Mortality rates from pulmonary fibrosis (PF) have increased significantly in recent years, and are likely to continue rising, reports the American Journal of Respiratory and Critical Care Medicine, a publication of the American Thoracic Society.

Between 1992 and 2003, the age-adjusted mortality rate from PF—an often-fatal disease involving scarring of the lung—rose by nearly 28.4% in men, and 41.3% in women. Over the same time period, an increasing percentage of patients with PF died of the disease itself rather than of coexisting conditions.

The study, led by Amy Olsen, MD, MSPH, of the University of Colorado Health Sciences Center, analyzed the cause of death listed on death certificates for more than 28 million decedents using data compiled by the National Center for Health Statistics. The study is the first to consider sex, race, age, and ethnicity as contributing factors.

Researchers suggested that differences in the diagnosis rate between men and women might be attributable to gendered smoking patterns and their historical variations. Older white men have a consistently higher rate of mortality from PF than women, but the female rate is increasing at a faster pace. The cause of PF diagnosis and death along ethnic lines, historically higher among older whites, remained murky.

Geographical variation also seemed to influence mortality rates, but the researchers were unable to determine whether these differences represent a true variation in the incidences of death according to patient location or are simply coincidental.

Similarly, the researchers were unable to determine whether the increased percentage of patients with PF dying from the disease itself represents an improvement in treatments for commonly co-existing conditions such as cardiovascular disease, reflects diagnostic changes, or is the result of a new classification system implemented in 1997 that excludes patients with more hopeful prognoses.

"Although once considered an orphan disease, our results suggest that PF should no longer be considered a rarity," Dr. Olson concluded.