NEW YORK (Reuters) -- Women are more likely than men to develop a serious and prolonged asthma episode that requires critical care, new research suggests. However, once admitted, men are more likely to need extreme therapies, such as intubation.

The findings are based on a study of patients who were admitted to an ICU in Connecticut with a diagnosis of asthma between 1994 and 2000. Of the 53 patients identified, 37 were younger than 50 years of age and met criteria for severe, prolonged asthma, or status asthmaticus. The age requirement was set to reduce the chances of including patients with chronic obstructive pulmonary disease.

The 37 patients accounted for a total of 53 admissions during the study period. The average age of the study group was 30.8 years. With the exception of 13 black and 7 white subjects, the patients were Hispanic.

Twenty-four of the patients were female, nearly double the number of male patients -- 13 -- senior author Dr. Constantine A. Manthous, from Bridgeport Hospital in Connecticut, and colleagues note. Moreover, seven women, but only three men were admitted to the ICU more than once.

The absolute number of intubations was higher for females, but the rate of intubation was higher for males, according to the report published in the Journal of Asthma. Men were 60 percent more likely to undergo intubation than women.

Other outcomes such as the length of stay did not show a gender difference.

During the study period, women were more likely than men to visit the emergency department, which might partly explain the excess ICU admissions for status asthmaticus seen in women. Other reasons for the gender difference in admission could be because women are "less likely to respond to initial therapies" or because breathing problems tend to be more severe in women.

The reasons why men were more likely to be intubated are even less clear, the authors note. One possibility is that men are more likely to have rapid-onset asthma, a condition that could raise the odds of intubation.

"Future studies may help to illuminate mechanisms to confirm and explain these findings," the researchers conclude.