Introduction

The decreasing effectiveness of antimicrobial agents is a growing global public health concern. Low-income and middle-income countries are vulnerable to the loss of antimicrobial efficacy because of their high burden of infectious disease and the cost of treating resistant organisms. We aimed to assess if copayments in the public sector promoted the development of antibiotic resistance by inducing patients to purchase treatment from less well regulated private providers.

Methods

We analysed data from the WHO 2014 Antibacterial Resistance Global Surveillance report. We assessed the importance of out-of-pocket spending and copayment requirements for public sector drugs on the level of bacterial resistance in low-income and middle-income countries, using linear regression to adjust for environmental factors purported to be predictors of resistance, such as sanitation, animal husbandry, and poverty, and other structural components of the health sector. Our outcome variable of interest was the proportion of bacterial isolates tested that showed resistance to a class of antimicrobial agents. In particular, we computed the average proportion of isolates that showed antibiotic resistance for a given bacteria-antibacterial combination in a given country.

Findings

Our sample included 47 countries (23 in Africa, eight in the Americas, three in Europe, eight in the Middle East, three in southeast Asia, and two in the western Pacific). Out-of-pocket health expenditures were the only factor significantly associated with antimicrobial resistance. A ten point increase in the percentage of health expenditures that were out-of-pocket was associated with a 3·2 percentage point increase in resistant isolates (95% CI 1·17–5·15; p=0·002). This association was driven by countries requiring copayments for drugs in the public health sector. Of these countries, moving from the 20th to 80th percentile of out-of-pocket health expenditures was associated with an increase in resistant bacterial isolates from 17·76% (95% CI 12·54–22·97) to 36·27% (31·16–41·38).

Interpretation

Out-of-pocket health expenditures were strongly correlated with antimicrobial resistance in low-income and middle-income countries. This relation was driven by countries that require copayments on drugs in the public sector. Our data suggest cost-sharing of antimicrobials in the public sector might drive demand to the private sector in which supply-side incentives to overprescribe are probably heightened and quality assurance less standardised.

Funding

National Institutes of Health.