Unadjusted model	Adjusted for patient and arrest characteristics
	Risk ratio (95% CI)	Risk ratio (95% CI)
Out of Hospital Cardiac Arrest
Calcium given	0.73 (0.64 – 0.83)	0.73 (0.59 – 0.91)
Age		1.00 (0.99 – 1.01)
Sex
Female		--
Male		1.01 (0.81 – 1.26)
Witnessed status
Unwitnessed arrest		--
Witnessed arrest		1.25 (1.00 – 1.56)
Initial cardiac rhythm
Shockable rhythm		--
Not shockable rhythm		1.05 (0.86 – 1.28)
In Hospital Cardiac Arrest
Calcium given	0.75 (0.63 – 0.91)	0.75 (0.53 – 1.08)
Age		1.00 (0.99 – 1.01)
Sex
Female		--
Male		0.98 (0.67 – 1.43)
Witnessed status
Unwitnessed arrest		--
Witnessed arrest		1.16 (0.80 – 1.70)
Initial cardiac rhythm
Shockable rhythm		--
Not shockable rhythm		1.04 (0.73 – 1.49)

Risk ratios are presented as risk of survival to hospital admission for patients receiving calcium compared to those that do not receive calcium. Risk ratios greater than 1 represent a protective association for calcium and risk ratio less than 1 represent a harmful association.