Maayke Hunfeld

187 Shockable rhythm and outcome Supplementary material Stratified analysis for age are presented in the supplementary material. It proved unfeasible to create a nearest-neighbor propensity matching model (for 1:1 as well as 1 to many matching) because of the age distribution of shockable compared to non-shockable rhythm. The results are therefore not presented. The child and CA characteristics sorted by age group are presented in supplementary table 1. In adolescents (aged 12-18 years) the incidence of shockable rhythm was 39%. In the analysis stratified by age group an unknown rhythm was associated with favorable outcome in children < 8 years (OR 5.6 [95% CI 3.6-8.8]) and children 8 years and above (OR 25.1 [95% CI 7.5-84.1) (supplementary table 2). Shockable rhythm was statistically significantly associated with favorable outcome in children 8 years and above (OR 22.7 [11.6-44.8). Primary and secondary outcome measures were similarly associated with overall survival (supplementary table 3). Discussion Over an 18-year period and after a median follow-up of 25 months, this retrospective single-center study of pOHCA showed a nine times higher odds of shockable rhythms surviving with long-term favorable neurologic outcome compared to non-shockable rhythm, even after adjustment for confounders. First documented rhythms were 14% shockable (in adolescents aged 12-18 years 39%), 66% non-shockable and 20% unknown. SHD after pOHCA was 39%. 81% of hospital survivors achieved long-term favorable neurologic outcome and of all included children 32% survived with favorable neurologic outcome (17, 22, 24). Only few studies have true long-term follow-up and are thus comparable with the present study. We will summarize these, beyond case reports or series (17, 22-24, 27). The study of Meert et al., a secondary analysis of The Therapeutic Hypothermia after Pediatric Cardiac Arrest Out-of-Hospital (THAPCA-OH) trial, has comparable methodology as the present study as children were included after OHCA upon admission to hospital (17). They also found that shockable rhythm was associated with greater 12-month survival and greater 12-month survival with favorable neurobehavioral functioning, assessed using the Vineland Adaptive Behavior Scales. However, there are important differences: 1. Inclusion criteria; in THAPCA children were included when unresponsive and mechanically ventilated after ROSC, creating a specific pOHCA population. 2. Furthermore; only a fraction of eligible children presenting to the hospital were included (295/1355, 22%). 3. THAPCA was a randomized trial comparing the efficacy of therapeutic hypothermia with therapeutic 6