BACKGROUND The association between night/after-hours surgery and patients' mortality is unclear. METHODS The protocol of this systematic review was registered in PROSPERO (CRD42019128534). We searched Medline, PubMed, and EMBASE from inception until August 29, 2019 for studies examining an association between timing of surgical procedures (time of anaesthesia induction or surgery start) and mortality (within 30 days or in-hospital) in adult patients. Studies reporting patients' mortality after surgery performed during the weekend only were excluded. All analyses were done using the random-effects model. RESULTS We included 40 observational studies (36 retrospective and four prospective) that examined a total of 2 957 065 patients. Twenty-eight studies were judged of good quality and 12 of poor quality according to Newcastle-Ottawa score, owing to a lack of adequate comparability between study groups. Primary analysis from adjusted estimates demonstrated as association between night/after-hours surgery and a higher risk of mortality (odds ratio [OR]=1.16; 95% confidence interval [CI], 1.06-1.28; P=0.002; number of studies=18; I2=67%) based on low certainty evidence. Analysis from unadjusted estimates demonstrated a consistent association (OR=1.47; 95% CI, 1.19-1.83; P=0.0005; studies=38, I2=97%; low certainty). The number of centres per study had no credible subgroup effect on the association between the time of surgery and mortality. We were unable to evaluate the subgroup effect of urgency of surgery because of high heterogeneity. CONCLUSIONS Night/after-hours surgery may be associated with a higher risk of mortality. Patients' and surgical characteristics seem not to completely explain this finding. However, the certainty of the evidence was low.

中文翻译：

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夜间/下班后手术与死亡率之间的关联：系统评价和荟萃分析。

背景技术夜间/下班后手术与患者死亡率之间的关联尚不清楚。方法该系统评价的方案已在PROSPERO（CRD42019128534）中注册。从开始到2019年8月29日，我们对Medline，PubMed和EMBASE进行了搜索，以研究成年患者手术程序的时间（麻醉诱导或手术开始的时间）与死亡率（30天或住院之内）之间的相关性。仅报告了周末进行手术后患者死亡的研究。所有分析均使用随机效应模型进行。结果我们纳入了40项观察性研究（36项回顾性研究和4项前瞻性研究），共检查了2 957 065例患者。根据纽卡斯尔-渥太华评分，有28项研究的质量为好，其中12项质量为差，由于研究组之间缺乏足够的可比性。调整后估计数的初步分析表明，夜间/下班后手术与更高的死亡风险之间存在关联（赔率[OR] = 1.16； 95％置信区间[CI]为1.06-1.28； P = 0.002；研究次数= 18; I2 = 67％）。来自未经调整的估计值的分析显示出一致的关联性（OR = 1.47； 95％CI，1.19-1.83； P = 0.0005；研究= 38，I2 = 97％；低确定性）。每个研究的中心数量对手术时间和死亡率之间的关联没有可信的亚组影响。由于高度异质性，我们无法评估紧急手术的亚组效应。结论夜间/下班后手术可能与更高的死亡风险有关。耐心' 而且外科手术的特征似乎不能完全解释这一发现。但是，证据的确定性很低。