Abstract
Background Social deprivation impacts chronic disease and acute admission outcomes. In interstitial lung disease (ILD), prior British Thoracic Society registry data for idiopathic pulmonary fibrosis have shown high deprivation was associated with poorer long-term outcomes. However, its impact on acute admissions in ILD is not known.
Methods We undertook a multicentre, retrospective study of ILD-related admissions between 1 January 2017 and 31 December 2019 across 11 hospitals in the North West of England, using available real-world data. We determined social deprivation geographically by the 2019 English Indices of Deprivation deciles. The primary outcome was 90-day all-cause mortality.
Results 999 admissions met the inclusion criteria. 327/999 (32.7%) of admissions came from individuals geographically in the most deprived 20%. Across 999 admissions, in unadjusted survival analysis, we observed a non-linear relationship between deprivation and 90-day all-cause mortality. In complete case multivariate modelling, deprivation demonstrated borderline significant association with all-cause mortality (HR 1.038, 95% CI 1.00 to 1.077, p=0.050). However, this effect was lost in pooled analysis using multiple imputation (HR 1.001, 95% CI 0.971 to 1.033, p=0.924). Male sex and pre-admission long-term oxygen were consistently associated with increased 90-day all-cause mortality across both models. Lower transfer factor for carbon monoxide values were significantly associated with increased 90-day mortality in pooled analysis.
Conclusion We observe a high burden of acute ILD-related hospital admission among the most deprived 20%, suggesting geographical deprivation may impact acute healthcare seeking behaviours. Once admitted, the impact of deprivation appears more complex and multifactorial. Further studies which assess geographical and individual-level deprivation are needed to validate our findings.