Hukkelhoven Chantal W P M, Steyerberg Ewout W, Rampen Anneke J J, Farace Elana, Habbema J Dik F, Marshall Lawrence F, Murray Gordon D, Maas Andrew I R
Center for Clinical Decision Sciences, Department of Public Health, Erasmus Medical Center, Rotterdam, The Netherlands.
J Neurosurg. 2003 Oct;99(4):666-73. doi: 10.3171/jns.2003.99.4.0666.
Increasing age is associated with poorer outcome in patients with closed traumatic brain injury (TBI). It is uncertain whether critical age thresholds exist, however, and the strength of the association has yet to be investigated across large series. The authors studied the shape and strength of the relationship between age and outcome, that is, the 6-month mortality rate and unfavorable outcome based on the Glasgow Outcome Scale.
The shape of the association was examined in four prospective series with individual patient data (2664 cases). All patients had a closed TBI and were of adult age (96% < 65 years of age). The strength of the association was investigated in a metaanalysis of the aforementioned individual patient data (2664 cases) and aggregate data (2948 cases) from TBI studies published between 1980 and 2001 (total 5612 cases). Analyses were performed with univariable and multivariable logistic regression. Proportions of mortality and unfavorable outcome increased with age: 21 and 39%, respectively, for patients younger than 35 years and 52 and 74%, respectively, for patients older than 55 years. The association between age and both mortality and unfavorable outcome was continuous and could be adequately described by a linear term and expressed even better statistically by a linear and a quadratic term. The use of age thresholds (best fitting threshold 39 years) in the analysis resulted in a considerable loss of information. The strength of the association, expressed as an odds ratio per 10 years of age, was 1.47 (95% confidence interval [CI] 1.34-1.63) for death and 1.49 (95% CI 1.43-1.56) for unfavorable outcome in univariable analyses, and 1.39 (95% CI 1.3-1.5) and 1.46 (95% CI 1.36-1.56), respectively, in multivariable analyses. Thus, the odds for a poor outcome increased by 40 to 50% per 10 years of age.
An older age is continuously associated with a worsening outcome after TBI; hence, it is disadvantageous to define the effect of age on outcome in a discrete manner when we aim to estimate prognosis or adjust for confounding variables.
在闭合性创伤性脑损伤（TBI）患者中，年龄增长与预后较差相关。然而，尚不确定是否存在关键年龄阈值，而且这种关联的强度尚未在大量病例系列中进行研究。作者研究了年龄与预后之间关系的形式和强度，即基于格拉斯哥预后量表的6个月死亡率和不良预后。
在四个具有个体患者数据的前瞻性系列研究（2664例）中检验了这种关联的形式。所有患者均为闭合性TBI且为成年患者（96%年龄<65岁）。在对上述个体患者数据（2664例）以及1980年至2001年发表的TBI研究中的汇总数据（2948例）进行的荟萃分析中（共5612例），研究了这种关联的强度。采用单变量和多变量逻辑回归进行分析。死亡率和不良预后的比例随年龄增加：35岁以下患者分别为21%和39%，55岁以上患者分别为52%和74%。年龄与死亡率和不良预后之间的关联是连续的，可用线性项充分描述，在统计学上用线性项和二次项表示效果更好。在分析中使用年龄阈值（最佳拟合阈值为39岁）会导致大量信息丢失。在单变量分析中，以每10岁的比值比表示的关联强度，死亡为1.47（95%置信区间[CI]1.34 - 1.63），不良预后为1.49（95%CI 1.43 - 1.56）；在多变量分析中分别为1.39（95%CI 1.3 - 1.5）和1.46（95%CI 1.36 - 1.56）。因此，每10岁年龄，不良预后的几率增加40%至50%。
年龄较大与TBI后的预后恶化持续相关；因此，当我们旨在估计预后或调整混杂变量时，以离散方式定义年龄对预后的影响是不利的。
