Globally, out-of-hospital cardiac arrest (OHCA) is one of the leading causes of mortality [1]. Annually, >356,000 patients experience OHCA in the United States [2]. Although the survival rates of patients with OHCA have increased over the decades, they remain low [[3], [4], [5]].

The sex-related differences in survival outcomes in patients with OHCA remain controversial. Some studies have reported that women have better survival outcomes than men [6,7], while others have reported worse outcomes than men [8,9] or no differences [[10], [11], [12], [13], [14], [15], [16], [17], [18]]. Controversial results for sex-related differences also have been reported for neurological outcomes in patients with OHCA [6,7,10,12,16,[18], [19], [20], [21], [22]]. However, most previous studies only adjusted for prehospital variables and not for in-hospital management [[6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16],[19], [20], [21]]. Recently, our group reported sex disparities in OHCA in-hospital management [23]. As in-hospital management significantly affects patient survival outcomes, adjustment for sex-based in-hospital management disparities is necessary to appropriately evaluate sex-related differences in OHCA survival outcomes.

Several previous studies that reported no sex-related difference in survival outcomes revealed better survival outcomes in women than men in specific age groups [13,14,16]. A recent study reported that young women with OHCA had better neurological outcomes than men, while older women had worse neurological outcomes than men [24]. Thus, age needs to be considered to better understand the differences in survival outcomes in patients with OHCA.

To address these issues, we aimed to investigate sex-related differences in survival outcomes in patients with OHCA after adjustment for sex-based in-hospital management disparities. Further, we evaluated the effect of age on the differences in survival outcomes between sexes in patients with OHCA.