Table 3 Baseline imbalances in time strata
From: Risk of selection bias assessment in the NINDS rt-PA stroke study
Time Stratum | Baseline Differences (% Placebo vs. % Alteplase) or (Placebo Mean vs. Alteplase Mean) | Allocation Imbalance (Δ) | Effect Size for a Modified Rankin Scale Score of 0-1 |
|---|---|---|---|
0-90 Min (N = 302) | None | Alteplase > Placebo (12) | Risk Ratio: 1.4 (1.0 – 1.9) |
Odds Ratio: 1.7 (1.0-2.6) | |||
91-180 Min (N = 322) | Aspirin (24% vs. 41%, p = .002) | Placebo > Alteplase (12) | Risk Ratio: 1.8 (1.3-2.4) |
Hyperintense Artery Sign (20% vs. 8%, p = .004) | |||
NIHSS Baseline (15.4 ± 6.9 vs. 13.5 ± 7.6, p = .021) | Odd’s Ratio: 2.4 (1.5 – 3.7) | ||
Small Vessel Ischemic Stroke (11% vs. 19%, p = .045) |