Researchers tracking the global spread of antimicrobial resistant infections may have identified a new culprit: drug co-pays.
In much of the developing world, when people can't afford medicine from government health systems, they turn to informal or black markets. The pills they buy there may be lower quality, prescribed inappropriately, or dosed incorrectly. All those factors can hasten the spread of drug-resistant pathogens.
How much people spend out-of-pocket on health care turned out to be a better predictor of antibiotic resistance than poverty, sanitation, or livestock production, according to an analysis of data from 47 countries published today in the Lancet Infectious Diseases journal.
The World Health Organization called antibiotic resistance "a growing public health threat" last year in its first major report that tallied the level of resistance in each country. It warned that "many of the available treatment options for common infections in some settings are becoming ineffective." Superbugs sicken 2 million people in the U.S. each year, killing 23,000, according to the Centers for Disease Control.
Researchers from Stanford University and Gandhi Medical College & Hospital in India used data from the WHO report to examine whether the levels of resistance in low- and middle-income countries were linked to the costs patients bear.
The theory is that when traditional health systems charge people more, patients are more likely to turn to black markets with shoddier medicine. The researchers found a meaningful association: Countries where patients paid a higher share of health-care costs had higher levels of resistance. The effect was evident only in countries that charged co-payments for drugs.
The paper doesn't prove that higher drug costs cause greater antibiotic resistance, but it shows that they're linked. There may be other, undetected factors that affect both, though in other respects, countries that charge co-pays appeared similar to those that don't.
The paper's critical insight is that in the developing world, people may switch back and forth between the established health-care system and a "robust informal private health-care sector." Co-pays are usually used to discourage people from seeking unnecessary health care. But if charging patients drives people to poorer-quality care, that should alarm public health officials—especially if it's encouraging antibiotic resistance.