Yazd health Study (YAHS) is a prospective cohort study, with 10,000 participants, established in 2013 in Yazd, Iran. The word “cohort” has been adopted into epidemiology to define a set of people followed over a period of time. W.H. Frost, an epidemiologist from the early 1900s, was the first to use the word “cohort” in his 1935 publication assessing age-specific mortality rates and tuberculosis.
The modern epidemiological definition of the word now means a “group of people with defined characteristics who are followed up to determine incidence of, or mortality from, some specific disease, all causes of death, or some other outcomes.
In Iran, there are several large cohort studies running with different follow-up period from a year to over one decade. The study participants of these studies are individual patients of a certain geographic area (Golestan Cohort study -GCS), certain group of patients (Shahrood Eye Study), elderly (Amirkola Cohort Study) and pregnant women studies.
Most famous cohort studies in Iran focused on non-communicable diseases which are the main cause of mortality and morbidity in the country.
Yazd Health Study is a population based cohort study established in Yazd province in central Iran with over 1,000,000 population. YAHS has already finished the recruitment phase and the follow up phase has been started. Yazd Bio Bank (Zist Bank Yazd- ZIBA) is a parallel project of YAHS which is a population based biobank with bio-samples of the same 10.000 participants.
Due to the high rate of consanguinity in Yazd province (over 40%) and a very high prevalence of chronic diseases there, a great opportunity for family aggregation studies to find gene- environment interactions and genome wide association studies (GWAS) in this part of the world is available.
YAHS has several sub studies including Yazd Nutrition Study (Motale e Taghzieh Mardom Yazd- Tamiz), Yazd Electromagnetic Health Study (Motale e Salamat Mayadin Electro Meghnatis- MOSAMA) and Yazd Heavy Metals Study (HEMES). These studies are all funded and are in different phases of progress. Overall, more than 1,000 variables have been collected from each participants using the highest available standards. Ethics approval of YAHS was issued by the ethics committee of Shahid Sadoughi University of Medical Sciences and written informed consents were obtained from all participants.