Table 2.

Relation of Collapse of Witnessed VF to Observation of Gasping

	Gasping (Yes) (n=191)
	% (n)	OR (95% CI)*
Collapse after EMS arrival (n=119)	32.8 (39)	2.7 (1.6–4.7)¶
Collapse before EMS arrival, min (n)
<7 (363)	20.1 (73)	1.00 (Ref)
7–9 (360)	13.9 (50)	0.6 (0.4–1.0)
>9 (338)	7.4 (25)	0.3 (0.2–0.5)¶
Missing data (38)†	10.5 (4)	…
Witnessed VF (n)‡
No (690)	13.6 (94)	1.00
Yes (527)	18.4 (97)	1.7 (1.2–2.4)§

^*The model was adjusted for age, gender, bystander CPR performed, location of cardiac arrest, and VF. Negelkerke R²=0.086; Cox and Snell R²=0.05. Model χ² (8) =60.55; P<0.001.

^†Thirty-eight cases were missing either collapse time or EMS arrival time and were excluded from analysis.

^‡One case excluded because of missing initial rhythm analysis.

^§P<0.01;

^¶P<0.001.