Cardiovascular mortality in a Western Asian country: results from the Iran Cohort Consortium
1Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
2Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3Department of Biostatistics and Epidemiology, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
4Digestive Diseases Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
5Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
6Isfahan Cardiovascular Research center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran.
7Ophthalmic Epidemiology Research Center, Shahroud University of Medical Sciences, Shahroud, Iran.
8Department of epidemiology and biostatistics, Health school, Isfahan University of Medical Sciences, Isfahan, Iran.
9Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran.
10Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
11Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
12Department of Biomedical Data Sciences, LUMC, Leiden, The Netherlands.
Objectives: Cardiovascular mortality in Western Asia is high and still rising. However, most data documented on risk prediction has been derived from Western countries and few population-based cohort studies have been conducted in this region. The current study aimed to present the process of pooling data and cardiovascular disease (CVD) mortality incidences for four Iranian cohorts.
Methods: From the Iran Cohort Consortium, the Golestan Cohort Study (GCS), Tehran Lipid and Glucose Study, Isfahan Cohort Study (ICS) and the Shahroud Eye Cohort Study (ShECS) were eligible for the current study since they had appropriate data and follow-up visits. Age-standardised CVD mortality rates were estimated for ages 40-80 and 40-65 years. Cox regression was used to compare mortalities among cohorts. Adjusted marginal rates were calculated using Poisson regression.
Results: Overall, 61 291 participants (34 880 women) aged 40-80 years, free of CVD at baseline, were included. During 504 606 person-years of follow-up, 1981 CVD deaths (885 women) occurred. Age-standardised/sex-standardised premature CVD mortality rates were estimated from 133 per 100 000 person-years (95% CI 81 to 184) in ShECS to 366 (95% CI 342 to 389) in the GCS. Compared with urban women, rural women had higher CVD mortality in the GCS but not in the ICS. The GCS population had a higher risk of CVD mortality, compared with the others, adjusted for conventional CVD risk factors.
Conclusions: The incidence of CVD mortality is high with some differences between urban and rural cohorts in Iran as a Western Asian country. Pooling data facilitates the opportunity to globally evaluate risk prediction models.
Keywords: cardiovascular diseases; cohort studies; epidemiology of cardiovascular diseases; mortality.