The common tool used to assess which chronic obstructive pulmonary disease (COPD) patients are most in need of a lung transplant may underestimate how long people survive if they do not get new lungs.
The findings, published in the journal Chest, suggest that the tool, called BODE, might cause physicians to make incorrect treatment decisions, calling for transplant physicians to evaluate new, and potentially more accurate measurements. The study reporting the findings is titled “Survival of Lung Transplant Candidates with COPD.”
“Our research shows that we are often transplanting people who may not actually derive a survival advantage at all, and we may be shortening the lives of some people with [a] transplant,” Robert M. Reed, MD, the study’s first author said in a press release. Reed is an associate professor of medicine and a pulmonary and critical care specialist at the University of Maryland Medical Center,
BODE is short for Body mass index, airflow Obstruction, Dyspnea (shortness of breath) and Exercise capacity. The tool was introduced in 2004, and has been widely used to estimate survival without a lung transplant, thereby identifying patients who are most in need of a transplant.
“While the BODE score was and remains to be a valuable prognostication tool in COPD, it has not been validated for this particular purpose,” said Reed.
Together with Bartholome R. Celli, MD, of the Brigham and Women’s Hospital in Boston, who originally developed the BODE score, as the senior study author, Reed and his team compared survival data from two groups of COPD patients.
One group was made up of the original 625 patients used to develop BODE. The second was composed of 4,300 lung transplant patients. The earlier group was made up mainly of men (only 7 percent were women), whereas the newer, and larger, group had similar numbers of male and female patients.
The new analysis revealed that BODE appears to overestimate the risk of death in lung transplant candidates with COPD. Patients lived significantly longer than the BODE score predicted.
Researchers believe that the main cause for this is that COPD patients in the BODE group had relatively few other diseases, such as cancer and heart disease, which are known to increase the mortality risk. These patients also were not active smokers.
Patients with cardiovascular disease or cancer, and those who are smokers, are not eligible for transplant.
“Statistically, a lung transplant is a risky thing,” said Reed. “About half of people are dead 5–6 years after a lung transplant due to transplant complications, so, obviously, you don’t want to transplant people who are likely to live longer if left alone.”
While concluding that the BODE score is not accurate, the study did not identify a better way of predicting survival without or after a transplant. This is a topic that the transplant community should look into, Reed said.
Nonetheless, the team underscored that other factors besides survival may influence the decisions of both patients and physicians considering a transplant.
“Dr. Reed and his team are to be commended for shedding light on some of the issues that attend when the BODE score is used to project the survival of lung transplant candidates with COPD,” said E. Albert Reece, vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of its medical center.
“This study suggests it may be worthwhile to weigh the value of new standards that take into account current transplant center screening practices,” Reece concluded.