Advantage all? DTC ads boost prescription use and adherence, research finds

In the tussle between the American Medical Association (AMA) and pharma DTC advertising, new research gives ammunition to both sides.

To the AMA point that advertising results in more and possibly too many drugs on the market, the National Bureau of Economic Research study found that DTC ads increase the number of prescriptions filled. But to the pharma industry's point that ads help consumers stick with their drug regimens, the research also found that advertising increases patient adherence.

While measurement in DTC advertising--in all advertising actually--is often difficult, NBER took a unique and targeted approach to assess as exactly as possible the effect of DTC ads. By using the introduction of Medicare Part D in isolated geographic areas and concentrating on 5 drugs for chronic conditions, researchers believe they were able to isolate and determine the specific effects of DTC on prescription drug use and adherence.

They found that a 10% increase in DTC ad viewing led to a 5.4% increase in the total number of prescriptions filled for the advertised drugs. That same 10% spike in viewing resulted in an increase in drug adherence by 1% to 2.5%, NBER reported.

"We find that drug utilization is highly responsive to advertising exposure," the study asserts. "Advertising increases the take-up of drug treatments and improves compliance for existing patients. Expanded take-up of prescription drugs accounts for about 70% of the total effect of advertising, while increased use among existing patients accounts for the remaining 30%."

The researchers also noted another "important component" to the increased use and compliance of drugs in general. That is, the increase and compliance wasn't just a switch from nonadvertised brands to the pushed one. Evidence showed the ads increased use and compliance of nonadvertised drug in the same therapeutic category in similar proportions, calling the effect "substantial positive spillover."

- download the NBER study

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