Even though Rosalee Jones considers herself in good health and able to live on her own, she takes four different pills each day, and sometimes a fifth for arthritis pain.

The 67-year-old retired school bus driver says she avoids prescription medicine whenever possible. “A lot of people, every time something happens to them, they want a pill,” she says. “I try not to take them.”

That appears to be a prudent course. Mistakes with prescription drugs are a leading cause of death or injury in the United States, and a new study finds that older patients are most at risk because they typically have more medicines and more doctors.

Patients over 65, who often have chronic conditions and see several doctors, had a drug error rate nearly seven times greater than those under 65, according to an analysis released Wednesday. The review was done by Medco Health Solutions Inc., one of the nation’s largest prescription benefit managers.

Experts like Dr. Richard London in Milwaukee say the findings show that “people with multiple health problems need to have a physician who is the quarterback.”

More drugs, more risks
In the study, errors were flagged when a patient was prescribed a drug that was incompatible with medicines already being taken; when a drug could exacerbate another medical condition; or when an incorrect dosage was prescribed, said Dr. Glen Stettin, a Medco senior vice president.

“Clearly, the more medications you take, the more potential there is for them interacting with each other,” Stettin said. “With more physicians providing care to patients, more prescriptions are being written — however, there is clearly a communication breakdown between prescribers.”

Doctors who treat older patients said while the analysis is not surprising, it underscores the need for each patient to have a central repository of medical information. Several health providers offer that, with experts citing the all-electronic records of the Veterans Administration as a model.

Although pharmacies cross-check for potentially dangerous interactions when filling a new prescription, that is not enough, experts said. Pharmacies may not know all of a patient’s medical conditions nor may they be aware of other drugs the patient is taking. The Medco analysis found that nearly one-fourth of the seniors filled prescriptions at three or more pharmacies.

The number of doctors seen by a patient also plays a role in medication errors. Seniors who got prescriptions from two doctors got an average of 27 prescriptions a year and were at risk of 10 errors on average; those with five doctors got an average of 42 prescriptions annually and were at risk for 16 errors, the analysis found.

Having multiple doctors is not unusual — almost a quarter of seniors get prescriptions from five or more doctors, according to Medco’s analysis of drug insurance claims from 2.4 million adults in 2004.

'Pay attention to the way you feel'
Jones, the retired bus driver, takes pills to treat her high blood pressure, high cholesterol, water retention, and to replace potassium lost from the water pills. She now sees only one doctor and has only one pharmacy, and she said both are aware of all her prescriptions and conditions.

“Believe it or not, I don’t have a lot of things wrong with me,” said Jones, who moves easily with a walker but wants to lose some weight. She spends her days at the Home Sweet Home senior center in Elizabeth.

A mother of three and grandmother of seven, Jones recalled only one bad experience with prescriptions — she got “loopy” on two medications for high blood pressure. The symptoms abated when one drug was eliminated.

Her advice to seniors: “Pay attention to the way you feel” after taking a new prescription, and read the instructions when you get the medicine from the pharmacy.

A primary care physician should be aware of all patients’ prescriptions and medical conditions, even if that doctor is not treating some of those conditions, said London, who is medical director of senior health at Wheaton Franciscan Healthcare in Milwaukee.

The issue is particularly critical for elderly patients, whose multiple medical issues are often complicated by short-term memory problems and lower tolerance to medication, London said.

Dr. John R. Burton, director of the Johns Hopkins Geriatric Education Center in Baltimore, said a patient visit is a chance for the doctor to determine if any prescriptions can be dropped.

“Your priority each visit has to be a review of the medicines,” he said. “That’s what I think quality primary care demands.”