The gender gap in cystic fibrosis survival.

Females with cystic fibrosis have significantly higher mortality than males from age 1 to age 20, resulting in an approximate four-year difference in median survival age. Survival is associated with a lack of colonization by pathogenic bacteria, as well as better pulmonary function, weight for height, and fitness. This statistically significant gender gap has been observed for decades and, therefore, is not likely to be the result of differential response to one of the newer treatments for cystic fibrosis.