The TeCS follows a cohort of over 4,215 households, including over 10,000 individual participants, in the capital city of Tehran, Iran. The cohort included fixed and dynamic components. If the previously included members of a household had moved to another place, the new residents at the same zip code would be invited to participate. Additionally, the original recruited cohort would still be contacted and invited for a follow-up visit if still residing in Tehran. Moreover, different sections of the cohort included participants of different ages. The cardiovascular section enrolled household members aged 35 years and above. The psychological health section collected data from household members aged 15 years and above. Finally, the injury section collected data on all household members, regardless of age, from the head of the household.

Recruitment is ongoing