Objective

We sought to evaluate the utility and validity of ICU-free days and ventilator-free days as candidate outcomes for OHCA trials.

Methods

We conducted a secondary analysis of the Pragmatic Airway Resuscitation Trial. We determined ICU-free (days alive and out of ICU during the first 30 days) and ventilator-free days (days alive and without mechanical ventilation). We determined ICU-free and ventilator-free day distributions and correlations with Modified Rankin Scale (MRS). We tested associations with trial interventions (laryngeal tube (LT), endotracheal intubation (ETI)) using continuous (t-test), non-parametric (Wilcoxon Rank-Sum test - WRS), count (negative binomial - NB) and survival models (Cox proportional hazards (CPH) and competing risks regression (CRR)). We conducted bootstrapped simulations to estimate statistical power.

MAIN Results

ICU-free days was skewed; median 0 days (IQR 0, 0), survivors only 24 (18, 27). Ventilator-free days was skewed; median 0 (IQR 0, 0) days, survivors only 27 (IQR 23, 28). ICU-free and ventilator-free days correlated with MRS (Spearman’s ρ = -0.95 and −0.97). LT was associated with higher ICU-free days using t-test (p = 0.001), WRS (p = 0.003), CPH (p = 0.02) and CRR (p = 0.04), but not NB (p = 0.13). LT was associated with higher ventilator-free days using t-test (p = 0.001), WRS (p = 0.001) and CRR (p = 0.03), but not NB (p = 0.13) or CPH (p = 0.13). Simulations suggested that t-test and WRS would have had the greatest power to detect the observed ICU- and ventilator-free days differences.

Conclusion

ICU-free and ventilator-free days correlated with MRS and differentiated trial interventions. ICU-free and ventilator-free days may have utility in the design of OHCA trials.

中文翻译：

---

评估无重症监护病房和无呼吸机天数作为实用气道复苏试验中的替代结果

客观的

我们试图评估无 ICU 天数和无呼吸机天数作为 OHCA 试验候选结果的效用和有效性。

方法

我们对实用气道复苏试验进行了二次分析。我们确定了无 ICU 天数（前 30 天内存活和离开 ICU 的天数）和无呼吸机天数（存活天数并且没有机械通气）。我们确定了无 ICU 和无呼吸机的天数分布以及与改良 Rankin 量表(MRS) 的相关性。我们使用连续（t 检验）、非参数（Wilcoxon 秩和检验 - WRS）、计数（负二项式 - NB）和生存模型测试了与试验干预（喉管 (LT)、气管插管 (ETI)）的关联（Cox 比例风险（CPH）和竞争风险回归（CRR））。我们进行了自举模拟来估计统计功效。

主要结果

无 ICU 天数出现偏差；中位数 0 天 (IQR 0, 0)，幸存者只有 24 (18, 27)。无呼吸机天数出现偏差；中位数 0 (IQR 0, 0) 天，幸存者只有 27 (IQR 23, 28)。无 ICU 和无呼吸机天数与 MRS 相关（Spearman 的 ρ = -0.95 和 -0.97）。使用 t 检验 (p = 0.001)、WRS (p = 0.003)、CPH (p = 0.02) 和 CRR (p = 0.04)，LT 与更高的无 ICU 天数相关，但与 NB (p = 0.13) 无关。使用 t 检验 (p = 0.001)、WRS (p = 0.001) 和 CRR (p = 0.03)，LT 与较高的无呼吸机天数相关，但与 NB (p = 0.13) 或 CPH (p = 0.13) 无关。模拟表明，t 检验和 WRS 将具有最大的能力来检测观察到的 ICU 和无呼吸机天数差异。

结论

无 ICU 和无呼吸机天数与 MRS 和差异化试验干预相关。无 ICU 和无呼吸机天数可能对 OHCA 试验的设计有用。