Figure 1

Predicted probability and 95% confidence intervals of bronchiolitis requiring a health care visit during infancy (hospitalization, emergency department visit, or outpatient visit) by infant age in months at the winter virus peak ( ${\chi }_3^2$= 345.52; P < 0·001). Results were obtained from a multivariable logistic regression model. Effect was adjusted for gender, infant race, birth weight, gestational age, number of living siblings, region of residence, maternal smoking, marital status, maternal education, and season. Reprinted with permission from Wu et al, Am J Respir Crit Care Med 178:1123–1129, 2008.