Unconditional logistic regression analyses of a physician in the ambulance car and outcome among patients with OHCA.

OR: odds ratio; CI: confidence interval.
a: Cases for which both an emergency life-saving technician (ELST) and a physician (MD) were in the ambulance car were excluded.
b: Advanced life support.
c: Selected variables included age, sex, bystander eyewitness, relationship of bystander to patient, bystander chest compression, bystander rescue breathing, use of public-access AED by bystander, first documented rhythm, and time from call to arrival at the scene for a model with ROSC as a dependent variable. As for other models, ROSC and the above selected variables were adjusted.
d: All covariates included all variables except for endpoint variables listed in Table 1 plus 46 dummy variables for the 47 prefectures in Japan for a model with ROSC as a dependent variable. As for other models, ROSC, all variables except for endpoint variables listed in Table 1, and 46 dummy variables for the 47 prefectures in Japan were adjusted.