Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
J Neurosurg. 2013 Mar;118(3):687-93. doi: 10.3171/2012.10.JNS12682. Epub 2012 Dec 14.
A positive correlation between outcomes and the volume of patients seen by a provider has been supported by numerous studies. Volume-outcome relationships (VORs) have been well documented in the setting of both neurosurgery and trauma care and have shaped regionalization policies to optimize patient outcomes. Several authors have also investigated the correlation between patient volume and cost of care, known as the volume-cost relationship (VCR), with mixed results. The purpose of the present study was to investigate VORs and VCRs in the treatment of common intracranial injuries by testing the hypotheses that outcomes suffer at small-volume centers and costs rise at large-volume centers.
The authors performed a cross-sectional cohort study of patients with neurological trauma using the 2006 Nationwide Inpatient Sample, the largest nationally representative all-payer data set. Patients were identified using ICD-9 codes for subdural, subarachnoid, and extradural hemorrhage following injury. Transfers were excluded from the study. In the primary analysis the association between a facility's neurotrauma patient volume and patient survival was tested. Secondary analyses focused on the relationships between patient volume and discharge status as well as between patient volume and cost. Analyses were performed using logistic regression.
In-hospital mortality in the overall cohort was 9.9%. In-hospital mortality was 14.9% in the group with the smallest volume of patients, that is, fewer than 6 cases annually. At facilities treating 6-11, 12-23, 24-59, and 60+ patients annually, mortality was 8.0%, 8.3%, 9.5%, and 10.0%, respectively. For these groups there was a significantly reduced risk of in-hospital mortality as compared with the group with fewer than 6 annual patients; the adjusted ORs (and corresponding 95% CIs) were 0.45 (0.29-0.68), 0.56 (0.38-0.81), 0.63 (0.44-0.90), and 0.59 (0.41-0.87), respectively. For these same groups (once again using < 6 cases/year as the reference), there were no statistically significant differences in either estimated actual cost or duration of hospital stay.
A VOR exists in the treatment of neurotrauma, and a meaningful threshold for significantly improved mortality is 6 cases per year. Emergency and interfacility transport policies based on this threshold might improve national outcomes. Cost of care does not differ significantly with patient volume.
大量研究证实，医疗服务提供者的接诊量与患者结局之间呈正相关。神经外科和创伤护理领域已有充分的文献记录了这种量效关系（volume-outcome relationship，VOR），并由此制定了区域化政策，以优化患者结局。一些作者还研究了患者接诊量与医疗成本之间的相关性，即所谓的量本关系（volume-cost relationship，VCR），但结果不一。本研究旨在通过检验以下假设来探讨常见颅内损伤治疗中的 VOR 和 VCR：小容量中心的结局较差，大容量中心的成本增加。
本研究使用 2006 年全国住院患者样本（全国最大的所有支付者数据集合），对神经创伤患者进行了横断面队列研究。使用 ICD-9 编码识别损伤后硬膜下、蛛网膜下和硬膜外出血的患者。本研究排除了转院患者。在主要分析中，检验了医疗机构神经创伤患者接诊量与患者存活率之间的关联。二次分析集中于患者接诊量与出院状态以及患者接诊量与成本之间的关系。使用逻辑回归进行分析。
总体队列的院内死亡率为 9.9%。接诊量最少（每年少于 6 例）的患者组的院内死亡率为 14.9%。每年接诊 6-11、12-23、24-59 和 60 例以上的患者组的死亡率分别为 8.0%、8.3%、9.5%和 10.0%。与每年接诊量少于 6 例的患者组相比，这些组的院内死亡率显著降低；校正后的比值比（和相应的 95%置信区间）分别为 0.45（0.29-0.68）、0.56（0.38-0.81）、0.63（0.44-0.90）和 0.59（0.41-0.87）。对于这些相同的组（再次将每年<6 例作为参考），实际成本或住院时间的估计值没有统计学差异。
神经创伤治疗中存在 VOR，显著改善死亡率的有意义阈值为每年 6 例。基于这一阈值的急诊和院际转运政策可能会改善全国的结局。医疗成本与患者接诊量无显著差异。
