Mortality of patients by subgroup with constant illness severity.

The mortality of patients in each subgroup with constant APACHEII score is shown with p-value using Fisher's exact test. Mortality odds ratio is the comparison subgroup versus the High subgroup.采用费希尔精确检验（Fisher's exact test）计算并给出P值，呈现了急性生理学与慢性健康状况评分系统II（APACHEII）评分固定的各亚组患者的死亡率；本研究中的死亡率比值比（mortality odds ratio），为对照亚组与高亚组之间的比值比。