Interstitial Lung Diseases in Israel: Large Variability in Close Geographic Proximity

<b>Background:</b> There have been no previous comprehensive reports on interstitial lung diseases (ILD) in Israeli population, that may have unique epidemiological features. We aimed to explore ILD in Israel, with an emphasis on disparities between different regions of the country. <b>Methods:</b> The study included consecutive patients with a multidisciplinary diagnosis of ILD, using data from registries of four tertiary medical centers (MC) located in Central and Northern Israel. Multivariate regression models were used to assess the region of residence (peripheral vs. central) as an independent predictor for ILD subtypes. <b>Results:</b> Included were 927 patients with ILD (mean age 67 ± 13, 40% females). Most patients (56-61%) reported working in at least one job that involved relevant inhalational exposures. Despite the geographic proximity of MCs (all within 100 km), significant variations in demographic and clinical characteristics were observed, including age, sex, exposures, and ILD diagnoses (<i>p</i> < 0.01). The most prevalent diagnoses were Idiopathic pulmonary fibrosis (IPF, range 13-58%) and autoimmune-related ILD (11-30%). In peripheral areas, the diagnosis of IPF was more frequent (53% vs. 24%, <i>p</i> < 0.01), while exposure-related ILD (5% vs. 16%, <i>p</i> < 0.01) and autoimmune-related ILD (16% vs. 25%, <i>p</i> < 0.01) were more frequent in central Israel. In multivariate analysis, peripheral residence remained an independent predictor for IPF (AOR 2.95, 95% CI 2.1-4.1) and central residence for exposure-related ILD (AOR 0.46, 95% CI 0.33-0.63). <b>Conclusions:</b> Variations in ILD characteristics were observed between centers in close geographic proximity, highlighting disparities between peripheral and central Israel, and the need for personalized assessment based on local frequencies and exposures.