BACKGROUND: Frailty status can help predict outcomes in lung transplantation candidates1,2,3. However, due to the limited amount of data regarding the best method for assessing frailty in lung transplant candidates or recipients, it has been difficult to implement a universal frailty measure into clinical practice. In this study, we compared two frailty assessments with each other and a known determinant of lung transplantation outcome, the lung allocation score (LAS).
OBJECTIVES: Examine the relationship of a chart-based frailty index and a prospective Short Physical Performance Battery (SPPB) score with 1) each other and 2) a lung transplant candidate’s medical urgency and expected post-transplant survival rate, as measured by the lung allocation score (LAS).
METHODS: We evaluated a cohort of 22 UCLA patients who were accepted as lung transplant candidates between 2014 and 2018. A chart-based frailty index composed of 14 domains to capture elements of functional health-related deficits including weight loss, fall risk, cognitive impairment, mood disorders, and others, was derived by medical chart data extraction. The SPPB score was assessed at the initial lung transplant candidacy evaluation and included objective measures of gait speed, balance, and chair stand testing. The LAS score was calculated for each patient based on pre-transplant data. The association of the two frailty scores with each other, as well as with LAS, was evaluated using a Pearson correlation analysis.
RESULTS: Of the 22 lung transplant patients, 54.5% were male. The most common etiology of end-stage lung disease was idiopathic pulmonary fibrosis (36.4%). Two of the lung transplant patients had missing SPPB scores, 1 had a missing LAS, and 0 had missing retrospective frailty index scores. The average SPPB score was 8 (± 3), the average chart-based frailty index was 5 (± 2), and the average LAS was 45 (± 15). The chart-based frailty index and the SPPB were statistically correlated (r2=0.19, p= 0.05). Both of the frailty assessments were statistically correlated to LAS. However, SPPB had a stronger correlation with LAS (r2= 0.40, p < 0.01) than the chart-based frailty index (r2=0.20, p=0.04). There was no correlation between age and the chart-based frailty index (r2=0.0005, p=0.92) nor the SPPB (r2=0.04, p=0.37).
CONCLUSIONS: Functional health-related deficit data gathered during a comprehensive transplant candidacy assessment may be an appropriate surrogate marker of physical frailty. Additionally, physical frailty and functional health-related deficits may be more strongly related to severity of lung disease than age. Studies to determine the prognostic role of these frailty assessments prior to lung transplant are ongoing.
- Carswell, A. L., et al. “Frailty Assessment in Lung Transplant Candidates: The Use of the Short Performance Physical Battery.” The Journal of Heart and Lung Transplantation, vol. 37, no. 4, Apr. 2018, p. S120. Crossref, doi:10.1016/j.healun.2018.01.285.
- Singer, Jonathan P., et al. “Frailty Phenotypes, Disability, and Outcomes in Adult Candidates for Lung Transplantation.” American Journal of Respiratory and Critical Care Medicine, vol. 192, no. 11, Dec. 2015, pp. 1325–34. Crossref, doi:10.1164/rccm.201506-1150OC.
- Wilson, Michael E., et al. “Pretransplant Frailty Is Associated with Decreased Survival after Lung Transplantation.” The Journal of Heart and Lung Transplantation, vol. 35, no. 2, Feb. 2016, pp. 173–78. Crossref, doi:10.1016/j.healun.2015.10.014.