PFF Registry News

NASHVILLE, Tenn. — People with interstitial lung disease living in rural areas do not appear to have greater risk for death, lung transplant, acute exacerbation or disease progression compared with those in urban areas, researchers reported.

“Approximately 15% to 90% of people in the U.S. live in rural areas. We do know that there are a lot of disparities in health care in general [in rural areas],” Hyun Kim, MD, associate professor of medicine and director of the Interstitial Lung Disease Program at the University of Minnesota, Minneapolis, said during a presentation at the CHEST Annual Meeting. “We know less about disparities in interstitial lung disease. Little is known about the effects of morality and outcomes in ILD or the impact of socioeconomic disadvantage in ILD.”

The researchers conducted a retrospective analysis utilizing the Pulmonary Fibrosis Foundation Registry. The study included 1,640 patients at 42 U.S. sites (median age, 67.5 years; 63.4% men). Sixty percent had idiopathic pulmonary fibrosis and 40% had non-IPF ILD. Using the area deprivation index (ADI), researchers mapped patient-reported zip codes and classified patients as living in urban or rural areas based on the U.S. Census classification. Urban areas were defined as large, median and small metropolitan areas and rural areas as micropolitan and noncore areas.

Ten percent of patients in the registry were living in economically disadvantaged areas and 13% were living in rural areas.

According to the results, younger age was associated with worse outcomes, Kim said. Patients aged 51 to 60 years had a higher risk for time to death or transplant (HR = 2.46; 95% CI, 1.44-4.22) and the composite endpoint of time to death, lung transplant or acute exacerbation (HR = 1.96; 95% CI, 1.24-3.10) and time to first respiratory hospitalization (HR = 1.97; 95% CI, 1.19-3.27).

“As people older in this cohort, the risk for these outcomes actually decreases. Age does not appear to affect risk for disease progression, in terms of decline in FVC or DLCO,” Kim said.

Male patients in this registry had worse outcomes, according to the results. Men had higher risk for time to death or lung transplant (HR = 2.57; 95% CI, 2.29-3.61), time to acute exacerbation (HR = 2.57; 95% CI, 1.47-4.49), time to death, lung transplant or acute exacerbation (HR = 2.70; 95% CI, 2.38-3.36) and time to first respiratory hospitalization (HR = 1.78; 95% CI, 1.37-2.31) compared with women.

“Males [with IPF], in general, have worse outcomes and higher mortality than females. This is maybe the first time we’ve discovered this in an ILD cohort in general,” Kim said.

When the researchers looked specifically patients with IPF, they found increased risk for time to lung transplant compared with patients with non-IPF ILDs (HR = 1.61; 95% CI, 1.21-2.15).

Results showed no difference in risk for any of the outcomes among patients living in urban areas vs. rural areas: time to death or transplant (HR = 0.91; 95% CI, 0.68-1.21), time to acute exacerbation (HR = 1.14; 95% CI, 0.68-1.9), time to death, transplant or acute exacerbation (HR = 0.95; 95% CI, 0.72-1.24), time to first respiratory hospitalization (HR = 1.13; 95% CI, 0.79-1.62), time to FVC decline of at least 10% (HR = 0.98; 95% CI, 0.78-1.22) or time to DLCO decline of at least 15% (HR = 0.9; 95% CI, 0.72-1.13), according to the presentation.

“This is surprising [because] our hypothesis was that [living in rural and economically disadvantaged areas] is associated with worse outcomes or disparities,” Kim said.

An unexpected finding, Kim said, was that “patients who live in less disadvantaged neighborhoods seemed to have a higher risk for death from lung transplant or acute exacerbation,” Kim said. “We were expecting that patients with more disadvantages would have worse outcomes. What we found was actually the opposite.”

Compared with the most disadvantaged 10%, patients who are less disadvantaged had a higher risk for time to death, lung transplant or acute exacerbation (HR = 1.65; 95% CI, 1.06-2.56).

“In conclusion, we found in the PFF Registry that patients with ILD who live in rural areas do not have a higher risk for death, lung transplant or acute exacerbation or disease progression. And, contrary to what we were expecting ... patients who live in less disadvantaged neighborhoods seemed to have a higher risk for death from lung transplant or acute exacerbation. It’s unclear why,” and perhaps may be driven by shorter time and more access to lung transplant.