Objective: To distinguish between differences in prevalence, asthma severity, and treatment to explain sex-related differences in hospitalized asthma patients.
Design: Medical record review.
Setting: Thirty US hospitals as part of the University HealthSystem Consortium Asthma Clinical Benchmarking Project.
Patients: A random sample of patients aged 2 to 54 years and admitted to the hospital for acute asthma from 1999 to 2000.
Measurements: Demographics, medical history, initial oxygen saturation, initial peak expiratory flow (adults), initial pulmonary index (children), emergency department course, length of hospital stay, and discharge plans.
Results: The cohort included 606 pediatric (aged 2 to 17 years) and 680 adult (aged 18 to 54 years) inpatients. The sex ratio varied significantly by age: 40% were girls 2 to 17 years of age, and 68% were women 18 to 54 years of age p < 0.001). Among children, girls did not differ from boys according to asthma history, pulmonary index scores, or hospital length of stay. Among adults, women were more likely to have a primary care provider (90% vs 73%, p < 0.001) but did not differ according to asthma history or recent medication use. Women had a higher mean initial PEF compared to men (43% of predicted vs 36% of predicted, p < 0.001) and higher median initial oxygen saturation (95% vs 93%, p = 0.002) but did not differ by hospital length of stay. No sex differences in discharge regimens were identified in children or adults.
Conclusions: Among US inpatients with acute asthma, male children are more common than female children, while women are more common in adults. The results in children are probably explained by prevalence differences, since no sex differences were seen in markers of asthma severity or treatment. In adults, increased symptoms in response to a given level of airway obstruction in women may contribute to the female predominance in asthma hospitalizations.