CHICAGO - First-day jitters come with any new job but when the work involves pushing needles into strangers' bellies, stitching up gaping wounds or even delivering babies, that debut can be especially nerve-wracking - for everyone involved.

Brand-new doctors often launch right into patient care within weeks of graduating from medical school. To make sure their skills are up to snuff, many medical schools and hospitals run crash courses in the basics for these new interns.

It's called boot camp at Northwestern Memorial Hospital and its adjoining Feinberg medical school, a program involving two to three days of intense practice before letting the newbies loose on patients. Young doctors are tested on a variety of skills, from the proper technique for handling newborns during childbirth - make sure the head comes out slowly - to delivering bad news - use empathy, eye contact and listen to the patient.

More than 90 percent pass the first time. The rest are tested again until they do.

"Don't do that on Mr. Smith," instructor Dr. Jeffrey Barsuk told this year's batch of residents, warning them not to withdraw too much fluid from the belly of a mannequin patient supposedly sick with liver disease. Barsuk was showing the group how to insert a scary-looking 5-inch needle and remove abnormal fluid buildup. Taking too much can be dangerous for sick patients.

Dr. Diane Wayne, the medical school's vice dean of education, created the program in 2011, aiming partly to combat the so-called "July effect." Many experts say it's more myth than reality, and evidence is mixed, but a few studies have found lapses in patient care - even deaths - when new interns start making rounds in July.

"We have great residents who come from all over the country, but we have no reliable way of knowing that these interns possess these skills," she said. "We just don't want to subject patients to newly minted residents" with uncertain expertise.

The program won a 2012 innovation award from the Association of American Medical Colleges. The association's Dr. Robert Englander said the boot camp is part of a trend in doctor-training as hospitals increasingly focus on patient safety.

"We're looking more and more at what we can do toward the end of medical school to optimize that preparation," he said.

Bennet Butler, 26, just got his doctor degree from Northwestern and was among about 100 grads in this summer's just-finished boot camp. He gave it high marks on his first day.

"We're learning a lot already," said Butler, 26, after a refresher course on identifying surgical instruments. "We've had a couple of lectures, a couple of sessions where we were able to practice some of our skills like tying knots and suturing so, so far so good."

Butler said he's excited but anxious about starting his residency.

"This is something I've wanted to do my whole life," Butler said. "You'd have to be crazy not to be a bit nervous," he added. "It's a big upgrade in responsibility."

One of the toughest - and most praised - sessions was a test in handling end-of-life discussions, using actors trained to portray dying patients. First, the new doctors watched rapt as Northwestern ethics expert Dr. Kathy Neely demonstrated with an actor posing as single father with advanced cancer, worried sick about what would happen to his 12-year-old son.

It was like a well-acted play, with the audience straining to catch every word and nuance as Neely sat close to the "patient," touching his arm and talking gently about the burdens of choices he faced, including entering hospice care.

Then residents were sent into private hospital rooms to be tested on discussing "do not resuscitate" orders and how long to use life-saving ventilators with other fake patients.

"It was difficult going in because we were giving bad news to the patient and discussing end of life goals," said Namita Jain, 25, another recent Northwestern graduate.

Facing her first day on the job, Jain said she was most nervous about "probably, like everything," but praised boot camp for helping build up her confidence. "It's nice to be able to practice."