For the critical outcome of survival to 180 days with good neurologic outcome, we identified very-low-quality evidence for prognostic significance (downgraded for imprecision and risk of bias) from 1 pediatric observational prospective cohort study of IHCA and OHCA,(Fink 2014, 664-674) enrolling 43 children showing that reactive pupils at 24 hours after ROSC is associated with improved outcomes (RR, 5.94; 95% CI, 1.5–22.8). For the important outcome of survival to hospital discharge, we identified very-low-quality evidence for prognostic significance (downgraded for imprecision and risk of bias, but with a moderate-dose response) from 4 pediatric observational studies of IHCA and OHCA,(Nishisaki 2007, 10-17; Meert 2009, 544-553; Moler 2011, 141-149; Abend 2012, 32-38) enrolling a total of 513 children showing that pupils reactive to light 12 to 24 hours after ROSC is associated with improved outcomes (RR, 2.3; 95% CI, 1.8–2.9). For the important outcome of survival to hospital discharge with good neurologic outcome, we identified very-low-quality evidence for prognostic significance (downgraded for risk of bias and imprecision, but with a moderate effect size) from 2 pediatric observational studies of IHCA and OHCA,(Nishisaki 2007, 10-17; Abend 2012, 32-38) enrolling a total of 69 children showing that pupils reactive to light before hypothermia or 24 hours after ROSC is associated with improved outcomes (OR, 3.0; 95% CI, 1.4–6.5). For the important outcomes of survival to hospital discharge and hospital discharge with good neurologic outcome, we identified very-low-quality evidence for prognostic significance (downgraded for risk of bias and imprecision) from 2 pediatric observational studies of IHCA and OHCA,(Topjian 2009, 479-490; Fink 2014, 664-674) enrolling a total of 78 children showing that lower neuron-specific enolase (NSE) or S100B serum levels at 24, 48, and 72 hours are associated with an increased likelihood of improved outcomes (P