Carotid Atherosclerosis Progression and Risk of Stroke---A Long-Term Follow up Study Based on a Taiwan Community Cohort and National Secondary Health Databases

Stroke prevention is a significant public health priority in the aging society. The Incidence of stroke increases rapidly after 55 years of age, and more than 30% of patients with stroke are left with disability requiring lifelong care and long-term rehabilitation. World Health Organization has projected that by 2030, stroke remains the second leading cause of death and one of the leading cause of disability-adjusted life-years worldwide. Measurement of carotid intima-media thickness (cIMT) is a non-invasive indicator of subclinical atherosclerosis and strongly associated with increased incidence of cardiovascular disease. The strong association and the underlying physiological mechanism have prompted the use of cIMT progression as a surrogate of cardiovascular disease in observational studies and clinical trials for assessing the effect of interventions or exposures. However, the association between cIMT progression and subsequent risk of cardiovascular disease has not been well-validated. Compared to non-Hispanic white, Chinese have higher stroke incidence, and types and risk profiles of stroke differs. A recent individual data meta-analysis has revealed that cIMT change was not associated with increased risk of cardiovascular disease and stroke. However, the results are not generalizable to Asians, as the analysis was restricted to populations from the US and Europe. Furthermore, the analysis focused on cIMT progression; information on formation of carotid plaque, another indicator of preclinical atherosclerosis, are limited. The Chin-Shan Community Cardiovascular Cohort study (CCCC) is a longitudinal study established in 1990. The National Health Insurance Program provides health coverage to 99% of people in Taiwan, creating an opportunity to form a unique national claims database. We propose to use CCCC and the secondary national health databases to establish a long-term follow-up database for the CCCC. The follow-up observation on stroke incidence will be extended to year 2011. Databases linkage will be conducted in the Collaboration Center of Health Information Application, Ministry of Health and Welfare, in which all databases are encrypted with no personal identifying information included. Using the dataset, the research project is proposed to investigate several issues, including the changes of carotid atherosclerosis, assessed using repeat measures of cIMT and carotid plaque, and its correlates; the association between change of carotid atherosclerosis and the subsequent risk of stroke. In addition, we will validate the accuracy of the National Health Insurance Research database in recording diagnosis of comorbidities or risk factors of stroke by comparison with CCCC data. The validation would be informative for assessing the extent of disease misclassifications and the quality of study results of the secondary health data analysis.

Project ID:PC10501-1293
External Project ID:MOST103-2314-B182-064-MY3