TABLE 1.

Description of Study Population

<3 Months3–11 MonthsOverall
Sample size733610 06117 397
Mean age, mo (SD)1.37 (0.55)5.84 (2.47)3.96 (2.92)
Male, %585959
APR-DRG severity level, %
    Mild646464
    Moderate293029
    Severe767
Hospital stay
    Mean LOS (SD)3.14 (2.55)*2.84 (2.50)2.97 (2.52)
    Readmission rate, %1.7*1.21.3
    Month, %
        December to February61*5860
        March to September293029
        October to November10*1211
Diagnostic testing, %
    Chest radiograph727272
    RSV61*5960
    Blood culture41*3236
    CSF culture11*15
    Nasopharyngeal culture (bacterial)9*46
    Urine culture25*1217
Medications, %
    Any antibiotics40*5045
    Parenteral antibiotics29*2828
    Oral antibiotics13*2822
    β2-agonist bronchodilators50*6157
    Racemic epinephrine242424
    Inhaled steroids2*86
    Systemic steroids11*3525
  • RSV indicates respiratory syncytial virus; CSF, cerebrospinal fluid.

  • * Differences between groups are statistically significant (P < .05).