Having surgery is scary enough without having to worry about exhausted surgeons, brand-new residents still green behind the ears and specialists who are off for the day. But the reality is that hospitals, like any business, have times when they’re at the top of their game — and times when they’re not.

According to a 2014 study from the American Heart Association, heart attack patients who arrive at a hospital on weeknights, weekends and holidays have a 13 percent greater risk of dying compared to those who arrive during regular weekdays. And an artery-opening procedure called angioplasty took 16 minutes longer to arrange.

Researchers explained that the catheterization lab (where angioplasty procedures are performed) is closed off-hours, and doctors off site may have to drive to the hospital to prepare the lab and set up the equipment.

Changeover in staffing may slightly undermine safety as well. In 2011, researchers at the University of California-San Francisco reviewed 39 studies related to end-of-academic-year turnover among doctors-in-training. Researchers found a 4.3 to 12 percent increase in deaths and a 0.3 to 7.2 percent decrease in efficiency of care at those transition points.

The best time to go

So if you’re scheduling a surgery in advance, when is the ideal time to have it?

“When is it safest to go to a hospital is a nuanced question,” says Seth Goldstein, MD, a surgical resident at Johns Hopkins Hospital in Baltimore and author of a 2014 study assessing times when surgeries on children are safest. “It has to do with levels of staffing, expertise, familiarity with certain problems and availability of resources such as radiology, pathology and laboratory equipment.”

Obviously, people can’t choose when to be sick — and no one should avoid getting hospital care when she needs it, says Goldstein. Variations in safety at certain times are small, he notes. But when planning non-emergency procedures, people can the following take steps to help make their hospital stays safer.

Avoid July. In July, the older, more experienced residents leave and new, less experienced ones take over. Let your doctor know your concerns and ask him when hospital staffing and efficiency are best.

Avoid nights and weekends. If you feel sick on the morning of a weekday, don’t wait until after hours to get help. “No one wants to work weekends or nights, so that’s when hospitals tend to be understaffed,” says Goldstein. “You’re putting yourself in the hospital when it’s less equipped to handle things.”

Don’t use the ER as a clinic. “It’s safer to go to your primary care physician because hospital ER doctors don’t know you,” says Goldstein. “ER physicians are particularly fearful of missed injuries so they also give more labs and tests, and every test has a potential for consequences.”

Get your flu shot. Everyone should get a flu shot at the start of fall flu season whether they’re going into the hospital or not, says Goldstein. A 2010 study at the University of Michigan found that having or catching the flu increased risk of death by .5 percent, more than the risk of weekend admission (.32 percent) and high numbers of hospital patients (.24 percent). 

Take a friend. “In a hospital, you’re sick and nervous,” says Goldstein. These factors “can make memory recall particularly poor. Have an advocate you trust who can do some fact-checking and remind you of advice you’re given by your doctor.”

Ask your friend to keep notes on who’s been in the room, what tests or medications have been ordered, what’s been done (tests, procedures) and whether you’ve gotten test results. Ask her to track even your vital signs such as blood pressure so that she can let your nurse or doctor know of any significant change.

Head off medication mistakes. For instance, take copies of your medication and supplement list with you and hand one to each doctor who prescribes a medication for you. You’ll lower the risk of drug interactions. In addition, ask your doctor what each medication is for, why you’re taking it, what side effects to expect and what to do if you miss a dose.

Dorothy Foltz-Gray is an award-winning health writer and author of "Make Pain Disappear" (Reader’s Digest Health Publishing) and "Alternative Treatments for Arthritis" (Arthritis Foundation).