This study evaluated the effects of age, gender, and response time on the patient outcome following out-of-hospital cardiac arrest (OHCA).
We analyzed Utstein-based registry OHCA data from Pan-Asian Resuscitation Outcomes Study (PAROS) from 2009 to 2012. The eligible patients were adult, aged ≧18 years, with non-traumatic causes who underwent resuscitation attempts. Patients without complete data, witnessed by emergency medical technicians, or with response time longer than 60 minutes were excluded. The exposures were different response times. Patients were classified into 4 subgroups for analysis: young male (< 65 years old), elder male (≥ 65 years old), young female (< 65 years old), and elder female (≥ 65 years old). The outcome of interest was survival to discharge.
During the study period, there were a total of 66,780 patients in PAROS database and 50,276 patients were finally enrolled. Increased response time was found to be negatively associated with survival rates (adjusted odds ratio [aOR] 0.93, 95% confidence interval [CI] 0.91 – 0.94), indicated the decrease of survival chance by 7% per minutes. The trend remained robust across countries. In the subgroup analysis, the young male group had the highest crude survival rate, followed by young female, elder male, and elder female (Figure 1). However, after adjusted by witnessed status, shockable rhythm, bystander cardiopulmonary resuscitation, and prehospital advanced life support, the young female became the top survival group followed by young male, elder male and elder female (Figure 2). The effect remained steady throughout all intervals of response time.
The chance of OHCA survival to discharge decreased 7% by per minute increase of response time in Asia. Although young male after OHCA appeared to have the highest survival rates, young female might have better chances of survival compared to young male if received the same prehospital attention and intervention.