论文部分内容阅读
目的介绍需暴露人数(NNE)的基本概念、计算方法及用途。方法以琥珀水杨酸交联血红蛋白溶液(DCLHb)治疗急性创伤后出血性休克与患者入院后28天内死亡的研究为实例,计算粗NNE和调整NNE及相应95%可信区间(CI)。结果通过计算得到暴露DCLHb的粗NNEH=3.7(95%CI:2.2~11.5);在调整了基线死亡风险的混杂偏倚后,暴露DCLHb的调整NNEH=2.6(95%CI:1.6~8.0)。说明在试验组研究对象的基线死亡风险(病情严重程度)的分布与对照组相同的情况下,平均每2.6例创伤后出血性休克患者暴露于DCLHb就会在入院后28天内新增1例死亡。结论NNE可用来说明在前瞻性研究中,相对于非暴露组,要新增(或预防)一例某病的发病或死亡病例,需暴露于某因素的平均估计人数。作为衡量暴露因素作用强度的一个新指标,NNE可以更为直观地表达研究的结果,易被临床医生、卫生决策者及公众所接受。
Objective To introduce the basic concept, calculation method and application of NNE. Methods Acute salicylic acid cross-linked hemoglobin solution (DCLHb) was used to treat acute post-traumatic hemorrhagic shock and death within 28 days after admission. Crude NNE, adjusted NNE and corresponding 95% confidence interval (CI) were calculated. Results Crude NNEH = 3.7 (95% CI: 2.2 to 11.5) was obtained by calculation for exposing DCLHb; adjustment for exposure to DCLHb was adjusted to NNEH = 2.6 (95% CI: 1.6 to 8.0) after a miscellaneous bias adjusted for baseline risk of death. Indicating that an average of every 2.6 post-traumatic hemorrhagic shock patients exposed to DCLHb had an additional 1 death within 28 days after admission in the same baseline risk of death (severity of illness) as in the control subjects . Conclusions NNE can be used to illustrate the average number of patients to be exposed (or prevented) from developing or preventing a disease in a prospective study from being exposed to a factor relative to the non-exposed group. As a new measure of the strength of exposure, NNE can more directly express the results of the study and is easily accepted by clinicians, health policymakers, and the general public.