Recent Advances in the Epidemiology of Pulmonary Fibrosis

Following is a summary of my presentation given at the Interstitial and Diffuse Lung Disease NetWork Open Meeting at CHEST 2010. To view the slide presentation, please visit www.chestnet.org/accp/presentations/network-special-presentations-chest-2010.

Prior epidemiologic investigations of idiopathic pulmonary fibrosis (IPF) have been limited due to its relative rarity. However, the evaluation of death certificate data provides an opportunity to investigate pulmonary fibrosis (PF) from an epidemiologic perspective in order to identify trends in disease-associated mortality and to better understand the burden of disease. Using data from the US Multiple Cause-of-Death Mortality Database (Centers for Disease Control and Prevention, National Center for Health Statistics, www.cdc.gov/nchs), our group recently reported that mortality rates from PF have significantly increased from 1992 to 2003 in both men (28.4%) and women (41.3%), and are predicted to continue to rise into the future (Olson et al. Am J Respir Crit Care Med. 2007;176[3]:277). Our results parallel the data from other recent epidemiologic investigations that indicate the incidence of disease is also increasing (Coultas et al. Am J Respir Crit Care Med. 1994;150[4]:967; Rhagu et al. Am J Respir Crit Care Med. 2006;174[7]:810; Gribbin et al. Thorax. 2006;61[11]:980). At the same time, more patients are dying of the disease itself rather than from comorbid conditions (Olson et al. Am J Respir Crit Care Med. 2007;176[3]: 277; Mannino et al. Am J Respir Crit Care Med. 1996;153[5]:1548; Panos et al. Am J Med. 1990;88[4]:396; Martinez et al. Ann Intern Med. 2005;142:963). Further, mortality rates from PF, like chronic obstructive lung disease, exhibit significant seasonal variation with a significantly higher number of deaths in the winter (17.1%, P less than .0001), followed by spring (12.7%, P less than .0001) when compared with summer months, even in the absence of recognized infection (Olson et al. Chest. 2009;136[1]:16). These results do not appear to be limited to idiopathic disease, as the prevalence of interstitial lung disease in decedents with rheumatoid arthritis has also increased over time despite an overall decline in RA-associated mortality (Olson et al. Am J Respir Crit Care Med. 2010; Sep 17 [Epub ahead of print]). Overall, these trends may represent an increase in the clinical recognition of interstitial lung disease, or perhaps they reflect the lack of effective therapies for lung fibrosis. Regardless of cause, these recent epidemiologic investigations do reveal a rapidly growing problem that deserves further research into the mechanisms of and potential therapies for lung fibrosis.

Dr. Amy Olson
NetWork Member