Baseline predictors of mortality in non-idiopathic pulmonary fibrosis interstitial lung disease - A retrospective cohort study at a tertiary centre in Malaysia

Background and AimsThe prognosis of interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF) has not been studied as extensively as IPF. This study aimed to evaluate baseline factors associated with mortality in non-IPF ILD, including demographic characteristics, respiratory function test (RFT), comorbidities, and ILD subtypes. MethodsThis retrospective cohort study analysed prospectively collected data of patients with non-IPF ILD at a single tertiary centre in Malaysia (2010-2023). Patients without baseline RFT or HRCT were excluded. Survival was assessed using Kaplan-Meier analysis, and mortality predictors were identified using Cox regression. ResultsThe mean age was 60 {+/-} 15 years, with a male-to-female ratio of 1:3. Indian ethnicity constituted the largest group (n = 109, 47.6%). The mean baseline forced vital capacity (FVC) was 53.3 {+/-} 21% predicted. An FVC <50% predicted, age [&ge;]50 years at diagnosis, specific ILD subtypes, and ethnicity were independently associated with mortality. Compared with Malays, both Chinese (hazard ratio [HR] 9.86, 95% confidence interval [CI] 1.27-76.89, p = 0.037) and Indians (HR 8.59, 95% CI 1.14-64.69, p = 0.001) were associated with a higher risk of death. Kaplan-Meier analysis demonstrated significant differences in survival across non-IPF ILD subtypes (log-rank p = 0.048), with hypersensitivity pneumonitis showing the poorest prognosis (mean survival 6.1 years). ConclusionEthnicity emerged as an independent prognostic factor for mortality in non-IPF ILD. The underlying mechanisms remain unclear and may reflect differences in genetic variation, cultural factors, or environmental exposures. Larger prospective studies are required to validate these findings.