Research and Psychology Services, VA San Diego Healthcare System (VASDHS), San Diego, California, USA.
Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, California, USA.
J Neurotrauma. 2022 Jan;39(1-2):238-242. doi: 10.1089/neu.2020.7516. Epub 2021 Apr 30.
We examined the association between cognitive functioning and health-related quality of life (HR-QOL) in military veterans with a history of mild traumatic brain injury (mTBI) using two methods to assess cognition: mean performance on cognitive composite scores and across-test intraindividual variability (IIV). The sample included 73 veterans (84.9% male; age, mean = 32.47 years) who completed neuropsychological testing and self-report questionnaires ∼7 years post-injury. Three cognitive composite scores representing mean performance were computed, including memory, attention/processing speed (A/PS), and executive functioning (EF). Three IIV indices were also calculated reflecting degree of dispersion across the same cognitive domains: memory-IIV, A/PS-IIV, and EF-IIV. The Posttraumatic Stress Disorder (PTSD) Checklist-Military Version (PCL-M) was used to assess current PTSD symptoms, and the World Health Organization Quality of Life Short Version Physical Health domain was used to assess HR-QOL. Hierarchical linear regressions adjusting for PTSD symptoms demonstrated that IIV indices, but not mean cognitive composite scores, significantly predicted HR-QOL. Specifically, memory-IIV, A/PS-IIV, and EF-IIV, when taken together, made an independent and significant contribution to the prediction of HR-QOL. Examination of the standardized coefficients showed that the A/PS-IIV index was uniquely associated with HR-QOL, such that higher A/PS-IIV scores significantly predicted poorer HR-QOL. Our results are the first to show that, in veterans with remote mTBI histories, greater fluctuations in cognitive performance significantly contribute to poorer HR-QOL, even after accounting for PTSD symptom severity. Moreover, findings suggest that, compared to traditional mean cognitive performance scores, measures of IIV may represent more sensitive indicators of clinical outcome and better align with subjective experiences of distress.
我们使用两种方法评估认知功能，即认知综合评分的平均表现和跨测试个体内变异性（IIV），来研究有轻度创伤性脑损伤（mTBI）病史的退伍军人的认知功能与健康相关生活质量（HR-QOL）之间的关系。该样本包括 73 名退伍军人（84.9%为男性；年龄，平均=32.47 岁），他们在受伤后约 7 年完成了神经心理学测试和自我报告问卷。计算了三个代表平均表现的认知综合评分，包括记忆、注意力/处理速度（A/PS）和执行功能（EF）。还计算了三个反映同一认知领域内分散程度的 IIV 指数：记忆-IIV、A/PS-IIV 和 EF-IIV。使用创伤后应激障碍检查表-军事版本（PCL-M）评估当前的 PTSD 症状，使用世界卫生组织生活质量简短版本的身体健康领域评估 HR-QOL。在调整 PTSD 症状后进行的分层线性回归表明，IIV 指数而不是平均认知综合评分显著预测 HR-QOL。具体而言，当一起考虑时，记忆-IIV、A/PS-IIV 和 EF-IIV 对 HR-QOL 的预测具有独立且显著的贡献。对标准化系数的检查表明，A/PS-IIV 指数与 HR-QOL 独特相关，即 A/PS-IIV 评分较高显著预测 HR-QOL 较差。我们的研究结果是首次表明，在有远程 mTBI 病史的退伍军人中，认知表现的波动更大，即使在考虑 PTSD 症状严重程度后，也会显著导致 HR-QOL 较差。此外，研究结果表明，与传统的平均认知表现评分相比，IIV 测量可能代表更敏感的临床结果指标，并且更好地与主观痛苦体验保持一致。
