Low Health Literacy is Associated with Inferior Survival Following Lung Transplantation

Purpose: Inadequate health literacy (HL) has been associated with poor healthcare outcomes.[1-3] While lung transplant (LT) recipients may be particularly vulnerable, the impact of low HL on LT outcomes remains unexplored. In the present work, we assessed the potential association of community-level HL on long term survival following LT.

Methods: All first-time, isolated LT recipients ≥18 years were tabulated from the 2004-2022 Organ Procurement and Transplantation Network. Census tract-based community HL estimates were derived from the National Assessment of Adult Literacy, an in-person assessment conducted in a nationally-representative sample.[4] Patients were stratified by HL score based on the range for the entire United States, with Highest considered >254 and Lowest ≤235/280points. To facilitate comparison, we elected to compare only the Lowest and Highest records for analysis.

Outcomes were assessed using Kaplan-Meier time-to-event analysis and multivariable Cox proportional hazard models. Variables were selected using the least absolute shrinkage and selection operator to minimize bias, and included: age, sex, race/ethnicity, insurance coverage, body mass index (BMI), ventilator dependence, extracorporeal membrane oxygenation use, prior cardiothoracic surgery, functional status, indication for transplant, donor age, donor sex, donor BMI, donor comorbidities, and ischemia time.

The primary outcome was death at 5- and 10-years following transplantation.

Results: Of 31,040 LT recipients included for analysis, 5,012 (16%) were of Lowest HL, while 3,016 (10%) comprised the Highest. On average, patients of Lowest HL were more commonly Black (18 vs 3%, P< 0.001), Hispanic (22 vs 2%, P< 0.001), and insured by Medicaid (10 vs 5%, P< 0.001), relative to Highest. Notably, Lowest HL demonstrated longer time on the waitlist, as compared to Highest (60 [18-179] vs 54 days [16-162], P< 0.001). Recipient characteristics are reported in Table 1, with national HL distribution demonstrated in Figure 1A.

A stepwise relationship between increasing HL and survival was noted (Figure 1B). Upon adjusted analysis with Lowest HL as reference, Highest HL was linked with greater survival at 5- (HR 0.88, CI 0.82-0.96) and 10-years (Highest 0.90, CI 0.84-0.97) (Figure 1C). Highest HL was also associated with reduced graft failure at 5-(HR 0.87, CI 0.82-0.96) and 10-years (HR 0.90, CI 0.84-0.97) (Figure 1D).

Following entropy balancing, Lowest HL remained linked with greater hazard of mortality and graft failure at 5- (Mortality HR 1.09, CI 1.03-1.15; Graft Failure HR 1.09, CI 1.03-1.15) and ten-years (Mortality HR 1.10, CI 1.05-1.15; Graft Failure HR 1.10, CI 1.05-1.15).

Conclusion: After adjusting for relevant variables and entropy balancing, our study is the first national analysis to demonstrate an independent association between HL and inferior survival following LT. Notably, HL stands as a modifiable factor driving disparities. Therefore, efforts to improve HL in this population may offer long-term clinical benefit.

Identify the source of the funding for this research project: None