Neighborhood-level disadvantage negatively impacts lung function in IPF

Key takeaways:

• There was a link between Healthy Places Index percentile rises of 10% and higher FVC.
• Mortality risk went down over time with this degree of Healthy Places Index change.

Lung function of patients with idiopathic pulmonary fibrosis in California was poorer if they resided in disadvantaged vs. advantaged neighborhoods, according to results published in Annals of the American Thoracic Society.

“This translated to increased mortality risk for those with earlier disease, suggesting that early interventions to address the health effects of social determinants and less advantaged neighborhoods are critically important,” Alison M. DeDent, MD, MAS, assistant professor of medicine in the division of pulmonary and critical care medicine at University of California, San Francsico (UCSF), and colleagues wrote.

Using the 2001 to 2020 UCSF IPF Cohort, DeDent and colleagues conducted a retrospective study and evaluated 783 patients (mean age, 71 years) with IPF to find out the impact of neighborhood health on IPF disease severity and mortality.

The California Healthy Places Index (HPI), which combines 25 census-tract indicator variables pertaining to “economic[s], education, housing, access, neighborhood, pollution, transportation and social,” helped classify the neighborhood health of patients’ addresses. Total scores range from 0 to 100 for least to most advantaged neighborhood conditions.

Researchers divided up the study population into four groups based on neighborhood health.

The least advantaged group (quartile 1) included 196 patients (mean age, 70.3 years; 66.8% men; 70.1% white; 86.7% urban residence), and the most advantaged group (quartile 4) included 195 patients (mean age, 73.9 years; 78.5% men; 79% white; 98.5% urban residence). Quartile 2 (n = 196; mean age, 69.3 years; 73.5% men; 77.8% white; 86.7% urban residence) and quartile 3 (n = 196; mean age, 71.6 years; 77.6% men; 72.7% white; 95.4% urban residence) fell in the middle of the HPI scale.

Following adjustment for demographic and clinical covariates, regression models demonstrated a link between HPI percentile rises of 10% and higher FVC (1.14% predicted; 95% CI, 0.55%-1.72%), as well as higher diffusing capacity of the lung for carbon monoxide (DLCO; 0.99% predicted; 95% CI, 0.49%-1.49%).

Of the eight domains included in the HPI, researchers noted four as the main drivers of the FVC finding: economic (1.07% predicted), education (0.96% predicted), access (1.35% predicted) and social (0.77% predicted).

Similarly, the main drivers of the DLCO finding included the economic (0.94% predicted), education (0.73% predicted), access (0.89% predicted) and social (0.75% predicted) domains.

In terms of mortality, 60% of the study population died. Researchers found a significant relationship between HPI rises of 10% and a reduced mortality risk over time (aHR = 0.95; 95% CI, 0.91%-0.98%), but this link was no longer present with the additional adjustment for baseline pulmonary function measures.

The risk for death was elevated among patients with normal to mildly impaired FVC (≥ 70% predicted) and DLCO (≥ 60% predicted) in the least vs. most advantaged HPI quartile (HR = 2.91; 95% CI, 1.2-7.05) but not among patients with moderate to severely impaired FVC (< 70% predicted) and DLCO (< 60% predicted).

“Researchers, community organizations, funders and policymakers should come together to design and conduct multicenter, multiregional, prospective studies that more rigorously define and assess social determinants and other factors important to neighborhood health in patients with IPF; more robustly identify the key factors associated with poor health outcomes; and design interventions to address these factors through clinical practice and health policy,” DeDent and colleagues wrote.