Home Analysis A new view of why hospital mortality increases around the holidays

A new view of why hospital mortality increases around the holidays

December 2005

Published in the December 2005 issue of Today’s Hospitalist

For most people, December means holiday parties and time spent with families. For physicians caring for myocardial infarction (MI) in the hospital, however, the holidays mean something else entirely: an increased risk that these patients will die.

It’s a well-known phenomenon that MI patients hospitalized during the holidays don’t fare as well as patients who land in the hospital during other times of the year. While no one has ever been able to say why, researchers have focused on likely causes, from the impact of reduced staffing to the stress that patients feel during the holidays.

Now, recent research offers new insights into what may “and may not “elevate the mortality of MI patients admitted in December. And while the study provides some good news, it also raises questions about the relationship between the holidays and mortality rates.

Different care?

Researchers have long speculated that mortality among MI patients may rise during the holidays because there are typically fewer physicians and nurses working in the hospital. Previous studies, in fact, have found differences in mortality rates for patients admitted to the hospital at night and on the weekends. Researchers have attributed higher mortality rates to differences in care those patients receive, which they believe stem at least in part from reduced staffing levels.

Those studies led investigators to ask a relatively simple question: Are mortality rates higher because heart attack patients hospitalized in December don’t receive the same care as patients hospitalized in other months?

To get their answer, investigators examined well-accepted quality indicators like the use of aspirin, betablockers and percutaneous coronary intervention. Those indicators are not only part of most practice guidelines for myocardial infarction, but also pay-for-performance programs being used by payers like Medicare.

The study, which was published in the Oct. 4, 2005, Annals of Internal Medicine, found no significant differences in the type of care patients received in December. For physicians who pride themselves on keeping up to date with practice guidelines, the results are good news. While care for MI patients didn’t seem to be significantly different, investigators did find that more of these patients hospitalized in December died within 30 days. The 30-day mortality for MI patients hospitalized in December was 21.7 percent, compared to 20.1 percent for patients hospitalized during other months of the year.

The mortality difference may not be overwhelming, but Trip J. Meine, MD, lead author of the study and a private-practice cardiologist in Greenville, S.C., says it is significant. “If one out of every 50 people is dying,” he says, “that’s a big difference.”

Sicker patients

If the care of heart attack patients hospitalized in December wasn’t significantly different from the care of patients hospitalized throughout the rest of the year, what is causing a spike in mortality rates? Dr. Meine says one likely explanation can be found in the health of patients admitted around the holidays.

He points out that patients in his study’s database, for example, faced a higher risk of death. He notes that other studies have hypothesized that patients may be more likely to postpone seeking medical care during the holidays. The likely result is that most of the people who actually come to the hospital tend to be sicker and higher risk.

“My gut feeling, and this has been shown in other studies,” Dr. Meine says, “is that people delay care during the holidays. They don’t want to come in, so they’re sicker when they do come in. The people who came in over the holidays were clearly sicker than patients at baseline.” What about other plausible explanations, such as the possibility that colder weather may be a factor in MI problems around the holidays? Research has shown that there are more heart attacks during the winter months.

Dr. Meine says that a previous study found that while there was an increased number of myocardial infarctions during winter months, there was no apparent relationship to geographic region. He notes that the study helped dispel the notion that there are more heart attacks because of winter activities.

“There have been studies on both sides of the equator showing the problem is not related to shoveling snow in Boston vs. sitting on a beach in Florida,” he explains.

And what about the idea that stress from the holidays may lead to an uptick in MI mortality? Dr. Meine points to another study that looked at patients in the Los Angeles area and found more cardiovascular problems during the November and December holidays. While researchers attributed their findings to the stress of the holidays, they could not back up that hypothesis.

Clues for future research

Dr. Meine acknowledges that his Annals study didn’t definitively solve the mystery of increased MI mortality in December, but he notes that it does offer some clues that could be helpful for future studies.

He explains that investigators found some differences in key measures like the use of aspirin and PCI, but they weren’t statistically signifi cant because of the characteristics of individual patients. If a 70-year old patient was too sick to go to the cath lab, for example, the difference wasn’t valid.

But Dr. Meine wonders if similar differences might take on significance in studies of younger, healthier patients. Because these patients are typically eligible for more aggressive measures than elderly patients, Dr. Meine says, he wonders whether a study of younger patients would reveal any variations in care in December.

“It would be interesting to see if the results from this study held, or if lower risk patients were not getting the same level of care,” he explains. “The very sick often aren’t eligible for all therapies, so when you adjust for that, some differences may wash out.”

Because of these types of questions, Dr. Meine says he would like to see more research. He is confident, however, that his research does provide one important piece of the puzzle.

“Most of us thought that patient care was the big factor,” he says. “We showed that in this database, at least, the mortality rate is not related to physician or hospital characteristics.”

Edward Doyle is Editor of Today’s Hospital