PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a progressive disease. Effective treatment is not currently available and the prognosis is poor. The aim of our study was to identify clinical predictors of survival in patients with IPF.
METHODS: By using medical record database of a university hospital, we reviewed patients who had been diagnosed as IPF from January 1996 through December 2007. ATS/ERS criteria were used to diagnose IPF.
RESULTS: Among 89 patients considered as having interstitial lung disease (ILD) on computed tomography (CT) of the chest, 22 were excluded because of the diagnosis of other ILDs or connective tissue disease and finally 67 met the criteria of IPF. The mean age at the diagnosis of IPF was 70 years (41-87) and 43 (64%) were male. The mean survival time of 67 patients following the diagnosis of IPF was 40 months (0-179). Among them, 28 cases were diagnosed as the progressive state of IPF on the follow-up CT examination, and the mean duration between diagnosis of IPF and progression was 31 months. Multivariate analysis using Cox regression model revealed that only body mass index (BMI) less than 18 kg/m2 (p=0.030; hazard ratio [HR], 12.09; 95% confidence interval [CI], 1.28-114.33) and CT progression before 36 months from the diagnosis of IPF (p=0.042; HR, 13.56; 95% CI, 1.10-167.17) were independently associated with mortality among age more than 60 years, male gender, the presence of respiratory symptom at the diagnosis, initial BMI less than 18 kg/m2, initial forced vital capacity less than 70% of predicted, and disease progression on CT before 36 months.
CONCLUSION: Because low BMI at the diagnosis of IPF and progression on follow-up CT indicate shorter survival, IPF patients with low BMI and/or progression before 36 months following the diagnosis should be closely monitored.
CLINICAL IMPLICATIONS: An IPF patient, who has been stable over 36 months following the diagnosis, is likely to survive longer than usually expected. Low BMI may reflect high level of systemic inflammation associated with IPF.
DISCLOSURE: Ji-Hye Kim, No Financial Disclosure Information; No Product/Research Disclosure Information