A CVS employee removes tobacco products from store shelves last month. (AP Photo/CVS Health)

CVS's decision to stop selling tobacco products this year boosted its positive press, if not its sales; the company expects the move will cost about $2 billion in annual revenue. But the decision was part of a larger play to brand itself as a company focused on health care.

The pharmacy retail giant revealed Monday it's taking another significant step in its anti-tobacco effort. Caremark, the pharmacy benefits management arm of CVS, will soon require "some customers" to make a $15 co-payment on prescriptions filled at other pharmacies that sell tobacco products, the Wall Street Journal reported Monday.

The new plan plays into the company's efforts to strike lucrative partnerships with health-care systems who value having healthier patients. The new co-pay strategy does two things. It encourages CVS customers to fill prescriptions at CVS-owned pharmacies to avoid possible co-pays. It also puts financial pressure on other pharmacies in the Caremark network to abandon tobacco sales if they haven't already. More than 54,000 pharmacies are in Caremark networks, including more than 20,000 independent community pharmacies, according to CVS.

After the company's initial announcement that it would end tobacco sales, some of its pharmacy benefit management clients asked about developing a tobacco-free network, according to CVS spokeswoman Carolyn Castel. It's still in the process of identifying which pharmacies don't sell tobacco products, Castel said.

"For clients who choose a tobacco-free network, plan members would be provided with a full list of participating pharmacies in advance of any network change," Castel said in an e-mail. "A tobacco-free network would include CVS/pharmacy and Target nationally as well as other local or regional pharmacies including numerous independent pharmacies that do not sell tobacco products."

How big a difference is CVS going to make by going tobacco-free? New research published today suggests that removing tobacco from store shelves cuts off an easy access point for patients who face some of the highest risks from using these products. Analyzing 18 months' worth of data from patients who received pharmacy benefits through CVS, researchers at Brigham and Women's Hospital found just how often people were buying tobacco products while also filling a prescription for something that indicated they really shouldn't be using tobacco.

The researchers looked at purchasing habits for customers who filled a prescription for anti-hypertensive, asthama or chronic obstructive pulmonary disease medications, as well as oral contraceptives for women at least 35 years old since smoking increases their risk of heart disease. They found 6 percent of people getting asthma or COPD medication also made at least 1 cigarette purchase within the same week. The rate was just slightly lower for users of antihypertensive medication (5.1 percent) and those buying oral contraceptives (4.8 percent).

"The decision of some pharmacies, including CVS, to stop selling cigarettes has been met with widespread support from public health and medical organizations," the researchers wrote in the study, published in JAMA Internal Medicine. "Similar actions by other pharmacies may help prevent cigarette purchasing by individuals at greatest risk.”

The research was funded by an unrestricted grant from CVS to Brigham and Women's Hospital. The company had no other role in the study.

Removing tobacco from retail pharmacy shelves makes it harder for people to buy these products, but it of course doesn't stop them from visiting another store to make that purchase. Still, previous research from CVS found laws in Boston and San Francisco banning tobacco sales at retail pharmacies were associated with 13 percent fewer purchasers in those cities.

But anti-smoking advocates estimate that 375,000 retail locations across the country still carry cigarettes and other tobacco products. The new CVS announcement comes on the same day the Campaign for Tobacco-Free Kids is launching a new offensive pressuring retailers to end tobacco sales. The group is offering a new online tool pinpointing which stores do and don't sell tobacco, hoping that customers will vote with their feet.

There's no indication yet, however, that CVS's direct competitors are about to follow in the company's footsteps.

This post has been updated up with a response from CVS and the JAMA Internal Medicine study.