几个难点？

While impaired recovery in critically ill patients has been well described, much less is known about the impact of nutrition interventions on recovery. Of note, a recent large posthoc analysis of observational data evaluated 16 489 patients to determine associations between protein intake and in-hospital mortality and alive hospital discharge using an advanced cox regression model based on simulated feeding strategies. This posthoc reported that late (days 5–11) standard protein intake (0.8–1.2 g/kg/day) was associated with a lower hazard of in-hospital mortality (minimum 0.75 (95% confidence interval [CI] 0.64– 0.87)) and a higher hazard of alive hospital discharge (maximum HR 1.98 (95% CI 1.72–2.28)) when compared to a low protein diet, while an earlier (days 1– 11) standard or high protein intake was not associated with further improvement in outcome.Although a number of noninterventional studies report conflicting impacts of augmented protein on outcomes, few randomized controlled trials (RCTs) have been conducted. This lack of RCTs has been demonstrated in a systematic review of studies delivering enteral protein to meeting international guideline recommendations compared to usual care which revealed that only one of six identified RCTs included a measure of muscle mass or strength [15 &], which has been replicated in a more recent systematic review.

虽已充分描述重症患者的康复受损，但营养干预对康复的影响知之甚少。值得注意的是，最近一项对观察性数据的大型（16489例患者）事后分析，使用基于模拟喂养策略的高级cox回归模型来确定蛋白质摄入与住院死亡率和存活出院间的相关性。该事后研究报告显示，与低蛋白饮食相比，晚期（第5-11天）标准蛋白质摄入（0.8-1.2 g/kg/天）与住院死亡风险（最小值0.75（95%置信区间[CI]0.64-0.87））降低和存活出院机会（最大值HR 1.98（95%CI 1.72-2.28））升高相关，而早期（第1-11天）标准或高蛋白摄入与预后的进一步改善无关。虽有许多强化蛋白对预后相互矛盾影响的非干预性研究，但缺乏随机对照研究（RCT）。在一项对按国际指南建议提供肠道蛋白与常规治疗相比的系统回顾研究，已经证明了这种RCT的缺乏，该回顾研究显示，在确定的六项RCT中，只有一项RCT包括对肌肉质量或力量的测量，这在最近的系统回顾中也是如此。

1.muscle mass or strength也算是outcome？

2.which指代systematic review吗？

3.lack of RCTs，但是后面说有six identified RCTs？前面说“缺乏”，后面有“六个”是否矛盾，但又说only one of six，是不是这里只有一个，所以说缺乏，因为只有这个算是outcome