Prada Sergio I, Salkever David, MacKenzie Ellen J
PROESA & Department of Economics, Universidad ICESI, Calle 18 No. 122-135, Office B-102, Cali, Colombia.
Department of Public Policy, University of Maryland, Baltimore County (UMBC), Public Policy Bldg. Rm. 418, 1000 Hilltop Circle, Baltimore, MD 21250, United States.
Injury. 2014 Sep;45(9):1465-9. doi: 10.1016/j.injury.2014.02.025. Epub 2014 Feb 27.
Previous research found a positive effect of Level-I trauma centres on return to work outcomes for patients 18-64 years old who were mainly working before injury. Trauma centres were compared to hospitals that differed on average in characteristics such as size and staffing, among others. Thus, a portion of the effect found could be due to general differences in hospital variables rather than the special characteristics of Level I trauma centres. Comparing Level I trauma centres to other Teaching hospitals provides a more refined test of the effect of these centres on return-to-work outcomes.
The National Study on the Costs and Outcomes of Trauma (NSCOT) is the main source of data for our empirical investigation. We used non-linear instrumental variables methods to control for unobserved characteristics and restrict the sample to teaching hospitals. The first method is the two-stage residual inclusion model in which we identify the effect using the proportion of resident population served by Helicopter Ambulance Services (at the state level) as an instrumental variable. The second method is a recursive bivariate probit model.
We found that treatment at Level-I trauma centres has a positive effect on return to work outcomes three months after injury. The estimated effect is statistically significant and positive, but lower than the estimate that did not focus on teaching hospitals.
A previous study found positive effects of treatment at a Level-I trauma centre on return-to-work outcomes, however, a portion of the effect found was due to general differences in hospital variables.
先前的研究发现，一级创伤中心对18 - 64岁受伤前主要在工作的患者的重返工作岗位结局有积极影响。创伤中心与在规模和人员配备等特征方面平均存在差异的医院进行了比较。因此，所发现的部分影响可能归因于医院变量的一般差异，而非一级创伤中心的特殊特征。将一级创伤中心与其他教学医院进行比较，能更精确地检验这些中心对重返工作岗位结局的影响。
创伤成本与结局国家研究（NSCOT）是我们实证研究的主要数据来源。我们使用非线性工具变量方法来控制未观察到的特征，并将样本限制在教学医院。第一种方法是两阶段残差纳入模型，我们使用直升机救护服务所服务的常住人口比例（在州层面）作为工具变量来确定影响。第二种方法是递归双变量概率模型。
我们发现，在一级创伤中心接受治疗对受伤三个月后的重返工作岗位结局有积极影响。估计的影响在统计上显著且为正，但低于未关注教学医院的估计值。
先前的一项研究发现，在一级创伤中心接受治疗对重返工作岗位结局有积极影响，然而，所发现的部分影响归因于医院变量的一般差异。
