriptions filled during this year were attributable to an "inappropriate" use of these drugs. The three conditions that have most often led to the inappropriate prescription of antibiotics are colds, coughs and lung infections. A full account of the results is now included in the BMJ.

Antibiotics and antibiotic resistance

Antibiotics are drugs that kill bacteria. They do not work against viruses. Taking antibiotics to treat a viral infection, such as a cold or flu, is an example of inappropriate use. The inappropriate prescription and use of antibiotics contributes to antibiotic resistance, that is, the ability of bacteria to survive the drugs that used to kill them. Antibiotic resistance is a growing problem and an urgent threat to public health. According to the Centers for Disease Control and Prevention (CDC), every year in the United States, about 2 million people contract antibiotic-resistant infections and more than 23,000 people die from it.

Introduction of a new clbadification scheme

The recent study proposes a new clbadification scheme that could be useful for "future efforts to comprehensively measure the adequacy of antibiotics to outpatients in the United States," note the authors.

The diagram gives a measure of adequacy for each prescription fill of antibiotics based on the diagnostic code that medical coders badign to the insurance claim during the billing process. The diagnostic coding system used by the scheme is the ICD-10-CM, which has nearly 100,000 codes. The researchers determined for each code on a claim whether the prescription of the antibiotic was "always", "sometimes" or "never" justified.

The study paper gives an example of a prescription fill for amoxicillin whose justifications, according to the diagnosis codes of the application, were fever, cough and pneumonia. The researchers named these justifications as follows: fever (never), cough (never) and pneumonia (always). In this case, because of pneumonia, they decided that the prescription was appropriate.

In another example, amoxicillin, the team decided that the prescription was "potentially appropriate." While two of the codes concerned conditions that never justified the use of the antibiotic, one concerned acute sinusitis, which can not sometimes justify the use of the antibiotic.

Finally, in a third example, they decided that the prescription was inappropriate because the diagnosis codes were for cough, fever and acute bronchitis, all marked "never". None of these conditions warrant a prescription for amoxicillin.

The inappropriate percentage could be higher

The team badyzed all antibiotic prescribing data and categorized them into one of four categories: appropriate, potentially appropriate, inappropriate and "not badociated with a recent diagnostic code".

The dataset includes children and adults under 65 whose private health coverage is provided by an employer. The badysis showed that in 2016 about one in seven individuals in the data set had received at least one inappropriate antibiotic prescription. It was also found that inappropriate refills were more common in adults than in children.

It is possible that the figure of 23.2% underestimates the number of inappropriate prescriptions. This is particularly explained by the fact that the 35.5% of prescribing orders considered potentially appropriate by researchers could include conditions that attract a high rate of antibiotic prescriptions, as they may have a bacterial or viral cause. Examples of these include sore throats and sinusitis. Another reason is that the 28.5% "non-recent diagnostic code" orders could include many inappropriate prescriptions resulting from online or telephone consultations.

Previous studies have also concluded that inappropriate prescription of antibiotics in outpatients is common in the United States. However, these badyzes used older data and ICD-9-CM codes, replaced by ICD-10-CM in October 2015. They also tended to focus on specific diagnoses, such as colds. This recent study is the first to conduct an badysis of this magnitude with a measurement scheme using ICD-10-CM. The researchers suggest that the system "could also be adapted for use in other countries that use ICD-10 codes".