They are the fifth-leading cause of death in the US, claiming the lives of up to 98,000 Americans annually.

Misdiagnoses… prescription mistakes… hospital-acquired infections… and botched surgeries are among the most common causes of preventable deaths due to medical errors.

What can you do to protect yourself? To find out, Bottom Line/Health spoke with Peter J. Pronovost, MD, PhD, a patient-safety researcher at Johns Hopkins University.

Dr. Pronovost’s commitment to patient safety began more than 20 years ago when his father was mistakenly diagnosed, at age 50, with leukemia instead of lymphoma — an error that prevented him from receiving potentially life­saving treatment. Determined to make medicine safer, Dr. Pronovost has been involved in various patient-safety initiatives.

His biggest breakthrough: A checklist to eliminate deadly hospital-acquired infections. The checklist reminds health-care providers of five simple steps proven to reduce infection due to a central line catheter (placed in a vein in the neck, groin or chest to administer medication or fluids). In Michigan, where the checklist has been adopted, catheter-caused bloodstream infections have dropped by 66%. New Jersey and Rhode Island also have adopted the checklist, and 30 other states plan to do so.

For his efforts, Dr. Pronovost was recently awarded a prestigious MacArthur Foundation Fellowship “Genius Grant.”

Your father’s misdiagnosis was tragic. How common are diagnostic errors? Misdiagnosis is an enormous problem. Most of the evidence we have comes from autopsies, which show that up to 40% to 50% of the time the diagnosis was wrong. It could be that misdiagnoses are disproportionately high among patients who are autopsied. We just don’t know, because we still don’t have a good way of measuring misdiagnoses in patients before it’s too late.

What can patients do to help ensure a correct diagnosis? Take the time to articulate not only your symptoms, but also your perception of what may be wrong. Patients have wisdom. You’re living with the disease. When you are diagnosed, ask your doctor: “How confident are you in this diagnosis?” If there’s any uncertainty — and especially if there are treatments with varying degrees of risk — get a second opinion. If your doctor’s prescribed treatment is not working, ask him/her to reevaluate the therapy.

Your checklist to prevent catheter infections is said to be saving more lives than perhaps any laboratory advance of the last decade. What explains the checklist’s huge impact? The information — from the Centers for Disease Control and Prevention (CDC) — was out there, but it was inefficiently packaged. No one is going to use 200 pages of guidelines. We simplified it into the five most important actions that health-care providers can take to prevent infections.

If we create similar checklists for diagnosing common medical conditions, it’s going to make it easier for patients to communicate with their doctors so that they always get the care they’re supposed to.

Is there evidence that patients aren’t always getting the care they should be receiving? A large study published in The New England Journal of Medicine showed that, on average, for a wide variety of conditions at most hospitals in this country, patients get only half of the available interventions or therapies that might benefit them.

What can patients do about it? If you know your diagnosis, you can look up evidence-based clinical practice guidelines through the National Guideline Clearinghouse (, sponsored by the US Department of Health and Human Services’ Agency for Healthcare Research and Quality. I also hope to have checklists for many common diseases and conditions available to the public within a few years.

What can patients do in an emergency to make sure they are offered the best medicine? Help the doctor create his own checklist by asking: “What are the three most important things you can do to help me, and are you doing them?” If you are too ill to ask, a family member should do so. It will force the doctor to prioritize.

What other questions should patients ask? When your doctor recommends a therapy, ask about the risks, benefits and alternatives so you can make an informed decision based on your values. For example, if you’re taking a blood thinner and need any type of operation, the blood thinner should be stopped prior to the surgery to prevent excessive bleeding. However, discontinuing this medication raises your risk for a blood clot that could lead to a stroke. (Certain patients, such as those with a history of blood clots or a stent — a wire mesh tube used to prop open an artery — should ask their doctors whether their blood thinner should not be stopped.)

In deciding when to resume the blood thinner, we’re trading off your risk for stroke against your risk for bleeding. Most of the time, we don’t even mention those risks, but you need to know what they are because you may weigh them differently than your physician.

Are there other factors that can affect patient safety? Staffing — especially in the intensive care unit (ICU) — is crucial. Studies show that your risk of dying is 30% higher in the ICU if you don’t have an intensive care physician (who has received specialized training in treating ICU patients) looking after you. Even so, 80% of ICU patients do not have intensive care specialists. My advice: If you or a loved one is in an ICU for more than a day without an intensive care specialist, transfer to a hospital that will provide one.

Before a patient receives a central line catheter (to administer fluids or medication), health-care providers should…

  • Assess whether the catheter is necessary.
  • If yes…

  • Wash their hands with soap.
  • Clean the patient’s skin with chlorhexidine (an antiseptic).
  • Place sterile drapes over the entire patient and wear a sterile mask, hat, gown and gloves.
  • Avoid the femoral (thigh area) site (because of higher infection risk).