Kawai Andrew, Hui Samuel, Beare Richard, Srikanth Velandai K, Sundararajan Vijaya, Ma Henry, Phan Thanh G
School of Clinical Sciences at Monash Health, Stroke and Aging Research Group, Clinical Trials, Imaging & Informatics Division, Melbourne, VIC, Australia.
Department of Neurology, Monash Health, Melbourne, VIC, Australia.
Front Neurol. 2022 Aug 22;13:983512. doi: 10.3389/fneur.2022.983512. eCollection 2022.
There has been a decline in the stroke incidence across high income countries but such knowledge exists at Country or State rather than areal unit level such local government area (LGA). In this disease mapping study, we evaluate if there are local hot spots or temporal trends in TIA rate. Such knowledge will be of help in planning healthcare service delivery across regions.
Linked hospital discharge data (Victorian Admitted Episodes Dataset or VAED) was used to collect TIA (defined by ICD-10-AM codes G450-G459) cases from 2001 to 2011. The State of Victoria is the second most populous state in Australia, with a population of 6.7 million and can be divided into 79 administrative units or LGA. The data is anonymized and contains residence of the patient in terms of LGA but not exact location. The date of the TIA event when the patient is admitted to hospital is provided in the dataset. The number of TIAs per year was aggregated for each LGA. Standardized TIA ratios were calculated by dividing actual over expected cases for each LGA per year. We used Integrated Nested Laplace Approximation (INLA) to perform spatial and spatiotemporal regression, adjusting for hypertension, sex and population, age (≥60), and socio-economic status (SES) decile within the LGA. The final model was chosen based on the lowest the Deviance Information Criterion (DIC) and Watanabe-Akaike information criteria (WAIC).
Choropleth maps showed a higher standardized TIA ratios in North-West rural region. Compared to the baseline model (DIC 13,159, WAIC 13,261), adding in a spatial random effect significantly improved the model (DIC 6,463, WAIC 6,667). However, adding a temporal component did not lead to a significant improvement (DIC 6,483, WAIC 6,707).
Our finding suggests a statically significant spatial component to TIA rate over regional areas but no temporal changes or yearly trends. We propose that such exploratory method should be followed by evaluation of reasons for regional variations and which in turn can identify opportunities in primary prevention of stroke, and stroke care.
高收入国家的中风发病率有所下降，但此类信息存在于国家或州层面，而非像地方政府区域（LGA）这样的地域单位层面。在这项疾病地图绘制研究中，我们评估短暂性脑缺血发作（TIA）发生率是否存在局部热点或时间趋势。此类信息将有助于规划跨区域的医疗服务提供。
使用关联的医院出院数据（维多利亚州住院病例数据集或VAED）收集2001年至2011年的TIA（由ICD - 10 - AM编码G450 - G459定义）病例。维多利亚州是澳大利亚人口第二多的州，有670万人口，可分为79个行政单位或LGA。数据已匿名化，包含患者在LGA方面的居住地，但不包含确切位置。数据集中提供了患者入院时TIA事件的日期。每年每个LGA的TIA数量进行了汇总。通过将每个LGA每年的实际病例数除以预期病例数来计算标准化TIA比率。我们使用集成嵌套拉普拉斯近似法（INLA）进行空间和时空回归，并对高血压、性别、人口、年龄（≥60岁）以及LGA内的社会经济地位（SES）十分位数进行调整。最终模型基于最低的离差信息准则（DIC）和渡边赤池信息准则（WAIC）进行选择。
分级统计图显示西北农村地区的标准化TIA比率较高。与基线模型（DIC 13159，WAIC 13261）相比，添加空间随机效应显著改善了模型（DIC 6463，WAIC 6667）。然而，添加时间成分并未带来显著改善（DIC 6483，WAIC 6707）。
我们的研究结果表明，在区域范围内TIA发生率存在统计学上显著的空间成分，但没有时间变化或年度趋势。我们建议，在采用这种探索性方法之后，应评估区域差异的原因，这反过来可以确定中风一级预防和中风护理方面的机会。
