Study links long hours, nurse errors
What they've long known about truck drivers, airplane pilots and doctors, researchers also are discovering about nurses: Those who work more than 12 straight hours make more mistakes.
Nurses who worked shifts lasting at least 12.5 hours were three times more likely to commit an error, such as giving a patient the wrong medicine or the wrong dose, than nurses who worked less than 8.5 hours, about a regular shift, according to a new study from the University of Pennsylvania School of Nursing.
Nurses reported that they committed errors on 103, or five percent, of the 2,057 longer shifts and made near errors on 97 of those longer shifts. Near errors are errors nurses intercepted before they reached patients, such as bringing the wrong medication to a patient's bedside but catching the mistake before injecting it. Meanwhile, nurses made errors on just 12, or 1.6 percent, of the 771 regular shifts, and near errors on only 20 of those shifts.
Working unplanned overtime at the end of a shift also increased the likelihood of making a mistake, regardless of how long the shift.
Ann Rogers, the lead author of the study published today in the journal Health Affairs, said many of the 393 nurses surveyed wrote commentary in their logbooks. "They often said, 'I am trying to do too much. I triple checked myself three times because I knew I was tired,' or 'it was 4 a.m. and I wasn't concentrating,' " Rogers said. "That's a bad time for any human being to be awake."
The study is part of growing concern over nurses' workloads and work hours, which may be increasing because of a national shortage of nurses and because of financial pressures on hospitals to trim staff. Researchers have studied the effect of long hours on other professions for years. Medical residents, or doctors in training, are working under new rules to limit their hours to 80 a week and not more than 24 hours straight. Already, in Massachusetts, nurses are asking the state to stop hospitals from requiring them to work overtime. Meanwhile, research into the effect of fatigue on nurses-who provide the most direct patient care--is relatively new.
Two years ago, another University of Pennsylvania study found that every time an extra surgical patient is added to a nurse's workload, her patients' chances of dying within 30 days rose by 7 percent. Their odds of suffering irreversible complication also increased.
Last November, the Institute of Medicine, a nonprofit nonpartisan advisory group, said that nurses' long work hours pose one of the most serious threats to patient safety, as fatigue slows reaction time, saps energy, and diminishes attention to detail. In its report "Keeping Patients Safe: Transforming the Work Environment of Nurses," the group said that state regulators should pass laws barring nurses from working more than 12 hours a day and 60 hours a week--even if nurses want to work extra hours to earn extra money.
Rogers and her colleagues found that 14 percent of nurses worked at least 16 straight hours at least once during the month-long study, and that the longest shift was 23 hours, 40 minutes. A regular shift typically lasts between 8 and 12 hours.
"It's unequivocal from studies in other industries that when people reach that period of 12 hours, they no longer function in their usual capacity and errors go up," said Dr. Andrew Kramer, a member of the Institute of Medicine and head of the Division of Health Care Policy and Research at the University of Colorado in Denver.
"That's why all these other industries have substantial regulations. You've probably sat on the runway waiting for another pilot, because the airline wouldn't let you pilot fly any more hours," he added. "In health care, we don't do that."
In Massachusetts, which has more than 47,000 nurses who work in hospitals, work hours have become a contentious issue between nurses and administrators, and have led to strikes. At least 42 percent of Massachusetts nurses work part-time, according to one federal study, which puts more pressure on hospitals to assign full-time nurses longer shifts, contends the Massachusetts Nurses Association, a nurses' union.
The association has pushed the Legislature to bar hospitals from requiring nurses to work overtime, but hospitals have fought the measure, saying they need flexibility during emergencies. And in many cases, hospital executives and nurses said, nurses want to work extra hours so they can work fewer days a week.
"We'll try everything else to deal with the situation, but you can't abandon the patient," said David Smith, director of health data analysis and research for the Massachusetts Hospital Association.
In its study, the University of Pennsylvania School of Nursing asked 393 registered nurses to keep detailed daily logbooks for one month during 2002. The nurses, who worked full time in hospitals across the country, recorded how long they worked each day, their overtime, whether they got dinner breaks, how much coffee they drank, if they felt sleepy driving home, and if they committed an error, or almost did.
The researchers did not ask the nurses what impact their errors had on patients, and it did not look at why nurses committed errors--because they were tired, had too many patients, were distracted because they had not returned home to their families, or other reasons. And the study relied on nurses accurately reporting their schedules and mistakes, a possible weakness of the data.
There also were some puzzling results, such as why nurses who wanted to work a 12.5 hour or longer shift reported fewer errors than those who worked more than 12.5 hours while on overtime--and fewer errors than those working a planned 8.5 hour shift.
Rogers, the study's lead author, theorized that nurses who knew their hours ahead of time purposely got more sleep, and that those working a longer planned shift had more time to accomplish tasks in an unhurried way. She and her colleagues plan to publish more results in the fall, including reports on the nurses' caffeine consumption and whether nurses fell asleep driving home from work.
Even though research into nurses' hours still is developing, many hospitals are bending to nurses demands on this front, as it's become increasingly clear that the country is grappling with an epidemic of medical errors.
Cece Buckley, 42, a nurse at Caritas St. Elizabeth's Medical Center in Brighton, said that several years ago she was ordered to work another four hours on top of her 8-hour shift--even though she was 8 months pregnant.
But this April, the nurses settled a new contract with the hospital, which says that nurses can't be forced to work more than 12 hours straight--or any overtime if they're too sick or too tired, she said. "You do get tired, that's how mistakes happen," Buckley said. "At the time, I was in the ICU, and there was no one to take my patients."
The new policy goes into effect Oct. 1. "The research on this is really starting to come out," said Debra Finch, the hospital's vice president of patient care services and chief nursing officer. "We're all interested in safety and quality."
The issue led to a 103-day strike at Brockton Hospital in 2001. Nurse Tina Russell, who was a member of the bargaining committee, said she once started work at 7 a.m. for a regular 8-hour shift and then was required to work another 8 hours. At about 10 p.m., she was tape recording an update on her patients, three of whom were diabetic. She realized afterward that she had mixed up two patients, their blood sugar levels and how much insulin they required. As a result, she asked another nurse to double-check their blood sugar and give them insulin.
The new contract allows the hospital to mandate overtime just four times a year for each nurse, Russell said, but that she rarely hears nurses complain about the issue anymore.
Liz Kowalczyk can be reached at kowalczyk@globe.com. 