Supplementary Material for: Comparing Vascular Brain Injury and Stroke by Cranial Magnetic Resonance Imaging, Physician-Adjudication, and Self-Report: Data from the Strong Heart Study

<b><i>Background:</i></b> Epidemiologic studies often use self-report as proxy for clinical history. However, whether self-report correctly identifies prevalence in minority populations with health disparities and poor health-care access is unknown. Furthermore, overlap of clinical vascular events with covert vascular brain injury (VBI), detected by imaging, is largely unexamined. <b><i>Methods:</i></b> The Strong Heart Study recruited American Indians from 3 regions, with surveillance and adjudication of stroke events from 1989 to 2013. In 2010–2013, all 817 survivors, aged 65–95 years, underwent brain imaging, neurological history interview, and cognitive testing. VBI was defined as imaged infarct or hemorrhage. <b><i>Results:</i></b> Adjudicated stroke was prevalent in 4% of participants and separately collected, self-reported stroke in 8%. Imaging-defined VBI was detected in 51% and not associated with any stroke event in 47%. Compared with adjudication, self-report had 76% sensitivity and 95% specificity. Participants with adjudicated or self-reported stroke had the poorest performance on cognitive testing; those with imaging-only (covert) VBI had intermediate performance. <b><i>Conclusion:</i></b> In this community-based cohort, self-report for prior stroke had good performance metrics. A majority of participants with VBI did not have overt, clinically recognized events but did have neurological or cognitive symptoms. Data collection methodology for studies in a resource-limited setting must balance practical limitations in costs, accuracy, feasibility, and research goals.

**背景：** 流行病学研究常以自我报告作为临床病史的替代指标。然而，自我报告能否准确识别存在健康差异且医疗可及性较差的少数群体的患病率，目前尚不明确。此外，临床血管事件与影像学检出的隐性脑血管脑损伤（covert vascular brain injury, VBI）之间的重叠情况，在很大程度上尚未得到研究。
**方法：** 强心脏研究（Strong Heart Study）从3个地区招募美国印第安人，于1989年至2013年间开展卒中事件的监测与终点判定工作。2010年至2013年，所有817名年龄在65至95岁之间的存活受试者接受了脑部影像学检查、神经病史访谈及认知功能测试。本研究将VBI定义为影像学显示的梗死或出血灶。
**结果：** 经终点判定的卒中在受试者中患病率为4%，而单独收集的自我报告卒中患病率为8%。影像学确诊的VBI检出率为51%，其中47%的VBI受试者未伴随任何卒中事件。与临床终点判定结果相比，自我报告的灵敏度为76%，特异度为95%。存在经判定卒中或自我报告卒中的受试者，其认知功能测试表现最差；仅通过影像学检出隐性VBI的受试者，其认知表现处于中间水平。
**结论：** 在这项基于社区的队列研究中，既往卒中的自我报告具有良好的性能指标。大多数存在VBI的受试者未出现显性的、临床确诊的卒中事件，但确实存在神经或认知症状。在资源受限的研究场景中开展数据收集时，必须平衡成本、准确性、可行性与研究目标之间的实际限制。