Survival status one-year following lung transplant: The contribution of functional measures at time of registration by diagnosis group

Lung transplantation has become a viable option of treatment for individuals with end-stage lung disease, however demands for organs greatly outweigh the supply. One of the many challenges of transplant is choosing the best candidate for the best outcome at the best time. A new allocation system using the Lung Allocation Score (LAS) was introduced in May 2005 and changed the waiting list from a seniority to a priority system of ranking patients for transplantation. The purpose of this study was to determine the effects of the functional measures within the LAS on survival of lung transplantation at one year.; The national database from OPTN/UNOS was requested for all adult lung transplants over the age of 18 performed from May 2005 through August 2006 for analysis. A factorial MANOVA was performed on 894 records and found that there was no significant interaction between diagnosis groups of the LAS and the survival status at one year with the functional measures of the LAS. Main effects showed significant differences between survival status and diagnosis groups primarily with the six-minute walk test, body mass index and the LAS. The sensitivity, specificity and likelihood ratios were recalculated as performed in the pilot study to determine the effects of changing the six-minute walk test threshold from 150 to 800 feet, a distance close to the mean performance. For all diagnosis groups 800 feet showed the strongest evidence to predict death following lung transplant. Use of 800 feet may equalize some of the differences between the two predominant groups of patients, obstructive and restrictive. Recommendations for further research included retrospective recalculation of the LAS based on a six-minute walk test of 800 feet to determine if a higher threshold would better predict survival status. Recommendations also include introduction of functional performance or quality of life measures as standard outcome measures in lung transplantation data collection or possibly the LAS, and finally, modify or eliminate variables in the current LAS equation depending on performance of the variable over the next two to three years.