If you've got the sniffles or need a shot, do you go to the doctor or stop in at a clinic in a nearby drugstore?

Lots of people are opting for the clinics, which are springing up inside grocery stores, big-box retailers and chain drugstores across the country. There are already 1,388 clinics like these in the U.S., according to data from Merchant Medicine, a consulting firm.

Drugstore chain CVS, which owns MinuteClinic, is the biggest operator with 588 clinics nationwide, Merchant Medicine's October report says. Walgreens is next with 356 clinics. Wal-Mart comes in third with 143 clinics.

We were curious to know how people feel about the clinics, which are usually staffed by nurse practitioners or physician assistants. So we asked in the latest NPR-Truven Health Analytics Health Poll.

Overall, we found that people are open to the idea of trying the clinics. And those who have used them seem to like them a lot.

About half the people polled said they were aware of a retail clinic in their community. About half said they didn't know of one.

Around two-thirds of people were open to trying a clinic, regardless of whether they knew about one in the area or not.

"I think this is a reflection of the war cry that health care consumers have had for a long time," said Dr. Ray Fabius, chief medical officer at Truven Health. "They're frustrated with an inability to easily access care." Often they can't get appointments, he said, or they have a problem after hours.

A 2009 study found retail clinics were cheaper sources of care than doctors' offices, and the quality of treatment didn't appear to be worse. Another study published last month found that people who went to clinics may be less likely to see a primary care doctor for future care of acute medical conditions.

So what about the people in our poll who had been to a clinic in the last six months? Eighty percent were happy with the experience. Only 4 percent were either dissatisfied or very dissatisfied.

A cold or other minor illness was the most common reason for a clinic visit. People also went to get a flu shots or other immunizations.

We were curious about whether people who'd tried a clinic also had regular doctors. Almost all of them — 89 percent — did.

Nearly two-thirds of clinic customers told us their insurance covered the visit. A majority said they paid $25 or less out of their own pocket.

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