FIGURE 3.

a) Mean heart rate during sleep for children who had normal apnoea–hypopnoea index (AHI) scores (either spontaneously or following adenotonsillectomy) versus those who still had polysomnography (PSG)-defined obstructive sleep apnoea syndrome. b) Subgroup analysis of heart rate during the follow-up PSG of children whose AHI score had normalised (AHI−) versus those whose AHI scores did not normalise (AHI+) within each arm. Data are presented as group means and standard error. eAT: early adenotonsillectomy; WWSC: watchful waiting with supportive care. *: p<0.05; **: p<0.01.