They're convenient, comparatively inexpensive -- and they're number is growing in a hurry.
According to the Deloitte Center for Health Solutions, there were just 250 such clinics nationwide in 2006. By the end of last year, there were more than 800. And it's projected that there will be more than 5,000 by the end of the decade.
But are they what the doctor ordered?
Dr. Ezekiel Emanuel, chairman of the Bioethics Department at the National Institutes of Health, examined them on The Early Show Saturday.
We used to schedule appointments with the doctor for everything from immunizations to serious illnesses. But the reality today is that a doctor's office visit can be expensive and difficult to book. With so many people without health insurance, and time at a premium, the pharmacy chains are offering the clinics as a way to fill the gap.
The clinics are usually staffed by nurse-practitioners, though more and more are being staffed by doctors.
No appointments are necessary, and most have late hours.
In a survey by Deloitte, 34 percent of consumers say they'd use a walk-in clinic, and 16 percent say they already have.
What's more, many insurance companies are now covering visits to those clinics, with much lower co-pays than they charge for visits to a doctor's office. And with a growing number of Americans living without health insurance, prices, which range from about $59 to roughly $95 for visits and preliminary exams, the clinics may be becoming a viable alternative for people in need of quick, simple treatments.
Dr. Emanuel's take on them, as told to CBS News:
WHY ARE SO MANY PEOPLE USING CLINICS RATHER THAN VISIT THEIR OWN DOCTORS?
Because they're convenient, simple and fast, bottom line.
IS IT SAFE TO USE A CLINIC THAT MIGHT BE MANNED BY A NURSE PRACTITIONER RATHER THAN A DOCTOR?
That depends in large part on what you're going for. It will certainly be less expensive and more efficient. But they break down when it comes to chronic disease or following up an illness. They are very good for acute things, but not for long-term care. The role of the nurse practitioner is decided by the state, but in some states, they can do nearly everything a doctor can in that situation, including writing prescriptions.
Use the clinics only for acute problems, such as ear infections, sore throats that may be strep throats, or vaccinations. But if you have a serious and/or chronic problem, such as diabetes, asthma, etc., see your own doctor, or go to the emergency room.
"This is about short, simple stuff," Emanuel said on The Early Show Saturday. "It's not about complicated health problems," and if you suspect or are told at the clinic that it is a more complex problem, "Go into the mainstream system" by heading for your doctor or a hospital. "This is certainly not a replacement for the doctor," he stressed.
In general, he added, "It's a little too early to tell how safe they (the walk-in clinics) are. But there is a big incentive for them to work on the safe side and follow very strict protocols for most things."
HOW CAN YOU MAKE SURE YOU'RE GETTING THE RIGHT CARE WHEN YOU GO TO A WALK-IN CLINIC?
This convenient care can be integral, but it can't be stand-alone or it won't be helpful. It's convenient for what you don't need high-tech for. As long as someone is watching the whole continuum of care, you should be OK. If you have a regular doctor and you're going to use a clinic, let your doctor know, get a printout at the clinic, and show your doctor what you've had done -- so your doctor is kept up-to-speed on all your care: "There is a concern that (clinics) will increase the fragmentation (of care) -- that you'll get a little bit here, a little bit there, and no one will have a whole picture of your health, and something could fall through the cracks," Emanuel pointed out on the show.
MANY CLINICS ARE AFFILIATED WITH HOSPITALS NOW. IS THAT SOMETHING TO CONSIDER IF YOU'RE THINKING OF GOING TO A RETAIL CLINIC?
The challenge is how to integrate this into our current medical system. Affiliation with a hospital is important, because there has to be a continuum of care. It's also important so there aren't double treatments -- if your child has his vaccine, he won't get it again if he goes to a doctor or hospital. If the clinics are affiliated with a hospital, that hospital may want to staff them with their people.
WHAT DOES THE HOSPITAL GET?
Hospitals are always looking for referrals. They look crowded because emergency rooms are crowded. People use emergency rooms for primary care, which is not how they are designed. But hospitals are trying to market themselves, to get patients to use their facilities, and this is a good way to get patients to use a particular hospital, by referral from the clinics.
ARE CLINICS OPENING THEMSELVES UP FOR POTENTIAL LAWSUITS?
Yes, certainly, it only will take one mistake, one misdiagnosis, to start a pile of lawsuits. But the clinics shouldn't get in over their heads; they should know when to send customers to a real doctor.
HOW DO DOCTORS FEEL ABOUT THE GROWTH OF THESE CLINICS?
Some still can see this as competition, can be hostile; it takes patients away. But it should be a wake-up call for doctors: We need to see care through the eyes of their patients, rather than our own, and make that care more accessible.