Blacks in Pennsylvania are significantly more likely than whites to die from blood clots in the lungs, according to a new study.

The study, led by researchers at the VA Pittsburgh Healthcare System, concluded that blacks with the clots, known as pulmonary embolisms, were 30 percent more likely to die than whites once the data were adjusted for other health factors that could affect mortality risk.

The findings, released early online, are being published in the December issue of the American Journal of Public Health.

Reasons for the higher death rates among blacks are unclear, but lack of access to optimum medical care may play a role, said Dr. Said Ibrahim, the study's lead author and an associate professor at the University of Pittsburgh School of Medicine.

The study relied on data obtained from the Pennsylvania Health Care Cost Containment Council for more than 14,000 patients with pulmonary embolisms who were treated in hospitals between January 2000 and November 2002. Mortality rates included patients who died within 30 days of their first admission to the hospital.

Pulmonary embolism is a common cause of death in hospitalized people who must remain in bed for a long time. The embolisms most often occur when blood clots traveling from the legs cause sudden blockages in lung arteries.