Survival by procedure type after lung transplantation for COPD/emphysema

Survival after single or bilateral transplantation for COPD/emphysema was calculated using the Kaplan-Meier method, which incorporates information from all transplants for whom any follow-up has been provided. Since many patients are still alive and some patients have been lost to follow-up, the survival rates are estimates rather than exact rates because the time of death is not known for all patients.
Survival rates were compared using the log-rank test statistic.