TRENTON, N.J. (AP) — It's like OpenTable for medical appointments.

No waiting weeks to see a dermatologist. No sitting for hours in the emergency room. No frantic calls to find a family doctor with openings.

Online services such as ZocDoc and InQuicker are enabling patients with non-life-threatening conditions to schedule everything from doctor's office visits to emergency room trips on their laptops and smartphones — much like OpenTable users do with restaurant reservations.

Hospitals and doctors increasingly are subscribing to the services to simplify appointment scheduling for patients who dislike waiting on hold and are comfortable doing everything from shopping to banking online.

With most of the services, booking is as simple as going to a website, entering a zip code and the kind of care needed, and checking available times. Patients can get a doctor appointment within a couple days, even if they're a new patient. And the services say most patients are seen within 15 to 20 minutes of their appointment, and when an ER backs up, patients with reservations are texted to come later.

"I truly believe talking to people on the phone to schedule doctors' appointments will be something of the past very soon," says Natan Edelsburg, a New York resident who has made 10 doctor appointments through one of the biggest online medical appointment booking services, ZocDoc.

Doctors and hospitals are using such services to attract and retain patients as the health care landscape keeps getting more competitive. With the nationwide proliferation of urgent care centers and pharmacy clinics open on nights and weekends, patients have more convenient options than ever before.

The booking websites also are a way for hospitals and doctors to try to please patients at a time when they face new financial incentives to do so. Starting this year, the Affordable Care Act, which requires most Americans to have health insurance, increases or reduces the Medicare payments hospitals receive each year based on patient satisfaction and quality. That can have a significant impact: Medicare, which covers Americans 65 and older and others with disabilities, pays for 43 percent of hospital patients' care. A similar program for doctors starts next year.

"I don't think you can compete in our medical practice marketplace without being a ZocDoc participant," says Dr. Bobby Buka, a New York dermatologist who gets about 15 patients a week from ZocDoc.

EASY BOOKING

The services, which are free for patients but usually charge $200 to $300 per doctor a month, are benefiting from the focus on making scheduling easier for patients.

ER Express, an Atlanta startup, books reservations for more than 150 ERs and urgent care centers in nearly 30 states. It served more than 40,000 patients in 2014, up 300 percent from 2013.

Meanwhile, ZocDoc, which is based in New York, has more than 6 million patients per month making appointments for dentists, family doctors and 40-plus types of specialists in more than 2,000 cities. ZocDoc was started in 2007 by Cyrus Massoumi, who was frustrated trying to get care after his eardrum ruptured during a long flight and he had to wait four days to see an ear specialist.

"We think everyone in America will be booking online eventually," Massoumi says.

InQuicker had a similar origin. It also was founded by someone who had some experience with the hassles of scheduling medical appointments. Tyler Kiley, who'd spent lots of time in ERs growing up because his mom was an ER nurse and his dad a hospital administrator, started it in 2006. He says he'd seen lots of unnecessary waiting, so he created software for online check-ins.

Growth surged after current CEO Mike Brody-Waite joined in 2010, bringing his marketing expertise: InQuicker now serves 224 hospital ERs, 517 doctor practices, 126 urgent care centers, and some other medical providers. The Nashville company scheduled 302,000 appointments in 2014, up more than 80 percent from 2013, and its revenue was $7 million. Revenue is projected to reach $15 million this year, says marketing chief Stacie Pawlicki.

WIN-WIN-WIN

Doctors and hospitals say the services help attract new patients.

At Northwestern Lake Forest Hospital outside Chicago, assistant ER director Dr. Steve Edelstein says ER Express sends about 40 patients a month to his ER and the hospital's nearby Grayslake Emergency Center. A quarter are new patients, and he says those tech-savvy customers "are generally more likely to have credit cards and good insurance" than others.

"It's been nothing but a benefit," Edelstein says.

Jersey City Medical Center and its two urgent care centers rolled out InQuicker two years ago and use grew quickly. Together, they draw roughly 300 patients a month — 70 percent of them new patients — through InQuicker and their own healthstops.com site.

"It's helped a lot with patient satisfaction," says operations chief Kirat Kharode. His ER's average wait to see a doctor is 35 minutes, versus 15 or less with a reservation.

Some patients also like the benefits of booking online. Lauren Toth, 29, made an ER reservation last spring at Jersey City Medical Center when her foot swelled up and red spots covered her leg.

"When I got there, the waiting room was packed. There must have been 50 people there, and they took me in 10 minutes," recalls the Manhattan public relations representative.

Doctors advised rest and ice packs and sent her home for follow-up. Later, a dermatologist diagnosed inflamed blood vessels and prescribed medication.

"This could revolutionize the way emergency care is delivered," Toth says.