Gender differences in hospitalization rates for respiratory tract infections in Danish youth.

Overall morbidity and mortality rates in childhood are reported to be higher in males than females. As respiratory tract infections constitute the leading cause of childhood hospitalization, we examined the gender difference in rates of hospitalization due to respiratory tract infections in Danish youth (under age 25). We studied a total of 64,049 hospitalizations for otitis media, pneumonia, influenza, and other acute respiratory tract infections from 1995 to 1999, with calculation of hospitalization rates by age and gender. The male-female hospitalization rate ratio (HRR) for admission due to a respiratory tract infection decreased from 1.45 (95% confidence interval (CI) 1.42-1.48) in the age group 0 - < 5 y, to 1.62 (95% CI 1.55-1.70) in the age group 5 - < 10 y, 1.13 (95% CI 1.04-1.22) in the age group 10 - < 15 y, 0.83 (95% CI 0.76-0.90) in the age group 15 - < 20 y, and 0.87 (95% CI 0.80-0.95) in the age group 20 - < 25 y. In young children, boys were hospitalized more often than girls, but the reverse applied in children and adolescents 15-25 y of age. The study generates the hypothesis that gender plays a role in the susceptibility for respiratory infections in early childhood.