During recent decades, asthma prevalence and mortality have increased rapidly worldwide among children, teenagers, and young adults. Little attention has been placed on the latter group. Therefore, we studied risk factors for intubation in young adults as potential severity markers predictive of death. We analyzed demographic data from a retrospective cohort of hospitalized asthmatic young adults, including all asthmatics aged 20-34 years admitted over a 10-year period (1984-1994) to the University of California, Davis, Medical Center, Sacramento, California. A total of 550 such asthma admissions were reviewed, involving 351 women and 199 men, mean age 27.9 +/- 4.2 years. Of this group, 180 young adults were white, 209 were black, 118 were Hispanic, 16 were Asian, and 27 were American Indian. By National Heart, Lung, and Blood Institute guidelines, there were 95 mild, 322 moderate, and 133 severe cases. Thirty-four young adults required intubation for their asthma. Significant risk factors identified for intubation were psychological factors and psychosocial problems odds ratio (OR) 25.0; 95% confidence interval (Cl) 12.4, 50.8, prior intubation (OR 23.6; 95% Cl 7.5, 42.8), language barrier (OR 17.3, 95% Cl 7.9, 38.0), prior asthma emergency room visit in past year (OR 10.2; 95% Cl 4.6, 16.0), crowding (OR 8.5; 95% Cl 4.6, 16.0), prior asthma hospitalization in past year (OR 8.3; 95% Cl 3.3, 20.8), family dysfunction (OR 7.2; 95% Cl 3.6, 14.3), active smoking/secondhand smoke exposure (OR 7.1; 95% Cl 5.1, 9.9), respiratory infection (OR 6.0; 95% Cl 3.2, 11.5), low formal education (OR 5.7; 95% Cl 2.9, 11.2), unemployment (OR 4.9; 95% Cl 2.5, 9.5), steroid dependence (OR 4.6; 95% Cl 3.2, 6.4), and atopy (OR 4.3; 95% Cl 2.1, 8.5). These variables are important determinants of baseline risk factors.