That's the highest estimate to date, and it's not universally accepted. Still, a large body of evidence suggests that safety issues are widespread and of special relevance to seniors, who tend to be sicker and more vulnerable than other patients.
Fortunately, there are many things that people can do to help ensure their safety while in the hospital. The key is to be an active participant in your care. Here's a basic checklist compiled from Consumer Reports, the National Institute on Aging, the Agency for Healthcare Research and Quality, Emory University Center on Health Outcomes and Quality and consumer advocates.
Research the hospital your doctor recommends and the procedure you're set to have. Check Medicare's Hospital Compare website (hospitalcompare.hhs.gov) for information about medical centers' performance. Some states publish hospital report cards, another source worth checking.
Ask your doctor how many procedures of this kind she's done, what results she usually achieves and how often potential complications occur (for instance, how often do people having hip replacements get infections?).
Get help, be organized
Arrange for a family member, friend or private nurse to serve as your eyes and ears in the hospital. Ask a doctor to serve as your care coordinator. This can be the physician who admitted you, a medical specialist, or a "hospitalist" (a doctor whose expertise is caring for people in the hospital).
Keep a notebook and have your advocate record the names of all the doctors involved in your care and what they said. Make sure you understand your diagnosis and treatment plan. Write down questions you want to ask a doctor in between visits.
Have on hand a concise summary of your medical history: all medical conditions, any surgeries or other medical procedures you've had, and all your medications.
Bring contact information for your primary care doctor and a list of people you want contacted in an emergency. Make sure you have eyeglasses, your dentures and your hearing aid with you.
Bring a list of all the medications you're currently taking, including over-the-counter drugs and supplements. Make sure that you note any allergies, previous adverse drug reactions, or bad experiences with anesthesia.
If you're prescribed new medications while in the hospital, ask doctors to explain what they're for and potential side effects. Write down the names and doses in a notebook. Speak up if you don't get medication when you should.
Be sure you understand which drugs you're supposed to take when you're discharged. Have a friend or family member fill those prescriptions immediately. Ask about drugs you have at home and whether you should take them. Tell your primary care doctor about newly prescribed drugs.
Don't get up without assistance if you're told to stay in bed. Sit for a minute and make sure you're steady before you get up. Make sure that things you need — the phone, the nurse call button — are in reach when you get back into bed. If you're feeling dizzy or if your room is dark and you can't see, ask for help before getting up.
Bring disinfecting wipes and have someone use them to wipe down surfaces that other people touch: your phone, your bed rails, the grab bars in the bathroom, the toilet seat. Do this several times a day.
Watch nurses, doctors and aides who come into your room to see if they washed their hands with soap or used a hand sanitizer before touching you. If not, say politely that you need them to do so to ensure your safety.
Make sure providers check your identification bracelet each time before you get a medical treatment, test or medication.
If you have a urinary catheter in place, a common source of infections, ask every day if the catheter is still needed or if it can be removed. If you're at a teaching hospital and a young doctor in training is providing care, make sure you know whom to talk to if you have concerns. Insist that a more senior doctor come to examine you if you're worried about how you're being treated.