Depression Predicts Lung Transplant Quality of Life
ATLANTA -- Duke University Medical Center researchers have shown that depression is a significant predictor of worse quality of life and perceived shortness of breath in patients awaiting lung transplantation. The negative effects of depression are above and beyond other factors, such as lung function and the underlying disease, they said.
Additionally, the researchers believe that efforts to treat the depression could possibly improve the outcomes after lung transplantation. While their study focused on patients awaiting transplantation, the researchers say that what they are learning about depression could also help other patients with severe lung disease, such as the estimated 16 million Americans who suffer from chronic obstructive pulmonary disease (COPD).
"These findings represent an example of how psychological factors can impact physical health," said pulmonologist Scott Palmer, M.D., medical director of Duke's lung transplantation program. "The effect of depression is quite striking in predicting a lung patient's quality of life as well as their perceived shortness of breath.
"The findings also suggest that while we have many medical treatments for these patients, if we don't address the issue of anxiety and depression we might have less impact on their quality of life, and possibly their ultimate outcomes," Palmer added.
Palmer prepared the results of the Duke study for presentation today (May 20) during the 98th annual international conference of the American Thoracic Society.
Their report is the first analysis of data being collected on patients awaiting lung transplants enrolled in a five-year, $2.6 million trial funded by the National Heart, Lung and Blood Institute. The trial's goal is to determine whether a telephone-based program of stress and anxiety reduction conducted prior to transplant has any effect on outcomes after surgery. During the course of the trial, Duke and Barnes-Jewish Hospital at Washington University, St. Louis, the two largest lung transplant centers in the U.S., plan to enroll 600 patients.
"Patients waiting for a transplant are under so much stress and anxiety," said collaborator James Blumenthal, Ph.D. "They worry about when the call will come or whether they'll survive the operation. In most cases, patients must relocate to the transplant center to wait for an available organ, which takes them away from their usual emotional support systems."
For this "snapshot" of the psychological and physical status of the first 99 patients enrolled in the trial on Duke's waiting list, patients took a battery of tests to measure their depression and anxiety, as well as questionnaires covering quality of life issues for lung patients and perceived shortness of breath.
The median number of days that patients had been on the waiting list was 77 days. Nationally, patients awaiting lung transplant wait an average of 18 months from the time they are listed to undergo the operation.
The researchers then performed statistical analyses to determine which of the following variables seemed to best predict quality of life and shortness of breath issues: social support, depression, gender, age, time on waiting list, underlying disease and lung function.
"Our analysis suggests that while lung function and underlying disease are important predictors of pulmonary quality of life and shortness of breath, depression appears to be a stronger predictor," Palmer said. "We need more studies to evaluate different interventions to see if they have any impact on quality of life and post-transplant outcomes."
The current trial, whose results should be available in two years, will be the first to gauge whether psychological interventions can improve the outcomes of lung transplant patients. Other possible interventions include medications or exercise, which has been proven effective in treating depression. The researchers add that there is an integral link between psychological status and lung function.
"Often, when a lung patient is short of breath, he or she becomes anxious or agitated, which can then cause them to breathe faster and shallower ? it can then quickly become of vicious cycle," Blumenthal said. "Anything we can do to lessen the degree of anxiety for lung patients should be of benefit to their perceived quality of life."
Duke performed its first lung transplant procedure in 1992. In the ensuing 10 years, the Duke program has become the largest in the country, having performed more of the surgeries than any other program in each of the past two years.
Other members of the Duke team were study coordinator Priti Parekh, Ph.D., Elizabeth Gullette, Ph.D., Michael Babyak, Ph.D., R. Duane Davis, M.D., and Mark Steele, M.D.