Re-hospitalisation predicts poor prognosis after acute exacerbation of interstitial lung disease

BACKGROUND: Several markers have been identified to increase the risk for acute exacerbation of interstitial lung disease (AE-ILD) or mortality related to AE-ILD. However, less is known about the risk predictors of ILD patients who have survived AE. The aim of the study was to characterise AE-ILD survivors and investigate prognostic factors in this subpopulation. METHODS: All AE-ILD patients (n = 95) who had been discharged alive from two hospitals located in Northern Finland were selected from a population of 128 AE-ILD patients. Clinical data related to the hospital treatment and six-month follow-up visit were collected retrospectively from medical records. RESULTS: Fifty-three patients with idiopathic pulmonary fibrosis (IPF) and 42 patients with other ILD were identified. Two thirds of the patients had been treated without invasive or non-invasive ventilation support. The clinical features of six-month survivors (n = 65) and non-survivors (n = 30) did not differ in terms of medical treatment or oxygen requirements. Of the patients, 82.5% used corticosteroids at the six-month follow-up visit. Fifty-two patients experienced at least one non-elective respiratory re-hospitalisation before the six-month follow-up visit. In a univariate model, IPF diagnosis, high age and a non-elective respiratory re-hospitalisation increased the risk of death, although re-hospitalisation was the only independent risk factor in a multivariate model. In six-month survivors, there was no statistically significant decrease in pulmonary function test results (PFT) examined at the follow-up visit compared with earlier PFT examined near the time of AE-ILD. CONCLUSIONS: The AE-ILD survivors were a heterogeneous group of patients both clinically and in terms of their outcome. A non-elective respiratory re-hospitalisation was identified as a marker of poor prognosis among AE-ILD survivors.