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. Author manuscript; available in PMC: 2021 Jan 21.
Published in final edited form as: Circulation. 2020 Jan 16;141(3):188–198. doi: 10.1161/CIRCULATIONAHA.119.042240

Table 3.

Unadjusted and adjusted primary and secondary study outcomes in the full study population and in patients within that population with complete covariate data (complete data sample).

Outcome (full study population) Relative risk % (95% CI) Overall p for IV/IO interaction§
Unadjusted Outcome (full study population)
Unadjusted outcome (complete data sample) 		Adjusted Outcome‡ (complete data sample)
Vascular Access*
[n in each treatment arm]† 		Placebo
n (%)		 Lidocaine
n (%)		 Amiodarone
n (%)		 Amiodarone vs Placebo Lidocaine vs Placebo Amiodarone vs Placebo Lidocaine vs Placebo
Survival to Hospital Admission (Full study population n= 3019; Complete data sample n = 2876)
IV 1070/2353 (45.5%)
[n=825, 768, 760]		 328 (39.8%) 372 (48.4%) 370 (48.7%) 1.22 (1.09, 1.37) 1.21 (1.09, 1.36) 1.23 (1.11, 1.37) 1.24 (1.11, 1.38) 0.11
1.25 (1.11, 1.40) 1.24 (1.11, 1.39)
IV/IO interaction (p) 0.15 0.85
IO 259/660 (39.2%)
[n= 228, 220, 212]		 89 (39%) 95 (43.2%) 75 (35.4%) 0.91 (0.71, 1.16) 1.11 (0.89, 1.39) 0.95 (0.75, 1.21) 1.20 (0.97, 1.49)
0.92 (0.71, 1.18) 1.15 (0.92, 1.45)
Survival to hospital discharge (Full study population n=3004; Complete data sample n=2861)
IV 554/2347 (23.6%)
[n= 824, 765, 758]		 170 (20.6%) 188 (24.6%) 196 (25.9%) 1.25 (1.05, 1.50) 1.19 (0.99, 1.43) 1.26 (1.06, 1.50) 1.21 (1.02, 1.45) 0.32
1.28 (1.06, 1.54) 1.25 (1.03, 1.50)
IV/IO interaction (p) 0.22 0.48
IO 137/657 (20.9%)
[n= 227, 218, 212]		 51 (22.5%) 45 (20.6%) 41 (19.3%) 0.86 (0.60, 1.24) 0.92 (0.64, 1.31) 0.94 (0.66, 1.32) 1.03 (0.74, 1.44)
0.88 (0.61, 1.27) 0.94 (0.66, 1.35)
Survival with mRS ≤ 3 at hospital discharge (Full study population n=2999; Complete data sample n=2857)
IV 431/2342 (18.4%)
[n= 823, 764, 755]		 137 (16.6%) 142 (18.6%) 152 (20.1%) 1.21 (0.98, 1.49) 1.12 (0.90, 1.38) 1.24 (1.02, 1.52) 1.17 (0.95, 1.44) 0.47
1.25 (1.01, 1.55) 1.17 (0.94, 1.45)
IV/IO interaction (p) 0.31 0.48
IO 97/657 (14.8%)
[n= 227, 218, 212]		 37 (16.3%) 30 (13.8%) 30 (14.2%) 0.87 (0.56, 1.36) 0.84 (0.54, 1.32) 0.94 (0.61, 1.43) 0.96 (0.63, 1.46)
0.87 (0.55, 1.36) 0.86 (0.55, 1.34)

Abbreviations: CI - confidence interval, IO - intraosseous vascular access, IV - intravenous vascular access, mRS - modified Rankin scale

Full study population refers to all patients with a known survival outcome (>99% of cases); complete data sample refers to patients in whom all covariate data were known (~95% of cases).

*

The numerator of the fractions shown in the first column corresponds to the combined number of patients in placebo, lidocaine and amiodarone groups who achieved the described endpoint, and the denominator to the total number of patients who received that (IV or IO) route of treatment.

†

The [n =] refers to the number of patients in the placebo, lidocaine and amiodarone groups, respectively, in whom data were available for the indicated endpoint.

‡

Adjusted for age, sex, cardiac cause, public location, EMS witnessed, bystander witnessed, bystander CPR, EMS arrival time, ALS arrival time, time to study drug, and study site

§

Comparing the overall interaction between IV and IO treatment for amiodarone versus placebo and lidocaine versus placebo in the adjusted outcome analysis. The corresponding p values for the overall interaction for unadjusted outcomes in the full study population and in the sample with complete data were 0.08 and 0.09 respectively for survival to hospital admission; 0.18 and 0.18 for survival to hospital discharge; and 0.29 and 0.36 for survival with mRS ≤ 3 at hospital discharge.