All-Cause Mortality From COPD Higher in Urban Areas, Lower-Income Neighborhoods

All-cause mortality is disproportionately higher in patients with chronic obstructive pulmonary disease (COPD) living in urban areas and lower-income neighborhoods, according to a study published in International Journal of Chronic Obstructive Pulmonary Disease.

The researchers emphasized that most COPD studies focus on individual patient risk factors and that fewer are population based and include community risk factors.

“Identifying both individual and community risk factors associated with higher mortality in people with COPD is essential to improve outcomes,” the authors wrote.

Consequently, the researchers identified neighborhood socioeconomic status and urbanicity as possible factors associated with differences in disease severity and related mortality. They noted that “the variation in death rates among patients with COPD has not been assessed across the urban­­­-rural gradient.” They also explained that few studies examining community risk factors within COPD mortality include race.

“To address this gap in knowledge, we used geographically precise patient-level data from a large cohort of patients with COPD to describe the associations between demographic characteristics and socioeconomic status with all-cause mortality,” the authors wrote.

The study population consisted of all patients enrolled in the Veteran Health Administration (VHA) with at least 1 International Classification of Diseases, Ninth Revision or 10th Revision codes for COPD between 2016 and 2019. The researchers obtained demographic characteristics, comorbidities, and geocoded residential addresses; they used the addresses to classify each patient’s Area Deprivation Index and rurality before assessing the association between these characteristics and age-adjusted all-cause mortality.

Using their criteria, the researchers identified over 1 million patients with COPD, 33.4% of whom had died as of January 2021. The study population consisted of a male patient majority (95.5%), and the White (78.3%) and Black (13.2%) patient populations resembled the racial breakdowns observed in the general US population. Also, most of the cohort lived in urban areas (58.8%), and 39.5% and 1.6% lived in rural and highly rural areas, respectively.

Through age-adjusted models, the investigators found an association of all-cause mortality with Black race (odds ratio [OR], 1.09; 95% CI, 1.08-1.11) and higher neighborhood disadvantages (OR, 1.30; 95% CI, 1.28-1.32). After adjusting for all covariates, including comorbidities, gender, and socioeconomic status, the association between all-cause mortality and Black patients with COPD reversed, and these patients had a reduced risk of death (aOR, 0.98; 95% CI, 0.96-0.99). The researchers noted that this implies that race alone does not determine all-cause mortality and that other factors influence it.

They also associated lower odds of all-cause mortality with female sex (OR, 0.67; 95% CI, 0.65-0.69), Asian race (OR, 0.64; 95% CI, 0.59-0.70), and living in a highly rural area (aOR, 0.92; 95% CI, 0.89-0.95).

Overall, the researchers found that all-cause mortality in patients with COPD is disproportionately higher among individuals living in lower-income neighborhoods and urban areas, “suggesting the impact of social determinants of health on COPD outcomes.”

Despite their findings, the researchers identified several limitations to their study, one being that their population was predominately male. Since they created their population based on those receiving care in the VHA, they explained that the cohort is biased toward male patients, limiting the capacity to make conclusions about the female patient population.

Because of the discrepancies in their findings in terms of race, the researchers concluded by explaining that future research should “focus on exploring mechanisms by which disparities arise and developing interventions to address these,” namely in Black patients with COPD.

Reference

Robichaux C, Aron J, Wendt CH, et al. Sociodemographic and geographic risk factors for all-cause mortality in patients with COPD. Int J Chron Obstruct Pulmon Dis. 2023;18:1587-1593. doi:10.2147/COPD.S406899