Bridging the survival gap in cystic fibrosis–an investigation of lung transplant outcomes in Canada and the United States.

Background : Prior literature in cystic fibrosis (CF) has shown a 10-year survival gap between Canada and the US. We hypothesized that differential access to, and survival following lung transplantation may contribute to the observed gap. Objective : To compare CF transplant outcomes between Canada and the US, and estimate the potential contribution of transplant to the survival gap. Methods : Data from the Canadian CF Registry and US CF Foundation Patient Registry supplemented with data from United Network for Organ Sharing were used. The probability of surviving post-transplant between 2005-2016 was calculated using the Kaplan-Meier method. Survival by insurance status at the time of transplant and transplant center volume in the US were compared to Canada using Cox Proportional Hazard models. Simulations were used to estimate the contribution of transplant to the survival gap. Results : Between 2005 and 2016, there were 2,653 patients in the US and 470 in Canada who underwent lung transplantation for CF. The 1-, 3- and 5-year survival rates were 88.3%, 71.8% and 60.3% in the US compared to 90.5%, 79.9% and 69.7% in Canada. Patients in the US were also more likely to die on the waitlist (p Conclusions : Differences in waitlist mortality and post-transplant survival can explain up to a third of the survival gap observed between the US and Canada.