Reduced Adherence With Narrow Networks? CVS Says Otherwise

The Policy Research Group at CVS Health has published results from a retrospective analysis of pharmacy claims data of over 200,000 patients receiving care for chronic conditions such as diabetes, high blood pressure, high cholesterol, and depression during a 1-year period. Their prescription coverage was through CVS Health’s pharmacy benefit management business, CVS/Caremark. The comparison was between patients who chose narrow pharmacy networks and those who selected an open network. The study found that narrow network plans actually improved patient medication adherence compared with those who filled prescriptions from out-of-network pharmacies.

Narrow networks are a means used by both pharmacies and health plans to curb drug expenditure. With narrow or in-network pharmacies, there is greater flexibility to negotiate lower prices with health plans. These cost savings can, in turn, be passed on to the patients as lower prescription drug prices. Health plans play their part by reducing patient co-pays when they use in-network pharmacies, which also increases the network’s prescription volume.

While restricted networks have been blamed for adherence woes, these results from CVS prove otherwise. The outcome measure of the study was medication possession ratio (MPR), defined as the percentage of time a patient has access to medication. MPR over a 1-year period—prior to implementation of narrow networks in 2012 and after implementation in 2013—was greater for narrow network plans among all the chronic disease medications analyzed (statins, antihypertensive medications, antidiabetic medications, and antidepressant medications). Also, 90-day prescription programs, where patients receive a 3-month supply of their medication during a single visit, further improved adherence in patients used a narrow network.

"There are few opportunities in healthcare when we can improve both quality of care and health outcomes while helping to manage healthcare costs," said William H. Shrank, MD, MSHS, senior vice president and chief scientific officer, CVS Health and a study author in a press release. "This first-of-its-kind study suggests that narrow networks may be one such opportunity by providing clear evidence that these networks—already an established cost management strategy—also help optimize members' adherence."