Longer Hospital Stays Linked To Comorbid Illnesses

Psychiatric illness prolongs the hospital stay of medical or surgical patients, studies from the 1980s have shown. And this still seems to be the case, even in this era of managed care, in which those companies exert pressure to shorten hospital stays, a new study suggests.

The investigation was headed by James Bourgeois, M.D., a professor of psychosomatic medicine at the University of California at Davis, and published in the September-October Psychosomatics.

While in this study medical and surgical patients with comorbid psychiatric disorders were found to have stayed in the hospital a markedly shorter time than did such patients in the 1980s, comorbid psychiatric illnesses other than substance-related disorders were still linked with a significantly increased length of stay.

Bourgeois and his colleagues based their study on discharge reports for some 49,000 patients cared for at the UC Davis Medical Center between 1999 and 2001. The hospital has 528 beds and no psychiatric inpatient unit.

The researchers analyzed the discharge reports to assess patients for a comorbid mental disorder. About one-third of the patients had one. Substance use, mood disorders, and cognitive disorders were the most common. Anxiety disorders, psychotic disorders, and “other psychiatric disorders” followed. Adjustment disorders were last.

Then, after taking the complexity of patients' medical and surgical conditions into consideration, the researchers compared patients with and without various comorbid mental disorders on length of hospital stay. They found that patients with no psychiatric disorder and patients with a substance use disorder had the shortest hospital stay— on average 3.29 days—whereas patients with adjustment disorders had the longest hospital stay—on average 5.68 days. Length of stay for patients with coexisting mood disorders, anxiety disorders, psychotic disorders, and cognitive disorders fell between these two extremes, with an average of 4.24 days.

In an interview with Psychiatric News, Bourgeois said that he was not surprised by the general thrust of their findings—that even with managed care, patients with comorbid psychiatric illness tend to stay longer in the hospital—since patients with a coexisting psychiatric illness tend to be difficult to treat.

However, he said that he did not expect two other results—that patients with a coexisting substance use disorder did not spend extra time in the hospital and that patients with a comorbid adjustment disorder spent the longest time there.

Regarding the first finding, he said, “I was initially a bit surprised as one often thinks of substance use disorders being associated with more medical complications, et cetera, which would presumably increase length of stay.... A possible explanation—although our dataset did not address this in detail—may be that some substance-using patients are admitted for brief inpatient detoxification and then promptly discharged, with a short length of stay.”

As for the second finding, he said, “This is indeed a curious finding, as adjustment disorder is typically not a very impairing psychiatric illness. There are exceptions, of course—for example, an adjustment disorder patient who makes a medically serious suicide attempt and thus has a long length of stay. Because there were relatively few adjustment-disorder patients versus the large size of the whole dataset, it is difficult to comment further due to the chance that few cases with very long lengths of stay among the adjustment disorder patients may have skewed the length of stay for this small group.”

Yet another noteworthy result emerged from the study. Whereas one-third of medical and surgical patients studied had a coexisting mental disorder, Bourgeois and his consultation-liaison staff were asked to formally assess only 4 percent of them. Bourgeois and his team thus hope that this finding might lead to greater involvement of consultation/liaison staffs in such cases and to more funding for consultation/liaison positions in hospitals.

The study was funded by the University of California at Davis Psychiatry and Behavioral Sciences Department.

An abstract of “The Impact of Psychiatric Diagnosis on Length of Stay in a University Medical Center in the Managed Care Era” is posted at<http://psy.psychiatryonline.org/cgi/content/abstract/46/5/431>.▪

Psychosomatics 2005 46 431