Sex differences in out-of-hospital cardiac arrest across age groups

Sex differences in out-of-hospital cardiac arrest (OHCA) have been studied in adults but remain poorly explored in younger populations. We aimed to assess sex differences in OHCA across age groups to provide a comprehensive overview.

All OHCA occurring between May 2011 and December 2018 in Paris and its suburbs were analysed. Primary outcomes included sex differences in OHCA characteristics and survival to hospital discharge across three age groups: paediatric patients (28 days-18years), young adults (18-35 years) and older adults (≥35 years). Secondary outcomes included aetiology and 1-month survival. Logistic regression was used to identify factors associated with OHCA in females versus males.

Among 18 767 OHCA cases, 6185 (33.0%) were females, 360 (1.92%) were paediatric patients, 1240 (6.61%) young adults and 17 167 (91.5%) older adults.In paediatric patient, male were older (6.00 vs 2.78 years, p=0.029) and had shorter no-flow times (5.00 vs 10.0 min, p=0.007). Among young adults, OHCA in males occurred more often in public areas (61.9% vs 35.3%, p<0.001) and during sport (6.47% vs 1.53%, p<0.001); females had shorter no-flow time (3.00 vs 5.00 min, p=0.035). In older adults, males were younger (64.3 vs 71.8 years, p<0.001), more shocked (40.2% vs 23.7%, p<0.001) and more commonly managed with amiodarone (16.5% vs 8.11%, p<0.001). OHCA in males occurred more often in public areas (33.9% vs 19.8%, p<0.001) and during sport (1.94% vs 0.30%, p<0.001).After adjustment, females underwent coronary angiography less often (OR (95% CI) 0.54 (0.46 to 0.64)). Survival to hospital discharge was lower in females across all age groups, reaching statistical significance in older adults (6.23% vs 9.37%, p<0.001).

Sex differences in OHCA characteristics and outcomes were observed across all age groups and became more pronounced with increasing age, consistently indicating a better prognosis for males.