Fig. 2

Data from the “Osservatorio” database: comparison between hospitalized (H⁺) and not hospitalized (H⁻) children. a On the ordinate, the number of H⁺ and H⁻ infants evaluated with a chronological age ≤12 months (mo) are shown and, on the abscissa, the three weeks’ gestational age (wGA) groups. The H⁺-to- H⁻ ratios in the three wGA groups are also included in the figure (*). b On the ordinate the percentage of H⁺ and H⁻ infants that were RSV+ or RSV- are shown and, on the abscissa, the three wGA groups. c and d. The same data in children evaluated with a chronological age >12–24 mo are shown. In the two chronological age groups, panels a and c, the tendency of the hospitalized-to-not-hospitalized ratio to progressively decrease with increasing wGA did not reach the statistically significance (p = 0.35 and p = 0.32, respectively). In the ≤12 mo group, panel b, the percentage of hospitalized infants that were also RSV⁺ was also progressively decreasing with increasing wGA, without reaching the statistically significance (p = 0.43). In the >12-24 mo, panel d, the low hospitalization numbers and hospitalized-to-not-hospitalized ratios were associated with a low RSV⁺ frequency in the <29 and 29- < 32 wGA groups, and no RSV⁺ hospitalized infants in the 32- < 35 wGA group (Fig. 2d) (p = 0.04)