Published in the November 2007 issue of Today’s Hospitalist
The patient safety literature is crowded with studies that delve into the many causes “confusing abbreviations, poor hand hygiene “of adverse events in hospitals.
But until recently, none had assessed the impact that hospitals’ capacity “whether they are full or not “have on adverse event rates. That factor is proving to be increasingly potent as workload (defined as patient volume, throughput and case severity) continues to rise.
In the May 2007 issue of Medical Care, researchers took a look at how hospital workload affects adverse event rates such as adverse drug events, wound infections and hospital-acquired infections. Researchers combed through data on more than 6,800 patients hospitalized in one of four hospitals: two large urban teaching facilities and two suburban teaching hospitals.
The good news was that researchers found that three out of the four hospitals, even though they were running at high capacity, had enough “slack” in their systems to safely function during peak periods.
At the busier of the two urban hospitals, however, where capacity often topped 100%, researchers found key differences. The study quantified the association researchers found between crowding and adverse events. For every 10% increase in occupancy at that hospital, researchers found, the rate of adverse events jumped 15%. Another troubling finding: Every 0.1% increase in the patient-to-nurse ratio led to a 28% increase in adverse events.
“Hospitals that operate at or over capacity,” the authors concluded, “may experience heightened rates of patient safety events and might consider re-engineering the structures of care to respond better during periods of high stress.”
Authors Joel Weissman, PhD, who is with the Institute of Health Policy at Boston’s Massachusetts General Hospital, and Jeffrey Rothschild, MD, MPH, a researcher at Brigham & Women’s Hospital in Boston and a hospitalist at Newton-Wellesley Hospital, spoke with Today’s Hospitalist about their findings.
The data from the four hospitals is from 2000’2001. What is your sense now of at-capacity issues?
Dr. Weissman: If anything, it may be getting worse because hospitals are busier. I just conducted a site visit at another hospital where one of the wards was at or near 100% capacity, and administrators there were worried about patient safety.
Errors depend on how much slack you have built into the system. If you have lot of empty beds and available nurses, you have slack in the system and you might be safer. But once you get a bump in flow, slack disappears, people work harder and mistakes are made.
The study found an association between crowding and higher adverse event rates. What other factors may be a cause?
Dr. Rothschild: The busiest hospital was more challenged than the others. It turns out that had more impact on adverse events than at the other hospitals, where capacity ran at 85% and stretched to 90%.
Another explanation for the higher rate of adverse events was that this busy hospital had sicker patients. It is possible that busy hospitals with very sick patients are at a greater risk for adverse events when overcrowding occurs. We did not look at whether the adverse events were preventable, nor did we look to see if there was an error in the event.
What are the implications of your findings?
Dr. Weissman: If a hospital finds itself very crowded, it must look carefully on those crowded days, pay attention to adverse events and re-engineer care processes.
Hospitals should look at individual units and possibly shift patients away from those areas or stop admitting patients into those units when occupancy rates become too high. Hospitals should also make sure they have enough staff on board to take care of those patients when they are at or near 100% occupancy.
There are also implications for researchers. There have been a lot of studies done on strategies to reduce errors, but those studies have been conducted on strategies for days or times when the hospital is less crowded rather than more crowded. Researchers should test interventions at peak workload pressure rather than average volume.
You recommend that hospitals “re-engineer” care processes to respond to high capacity levels. What types of re-engineering do you have in mind?
Dr. Rothschild: Hospitals may need to have a better mechanism to adapt to times of day or days of the week when they are crowded.
It is difficult to control occupancy, but you can modify or postpone elective surgery, for instance. Hospitals are hesitant to do that because they don’t want to inconvenience patients or physicians. It also may affect income because patients may go elsewhere for services.
All hospitals should agree that under certain conditions, they’ll postpone elective surgery. Or when a hospital has no beds available and emergency departments go on bypass, certain patients may need to be discharged earlier.
What are other examples of re-engineering to consider?
Dr. Rothschild: Flexible nursing pools are one way to give supervisors the freedom to bring in staff when individual hospitals realize they are at capacity and staff believe conditions are less safe. Most hospitals have a mechanism for increasing the population of doctors and nurses under some conditions, like disasters. There may be a need for policies to increase staff when hospitals reach at capacity.
Dr. Weissman:We have suggested that hospitals go to flexible nursing pools, but to say they need more nurses doesn’t mean they can get them. A hospital may need to improve the quality of its staff by getting more educated and experienced staff, and improving retention.
What about hospitals that are full or at capacity on a seasonal basis?
Dr. Rothschild: I suspect hospitals that have seasonal variations plan for it. My great fear is for unplanned variations like a catastrophic event in a community where all hospitals are challenged.
What is the implication of the study for hospitalists?
Dr. Weissman: You need to identify patterns of care and outcomes before you know what to do. Hospitalists should look at how workload varies and monitor adverse events to see if there is a relationship. They should ask for more diversions if that is possible when the occupancy rates get up to the upper 90s.
Dr. Rothschild: In many hospitals, hospitalists now head up the patient safety and quality improvement initiatives and committees. They need to realize that two key hospital goals “increasing efficiency and improving patient safety “may be in direct conflict.
To be efficient, a hospital has to be full, but once a hospital nears 100% occupancy, we found that adverse events increase. This is something hospitalists have to look at more closely.
Jay Greene is a freelance writer specializing in health care. He is based in St. Paul, Minn.
