ANTIBIOTICS are an indispensable weapon in every physician’s arsenal, but when prescribed unnecessarily for nonbacterial infections like the common cold, as they too often are, they provide no benefit and create problems. They wipe out healthy bacteria and can cause side effects like yeast infections and allergic reactions. Worse still, they contribute to the rise of “superbugs” that resist antibiotic treatment.

The Centers for Disease Control and Prevention estimates that about half of outpatient antibiotic prescriptions in the United States are unnecessary. It also estimates that each year as many as two million Americans suffer from antibiotic-resistant illnesses, and 23,000 die as a result.

Clearly, we need to get doctors to prescribe antibiotics more selectively. But how can this be done?

Several strategies have been tried in recent years, without much success. Educating doctors and patients about the proper use of antibiotics has had only a modest effect, as most doctors already know when antibiotics are called for. Alerts sent to physicians through the electronic health record reminding them to not prescribe unnecessarily are often ignored because doctors are overloaded with such messages. And offering doctors financial incentives has had mixed results, in part because the payments are modest relative to a doctor’s salary.