We trust hospitals with our lives. Sometimes that trust is misplaced. A remarkable 25% of all hospitalized patients will experience a preventable medical error of some kind. Here are seven things your hospital might not tell you…

Your surgeon has experience—just not with the operation you require. A recent study by researchers at the University of Michigan found that surgical death rates are directly related not to a surgeon’s overall experience but to his/her experience with the particular operation being performed. Depending on the operation, trusting a surgeon who performs your procedure only rarely could make you four times more likely to die than you would be with a surgeon who performs it regularly.

What to do: Ask your doctor how many times each year he performs the operation you need and how that figure compares with other doctors in his specialty. Call the office of another doctor in this specialty as well, and ask how often he performs this operation. You don’t necessarily need to select the doctor who performs the operation the most, but be cautious about one who performs it far less than the average.

You can’t trust marketing claims. Hospital advertisements often promote the facility’s “number-one ranking” or say that the hospital has a “comprehensive center” for the treatment of a specific health need. Such claims often are overstated.

What to do: Read the fine print about the hospital’s advertised number-one ranking—that top-ranked status might be restricted to a very specific measure or malady that has little to do with your needs. The Web site HospitalCompare.hhs.gov provides more meaningful hospital information. If a hospital claims to have a “comprehensive center” for the treatment of your condition, ask how many patients with this condition the hospital treats, then compare that figure with other area hospitals.

Helpful: When you meet hospital workers in your community, ask which hospital they would choose if they needed care. A recent survey conducted at 60 reputable US hospitals found that in one-third of them, half or more of health-care workers would not feel comfortable receiving medical care in the unit in which they work.

Doctors recommend the procedures that they know best, not the ones that are best for you. Many operations now can be performed through minimally invasive procedures. Rather than cutting the patient open, small keyhole incisions are made in the skin, then the doctor inserts a tiny camera and long instruments to perform the surgery. The pain resulting from these minimally invasive procedures tends to be substantially less than with traditional open operations, the recovery times shorter, the risk for infection lower, the scars smaller and, in almost all cases, the odds of a positive outcome greater. But too often, minimally invasive procedures are not even mentioned to patients as an option because their doctors don’t feel comfortable performing them.

What to do: Do a Web search for the name of the operation you require, along with the words “minimally invasive.” If the results suggest that there is a minimally invasive alternative that your doctor didn’t mention, ask your doctor, “Am I a candidate for the minimally invasive procedure?”…“What are the differences in complication rates and recovery times between the open and minimally invasive procedures?” Seek a second opinion if you suspect that your doctor might be pushing open surgery for reasons that have more to do with his abilities than your needs.

The hospital’s plastic surgeons may have little or no training in those fields. A license to practice medicine is a license to do anything in any medical field—even procedures well outside a doctor’s area of training. Lately doctors trained in other specialties have been switching to plastic surgery without significant additional training because that field offers very high earnings potential.

What to do: Confirm that a plastic surgeon is certified by the American Board of Plastic Surgery (www.ABPLSurg.org).

You might be better off going to your local community hospital than a prestigious research hospital. Patients tend to assume that famous hospitals offer the best care, but patterns of where doctors go for their own care suggest that for routine health situations, patient outcomes tend to be better at community hospitals than at big academic medical centers.

What to do: Lean toward prestigious research hospitals if you have a high-risk or complex condition such as cancer, heart problems or a high-risk pregnancy…but toward well-regarded community hospitals for hernia surgery, an appendectomy and other routine conditions.

You’re probably better off with a doctor who doesn’t seem omniscient. Patients might feel more secure when their doctor seems to have all the answers, but they’re probably better off with a doctor who knows he doesn’t know everything. My research team found a strong correlation between hospitals where the staff reported good teamwork—including doctors willing to consult with other doctors—and positive patient outcomes.

What to do: Raise the topic of seeking a second opinion with your doctor. It’s a good sign if he encourages this…a bad sign if he becomes defensive.

There might be no safety net if something goes wrong during your outpatient medical procedure. Fully 38% of outpatient procedures now are done in ambulatory surgery centers that have no adjacent hospital. If something went seriously wrong during such a procedure, the patient might have to be transported to a hospital for emergency treatment—and he/she might not get there in time.

What to do: For any major surgical procedure that requires general anesthesia, choose a medical facility that is in or connected to a hospital.