Departments of Neurosurgery and.
J Neurosurg. 2014 Mar;120(3):605-11. doi: 10.3171/2013.9.JNS13640. Epub 2013 Oct 4.
Increasing evidence exists that treatment of complex medical conditions in high-volume centers is found to improve outcome. Patients with subarachnoid hemorrhage (SAH), a complex disease, probably also benefit from treatment at a high-volume center. The authors aimed to determine, based on published literature, whether a higher hospital caseload is associated with improved outcomes of patients undergoing treatment after aneurysmal subarachnoid hemorrhage.
The authors identified studies from MEDLINE, Embase, and the Cochrane Library up to September 28, 2012, that evaluated outcome in high-volume versus low-volume centers in patients with SAH who were treated by either clipping or endovascular coiling. No language restrictions were set. The compared outcome measure was in-hospital mortality. Mortality in studies was pooled in a random effects meta-analysis. Study quality was reported according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria.
Four articles were included in this analysis, representing 36,600 patients. The quality of studies was graded low in 3 and very low in 1. Meta-analysis using a random effects model showed a decrease in hospital mortality (OR 0.77 [95% CI 0.60-0.97]; p = 0.00; I(2) = 91%) in high-volume hospitals treating SAH patients. Sensitivity analysis revealed the relative weight of the 1 low-quality study. Removal of the study with very low quality increased the effect size of the meta-analysis to an OR of 0.68 (95% CI 0.56-0.84; p = 0.00; I(2) = 86%). The definition of hospital volume differed among studies. Cutoffs and dichotomizations were used as well as division in quartiles. In 1 study, low volume was defined as 9 or fewer patients yearly, whereas in another it was defined as fewer than 30 patients yearly. Similarly, 1 study defined high volume as more than 20 patients annually, and another defined it as more than 50 patients a year. For comparability between studies, recalculation was done with dichotomized data if available. Cross et al., 2003 (low volume ≤ 18, high volume ≥ 19) and Johnston, 2000 (low volume ≤ 31, high volume ≥ 32) provided core data for recalculation. The overall results of this analysis revealed an OR of 0.85 (95% CI 0.72-0.99; p = 0.00; I(2) = 87%).
Despite the shortcomings of this study, the mortality rate was lower in hospitals with a larger caseload. Limitations of the meta-analysis are the not uniform cutoff values and uncertainty about case mix.
越来越多的证据表明，在高容量中心治疗复杂的医疗状况可改善治疗效果。蛛网膜下腔出血（SAH）患者的病情较为复杂，可能也能从高容量中心的治疗中受益。作者旨在根据已发表的文献确定，在接受治疗的动脉瘤性蛛网膜下腔出血患者中，医院的手术量是否与治疗结果的改善相关。
作者从 MEDLINE、Embase 和 Cochrane 图书馆中检索了截至 2012 年 9 月 28 日的研究，评估了在接受夹闭或血管内栓塞治疗的 SAH 患者中，高容量中心与低容量中心的治疗效果。未设置语言限制。比较的结果衡量标准是住院死亡率。使用随机效应荟萃分析对研究中的死亡率进行了汇总。根据 GRADE（推荐评估、制定与评价）标准报告研究质量。
该分析纳入了 4 篇文章，共 36600 名患者。3 项研究的质量被评为低质量，1 项研究的质量被评为极低质量。使用随机效应模型的荟萃分析显示，高容量医院治疗 SAH 患者的住院死亡率降低（OR 0.77 [95% CI 0.60-0.97]；p=0.00；I²=91%）。敏感性分析揭示了 1 项低质量研究的相对权重。去除质量非常低的研究后，荟萃分析的效应量增加至 OR 0.68（95% CI 0.56-0.84；p=0.00；I²=86%）。研究中对医院手术量的定义不同。使用了截断值和二分法，以及四分位数的划分。在 1 项研究中，低容量定义为每年 9 例或以下，而在另一项研究中，低容量定义为每年 30 例以下。同样，在 1 项研究中，高容量定义为每年 20 例以上，而另一项研究则定义为每年 50 例以上。为了使研究之间具有可比性，如果有二分数据，则进行重新计算。如果有可用的核心数据，则重新计算 Cross 等人 2003 年的研究（低容量≤18，高容量≥19）和 Johnston 等人 2000 年的研究（低容量≤31，高容量≥32）。这项分析的总体结果显示，OR 为 0.85（95% CI 0.72-0.99；p=0.00；I²=87%）。
尽管这项研究存在缺陷，但手术量较大的医院的死亡率较低。荟萃分析的局限性在于不统一的截断值和对病例组合的不确定性。
