Race, Income Limit CF Lung Transplant Access in US More Than Canada

Patients in the U.S. with cystic fibrosis (CF) and advanced lung disease are less likely to receive a lung transplant and twice as likely to die before having transplant surgery than their counterparts in Canada, a new study finds.

Moreover, the difference was more pronounced along race and especially socioeconomic divides, with fewer U.S. patients on income-based Medicaid or Medicare health insurance receiving lung transplants. In both the U.S. and Canada, data also show that non-white patients were significantly less likely to get a transplant.

“The current study adds to the evidence base demonstrating inequities related to income and race in the United States, which is exaggerated in this population with a chronic health condition that requires an expensive life-saving treatment,” the researchers wrote.

“Universal health insurance in Canada may be an additional factor positively affecting survival for individuals with CF in Canada,” they added.

The study, “Survival and Lung Transplant Outcomes for Individuals With Advanced Cystic Fibrosis Lung Disease in the United States and Canada: An Analysis of National Registries,” was published in the journal CHEST.

Respiratory failure is a serious complication and a primary cause of death associated with CF. The median age of survival among CF patients in the U.S. is 10 years younger than in Canada — 40.6 vs. 50.9 years — with differences in mortality rates while waiting for a lung transplant and post-transplant.

“A recent comparison of the United States and Canada showed that differences in post-lung transplant survival and transplant waiting list deaths account for one-third of the survival gap between the countries, with notable survival disadvantages for U.S. patients with [Medicaid and Medicare] insurance,” the researchers wrote.

Now, researchers investigated differences in lung transplant and mortality rates among individuals in the U.S. and Canada with advanced CF using patient data from 2005–2016.

To be included in the analysis, patients had to be at least 6 years old and have advanced lung disease, defined as two forced expiratory volume in one second (FEV1) measurements of less than 40% predicted (severely abnormal) within a five-year period. FEV1 is a measure of lung function.

A total of 5,899 patients (52.7% male) in the U.S. and 905  patients (54.1% male) in Canada were included in the analysis. The median follow-up times were 4.2 years in the U.S. and 4.3 years in Canada.

Compared with Canadian CF patients, those in the U.S. with advanced lung disease had a slightly younger median age (24.2 vs. 25.4 years), were somewhat more likely to have pancreatic insufficiency (98.1% vs. 91.3%), and were more likely to have CF-related diabetes (59% vs. 41.4%). The U.S. patients also were less likely to have Burkholderia cepacia (5.8% vs. 20.1%) — a bacterial infection common in CF patients.

CF patients in the U.S. also had more frequent supplemental oxygen use (12.3% vs. 6.2%), non-invasive ventilation use (4.9% vs. 0%), and pulmonary exacerbations.

A total of 58.1% of all CF patients with advanced lung disease in the U.S. were on Medicaid or Medicare. Of these, 75% were non-white patients.

In the U.S, 91.6% of adults (1,842) had received lung transplants, compared with 94.3% (353) of those older than age 18 in Canada. Patients in the U.S. were just as likely to receive a transplant (31%) as they were to die before receiving a one (31%). In contrast, Canadian patients were far more likely to receive transplants than to die before receiving one (39% vs. 18%).

Patients in the U.S. were 79% more likely to die without a lung transplant and 34% less likely to receive a transplant than their Canadian counterparts. 

Notably, these differences were more pronounced in U.S. patients on Medicaid/Medicare insurance, with a 2.24 times greater risk of death before transplant compared with Canadians, and a 46% decreased likelihood of receiving a transplant.

Moreover, non-white patients in both countries were significantly less likely to receive lung transplants and more likely to die without receiving one.

According to the team, this raises “concerns about underuse of [lung transplant] among vulnerable populations,” they wrote.

The study had several limitations, the researchers said, noting that there were inconsistencies in patient data collection and reporting, and the potential misclassification of markers of disease severity. Additionally, there were limitations in the lack of quality of life measures, lung transplant and waitlist information, Canadian socioeconomic measures, and data on CF patients on CFTR modulators.

Nonetheless, the data clearly indicates that CF patients with advanced disease in the U.S. have “lower rates of [lung transplant] and increased risk of death without [it]” compared with patients in Canada, the team concluded.

“Identifying differences in the use of [lung transplants] for individuals with advanced CF living in the United States compared with Canada underscores the importance of improving access to [lung transplant] in the US, including a focus on earlier referral for consideration of [lung transplant] and attention to systemic biases that may contribute to exclusion and/or worsened health outcomes,” the team wrote.