Social determinants of health on all-cause and cause-specific mortality in US adults with chronic obstructive pulmonary disease: NHANES 2005-2018

Abstract

Background: Social determinants of health (SDoH) are nonmedical societal factors that influence health outcomes. However, their relationship with mortality risk in patients with chronic obstructive pulmonary disease (COPD) remains poorly understood. This study aimed to evaluate the association between SDoH and the risk of all-cause and cause-specific mortality in COPD patients.

Methods: Data from seven National Health and Nutrition Examination Survey (NHANES) cycles (2005-2018) were analyzed. Kaplan-Meier survival curves and multivariate Cox proportional hazards models were used to assess the association between SDoH and mortality outcomes, including all-cause and cause-specific mortality. The sensitive analyses were performed to check the robustness of the main findings. Nonlinear relationships were explored using restricted cubic spline (RCS) analysis, offering greater flexibility than traditional linear models. Subgroup analyses further assessed the consistency and robustness of findings across different demographic and clinical factors, enhancing the depth and reliability of the results.

Results: Among 1,551 COPD participants, 506 deaths occurred, including 114 from cardio-cerebrovascular diseases and 130 from cancer. Higher SDoH scores were inversely associated with survival outcomes. After adjusting for confounders, individuals with higher SDoH scores had increased risks of all-cause mortality (hazard ratio [HR] = 1.199, 95% confidence intervals [CI]:1.136, 1.264), cancer mortality (HR = 1.236, 95% CI: 1.100, 1.388), and cardio-cerebrovascular mortality (HR = 1.143, 95% CI: 1.022,1.277) compared to those with lower SDoH scores. Sensitivity analyses confirmed the positive correlations between SDoH and mortality in the COPD population. Kaplan-Meier analyses also revealed worse survival outcomes for participants with higher SDoH scores. The agreement between survival analyses and statistical modeling underscores the predictive value of SDoH in this population.

Conclusion: The results of our study indicate a notable positive correlation between SDoH score and the likelihood of mortality from all causes and specific causes in patients with COPD.

Fig 1. The flow chart of the included participants in this study.

Fig 2. Kaplan-Meier survival curve of all-cause mortality (A), cancer mortality (B), and cardio

−cerebrovascular disease mortality (C) by SDoH.

Fig 3. RCS for the association between SDoH and the probability of all-cause (A), cancer mortality (B) and cardio

−cerebrovascular mortality (C) in patients with COPD.

Fig 4. Stratified analyses of the associations between SDoH and all-cause mortality (A), cancer mortality (B), cardio−cerebrovascular mortality (C).

Adjusted for drinking status, smoke, DM (except for grouping covariates). Abbreviations: CI, confidence interval; HR, hazard ratio. Abbreviations: SDoH, social determinants of health; COPD, Chronic Obstructive Pulmonary Disease; BMI, body mass index; DM, diabetes mellitus; CVD, cardiovascular disease.