Figure 1. RHI and Age Groups.
RHI data by age groups 6–9 yrs (n=41), 10–14 yrs (n=37), and 15–19 yrs (n=35) had median (interquartile range (IQR)) of 1.19(0.29), 1.26(0.43), and 1.48(0.76), respectively. P-value for Kruskal-Wallis one-way ANOVA on ranks across age categories is P=0.001. P-values between age categories are displayed using Mann-Whitney rank sum test. Ages 6–9 vs. 15–19 yrs are significant different with respect to median RHI (P<0.0001). Ages 10–14 vs. 15–19 yrs are also significant different (P=0.002). Ages 6–9 and 10–14 yrs are not significant different (P=0.058).