Women’s Disadvantage on Lung Transplant Waitlists May Be a More Global Problem

Women are less likely than men to get a needed lung transplant and spend an average of 6 weeks longer waiting for one, but they do better with the transplant, a French study found.

In French registry data, women waited 115 days for a lung transplant on average versus 73 days for men (PP=0.001).

However, among those who received a lung transplant, fewer women died overall during follow-up (34.4% vs 42.7%, PERJ Open Research.

“Clinicians, patients, and policymakers must acknowledge this gender difference as it’s essential for appropriate action to be taken. Early listing for women or revising allocation policy of donor lung to recipient could be considered,” Tissot said in a statement.

And it’s not just France, she said: “We believe our findings, such as the potential role of size matching and its consequence on access to lung transplantation, and length of time on the waiting list, may also apply in other countries where lung transplantation is performed.”

The findings corroborate and extend those from the U.S. transplant system. United Network for Organ Sharing (UNOS) lung transplantation waiting list data from 2005-2010 showed women were more likely than men to die or become too sick for transplantation within 3 years of listing (16.1% vs 11.3%, OR 1.58, P

Both UNOS and European lung transplant registries have a predominance of women waiting for lungs (60% and 58%, respectively), according to a 2019 review.

“Understanding the gender disparities in transplantation is a crucial first step to making patient care better for women and reducing the time they spend on the waiting list,” commented Michael Perch, MD, of Rigshospitalet in Copenhagen and chair of the European Respiratory Society’s Group on Lung Transplantation, who was not involved in the research. “There could be several reasons why women are waiting an average of 6 weeks longer than men, including differences in education and health literacy, socioeconomic differences, immunological factors, and donor-recipient size matching.”

The researchers emphasized their finding that women with oversized lung transplantation, as defined by predicted total lung capacity ratio and weight mismatch, did not have worse survival.

“Clinicians and policymakers alike must question why there is a focus on gender and size matching in transplantation when evidence shows that, in lungs, these factors do not determine a woman’s chance of survival, and it ultimately risks an increase of women dying while waiting for a transplant,” Perch said in a statement. “It is unacceptable for women to be waiting longer than men for these lifesaving donations, so effective corrective measures must be introduced.”

Size matching in France has relied solely upon height and sex, Tissot’s group noted. “This study may support a more widespread use of [donor-to-recipient predicted total lung capacity ratio] for size matching, which may be more accurate and may decrease the volume reduction number, as volume reduction was associated with reduced overall survival. As a result, it may possibly allow a higher proportion of female recipients to receive male donor transplants in a safe way and thus, addressing some of the gender inequalities on the waiting list.”

Because most of the data on gender differences in lung transplantation have come from the U.S., Tissot’s group performed a retrospective study of patients at the 12 transplantation centers in France using data from the Cohort in Lung Transplantation (COLT) database, which had started as a registry of French transplant centers and expanded across Europe.

The study included 1,710 participants (802 women and 908 men) waitlisted for lung transplant between 2009 and 2018 and followed for an average of 5.7 years after transplantation. The main underlying reason for waitlisting was chronic obstructive pulmonary disease or emphysema in most patients, followed by cystic fibrosis and interstitial lung disease.

Women entered the waitlist at a younger age on average than did men (47 vs 54 years, PPPP=0.03) and had a greater 6-minute walk test distance (45% vs 43% of predicted, P=0.03).

The main limitations of the study were the retrospective nature of the analysis, the smaller cohort compared to UNOS-based studies, a high rate of missing data for measures including volume reduction and 6-minute walking test performance, and the lack of data on reason for waitlist removal.