Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
San Francisco Veterans Affairs Medical Center, San Francisco, California, USA.
J Neurotrauma. 2022 Nov;39(21-22):1518-1523. doi: 10.1089/neu.2022.0107. Epub 2022 Jun 15.
The association between traumatic brain injury (TBI) and risk for Alzheimer disease and related dementias (ADRD) has been investigated in multiple studies, yet reported effect sizes have varied widely. Large differences in comorbid and demographic characteristics between individuals with and without TBI could result in spurious associations between TBI and poor outcomes, even when control for confounding is attempted. Yet, inadvertent control for post-TBI exposures (e.g., psychological and physical trauma) could result in an underestimate of the effect of TBI. Choice of the unexposed or comparison group is critical to estimating total associated risk. The objective of this study was to highlight how selection of the comparison group impacts estimates of the effect of TBI on risk for ADRD. Using data on Veterans aged ≥55 years obtained from the Veterans Health Administration (VA) for years 1999-2019, we compared risk of ADRD between Veterans with incident TBI ( = 9440) and (1) the general population of Veterans who receive care at the VA (All VA) ( = 119,003); (2) Veterans who received care at a VA emergency department (VA ED) ( = 111,342); and (3) Veterans who received care at a VA ED for non-TBI trauma (VA ED NTT) ( = 65,710). In inverse probability of treatment weighted models, TBI was associated with increased risk of ADRD compared with All VA (hazard ratio [HR] 1.94; 95% confidence interval [CI] 1.84, 2.04), VA ED (HR 1.42; 95% CI 1.35, 1.50), and VA ED NTT (HR 1.12; 95% CI 1.06, 1.18). The estimated effect of TBI on incident ADRD was strongly impacted by choice of the comparison group.
创伤性脑损伤（TBI）与阿尔茨海默病和相关痴呆症（ADRD）风险之间的关联已在多项研究中进行了探讨，但报告的效应大小差异很大。TBI 患者和无 TBI 患者的合并症和人口统计学特征存在很大差异，即使尝试进行混杂因素控制，也可能导致 TBI 与不良结局之间存在虚假关联。然而，对 TBI 后暴露（例如心理和身体创伤）的无意中控制可能会低估 TBI 的影响。未暴露或对照组的选择对于估计总相关风险至关重要。本研究的目的是强调选择对照组如何影响 TBI 对 ADRD 风险的影响的估计。使用 1999 年至 2019 年期间退伍军人健康管理局（VA）获取的年龄≥55 岁退伍军人的数据，我们比较了有 TBI 事件的退伍军人（ = 9440）与以下人群患 ADRD 的风险：（1）在 VA 接受治疗的退伍军人的总体人群（所有 VA）（ = 119003）；（2）在 VA 急诊部（VA ED）接受治疗的退伍军人（ = 111342）；和（3）在 VA ED 因非 TBI 创伤接受治疗的退伍军人（VA ED NTT）（ = 65710）。在逆概率治疗加权模型中，与所有 VA（风险比 [HR] 1.94；95%置信区间 [CI] 1.84，2.04）、VA ED（HR 1.42；95% CI 1.35，1.50）和 VA ED NTT（HR 1.12；95% CI 1.06，1.18）相比，TBI 与 ADRD 风险增加相关。TBI 对新发 ADRD 的影响因对照组的选择而受到强烈影响。
