A new study suggests that lowering insurance co-payments, which is a way of providing consumers with a financial incentive, may be not enough to encourage compliance to take a chronic med. A study in the American Journal of Managed Care found that decreasing copay resulted in a 2.5 percentage rise in compliance, an increased described as modest.

The study, which was conducted by Express Scripts, the pharmacy benefits manager, looked at the compliance following a decrease in copays and demand for statins after the patent on Merck’s Zocor cholesterol pill expired in 2006 (here it is).

Greater response to increases in copays than to decreases is supported by one of the most well-documented principles of behavioral economics: aversion to losses, according to an Express Scripts statement. Under this theory, the PBM says, “patients have a more pronounced demand response when required to increase their contribution as opposed to when they pay less than their usual cost.”

So what should employers consider? The PBM has an answer wrapped in a sales pitch: encourage home delivery of meds, a service promoted by PBMs. Not surprisingly, Express Scripts cites another study showing compliance was seven percentage points higher for patients taking cholesterol meds when they used home delivery instead of a retail pharmacy. In other words, why bother lowering the copays? Pocket the money and just give back a slice to those patients who use home delivery. Hmmm…..