Government policies designed to reduce the use of antimicrobial drugs need more rigorous evaluation so that the lessons they offer can be better understood and used, say researchers who reviewed studies on a wide range of policies tried out in many countries around the world.
The researchers found 69 studies that described 17 different kinds of policies used by governments to limit antimicrobial use in the name of preserving the drugs' effectiveness, according to their report, published yesterday in PLOS Medicine. But few of the studies used rigorous enough methods to confidently assess the policies' effectiveness, the authors said.
The team, led by Susan Rogers Van Katwyk, PhD, of the University of Ottawa as first author, included members from Canada, South Africa, and the United States.
Many study designs used
The authors searched seven databases to identify the 69 unique studies of government policy efforts, which were conducted in four of the six World Health Organization regions. Only 4 of the studies were randomized controlled trials. Of the rest, 35 involved "rigorous quasi-experimental designs," and the other 30 involved uncontrolled and descriptive designs. The most common design (25 studies) was the interrupted time series, in which multiple observations are made before and after an intervention.
The most common policies used were informational strategies (35 studies), including public awareness campaigns and antimicrobial guidelines for healthcare workers, which were widely used in most regions, the researchers found. Another 27 studies examined regulatory steps, such as changing prescribing rules, while 3 addressed legislation and 3 looked at financial measures.
Most of the policies examined targeted healthcare workers (44 studies) or both health workers and the public (13); 12 were aimed only at the public.
Regional policy patterns
Some of the policy approaches were concentrated in certain regions, the authors said. For example, seven studies examined policies or laws requiring prescriptions for antibiotics in Latin American countries where the drugs had previously been available over the counter. In addition, China, South Korea, and Taiwan tried a number of regulatory approaches, such as requiring hospitals to post their antibiotic use rates online and penalizing physicians who ignored prescribing guidelines.
A few studies examined policies in Canada and Europe whereby national health insurance plans didn't reimburse patients for the cost of antibiotics unless their physicians met certain guidelines, such as proving the existence of an infection.
The researchers do not point to any particular policy as clearly effective or universally applicable. "Since most of these 17 policies have been evaluated only once or twice and in particular contexts, it would be unwise to draw strong conclusions about their effectiveness," they write, adding that many were evaluated using "low-quality, non-randomized designs."
They also note that they found no studies of certain antimicrobial-reduction policy ideas that have been commonly discussed, such as "creating human-only classes of antimicrobials, banning direct-to-consumer advertising, and using tax or fiscal measures."
The authors conclude that governments have a variety of policy options for addressing antimicrobial resistance (AMR). "However, we also note that most existing policy options have not been rigorously evaluated, and some commonly discussed policy options have not been evaluated for their impact on antimicrobial use. To avoid wasting public resources, governments should ensure that future AMR policy interventions are evaluated using rigorous study designs and that study results are published."
Noting the study's limitations, the researchers said they could not assess the actual impact of government policies on human health, given the complexity of the links between AMR, the use of antimicrobials in humans, animals, and agriculture, and health outcomes.
Jun 11 PLOS Med study