Effect of Lung Transplantation on Health-Related Quality of Life in the Era of the Lung Allocation Score: A U.S. Prospective Cohort Study

Abstract

Under the U.S. Lung Allocation Score (LAS) system, older and sicker patients are prioritized for lung transplantation (LT). The impact of these changes on health-related quality of life (HRQL) after transplant has not been determined. In a single-center prospective cohort study from 2010 to 2016, we assessed HRQL before and repeatedly after LT for up to 3 years using the SF12-Physical and Mental Health, the respiratory-specific Airway Questionnaire 20-Revised, and the Euroqol 5D/Visual Analog Scale utility measures by multivariate linear mixed models jointly modeled with death. We also tested changes in LT-Valued Life Activities disability, BMI, allograft function, and 6-min walk test exercise capacity as predictors of HRQL change. Among 211 initial participants (92% of those eligible), LT improved HRQL by all 5 measures (p < 0.05) and all but SF12-Mental Health improved by threefold or greater than the minimally clinically important difference. Compared to younger participants, those aged ≥65 improved less in SF12-Physical and Mental Health (p < 0.01). Improvements in disability accounted for much of the HRQL improvement. In the LAS era, LT affords meaningful and durable HRQL improvements, mediated by amelioration of disability. Identifying factors limiting HRQL improvement in selected subgroups, especially those aged ≥65, are needed to maximize the net benefits of LT.

Keywords: clinical decision-making; clinical research/practice; epidemiology; geriatrics; lung transplantation/pulmonology; organ allocation; quality of life (QOL).

Conflict of interest statement

DISCLOSURE

The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation.

© 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Figures

Figure 1. Conceptual Model of Disablement

Proposed by Nagi(43), the pathway begins with a disease process that causes organ pathology. As this pathology becomes clinically relevant, organ dysfunction emerges, termed impairment. Impairment, in turn, leads to reductions in actions, termed functional limitations. Functional limitations may then lead to disability, defined as difficulty performing activities in daily life. Disability is an upstream precursor to and determinant of both health-related quality of life (HRQL) and mortality.

Figure 2

Flow chart of transplanted study participants over the duration of the study. LTx = lung transplantation. Study number in the left column represents the number of subjects providing data for analysis at each time point (deaths accounted for in analytic approach). Study number in the right column explains reasons for missed surveys at each time point.

Figure 3

Unadjusted plots of average health-related quality of life (HRQL) from before transplant to up to 3 years after lung transplantation for Panel A. SF12 Physical Component Summary (PCS); Panel B. SF12 Mental Component Summary (MCS); Panel C. Airway Questionnaire 20-revised; Panel D. Euroqol 5D; and Panel E. Euroqol Visual Analog Scale. The plotted line reflects the mean score and whisker bars reflect the bounds of the 95% confidence intervals at each time point. On the Y-axis, the first solid horizontal line marks the baseline mean; the dashed horizontal line reflects the minimally clinically important difference (MCID) and the solid line reflects twice the MCID. The number of subjects who contributed HRQL data, missed survey responses, and died at each time point is shown in Table S1.

Figure 3

Unadjusted plots of average health-related quality of life (HRQL) from before transplant to up to 3 years after lung transplantation for Panel A. SF12 Physical Component Summary (PCS); Panel B. SF12 Mental Component Summary (MCS); Panel C. Airway Questionnaire 20-revised; Panel D. Euroqol 5D; and Panel E. Euroqol Visual Analog Scale. The plotted line reflects the mean score and whisker bars reflect the bounds of the 95% confidence intervals at each time point. On the Y-axis, the first solid horizontal line marks the baseline mean; the dashed horizontal line reflects the minimally clinically important difference (MCID) and the solid line reflects twice the MCID. The number of subjects who contributed HRQL data, missed survey responses, and died at each time point is shown in Table S1.

Figure 3

Unadjusted plots of average health-related quality of life (HRQL) from before transplant to up to 3 years after lung transplantation for Panel A. SF12 Physical Component Summary (PCS); Panel B. SF12 Mental Component Summary (MCS); Panel C. Airway Questionnaire 20-revised; Panel D. Euroqol 5D; and Panel E. Euroqol Visual Analog Scale. The plotted line reflects the mean score and whisker bars reflect the bounds of the 95% confidence intervals at each time point. On the Y-axis, the first solid horizontal line marks the baseline mean; the dashed horizontal line reflects the minimally clinically important difference (MCID) and the solid line reflects twice the MCID. The number of subjects who contributed HRQL data, missed survey responses, and died at each time point is shown in Table S1.

Figure 3

Unadjusted plots of average health-related quality of life (HRQL) from before transplant to up to 3 years after lung transplantation for Panel A. SF12 Physical Component Summary (PCS); Panel B. SF12 Mental Component Summary (MCS); Panel C. Airway Questionnaire 20-revised; Panel D. Euroqol 5D; and Panel E. Euroqol Visual Analog Scale. The plotted line reflects the mean score and whisker bars reflect the bounds of the 95% confidence intervals at each time point. On the Y-axis, the first solid horizontal line marks the baseline mean; the dashed horizontal line reflects the minimally clinically important difference (MCID) and the solid line reflects twice the MCID. The number of subjects who contributed HRQL data, missed survey responses, and died at each time point is shown in Table S1.

Figure 3

Unadjusted plots of average health-related quality of life (HRQL) from before transplant to up to 3 years after lung transplantation for Panel A. SF12 Physical Component Summary (PCS); Panel B. SF12 Mental Component Summary (MCS); Panel C. Airway Questionnaire 20-revised; Panel D. Euroqol 5D; and Panel E. Euroqol Visual Analog Scale. The plotted line reflects the mean score and whisker bars reflect the bounds of the 95% confidence intervals at each time point. On the Y-axis, the first solid horizontal line marks the baseline mean; the dashed horizontal line reflects the minimally clinically important difference (MCID) and the solid line reflects twice the MCID. The number of subjects who contributed HRQL data, missed survey responses, and died at each time point is shown in Table S1.