Profiles of natural population cohort studies in the Belt and Road Initiative countries and their comparison with those in the Netherlands

  Objective  To examine the establishment and development of cohort studies among natural populations in Central Asia, South Asia and Commonwealth of Independent States (CIS) countries participating in the Belt and Road Initiative (BRI) and compare those with similar studies in the Netherlands for providing references to planning and performing of population cohort studies in the countries in the future.

  Methods  Through PubMed database, we searched for literatures published till March 1, 2019 on cohort studies conducted among natural populations in 20 Central Asia, South Asia and CIS countries participating in BRI. Information on establishment and development of the studies were extracted, analyzed and compared with similar studies conducted among the population in the Netherlands.

  Results  We totally retrieved 211 cohort studies with the followed-up population of 1 000 or more being carried out in the 20 countries participating in the BRI; of which, 164 (77.73%) and 47 (22.27%) were intra-country and international multicenter cohort studies. From the 211 retrieved cohort studies, 6 cohorts were secondarily selected for subsequent comparison with the 9 retrieved cohorts in the Netherlands. For the 6 cohorts conducted in the countries participating in the BRI, two were intra-country study; two were with the followed-up population of 100 000 or more; two were established in early 1990′s; and the number of published research literatures based on the 6 cohort studies was 400. In contrast, for the 9 retrieved cohort studies in the Netherlands, all were intra-country study; two were with the followed-up population of 100 000 or more; three were established in early 1980′s; and the number of published research literatures based on all the cohort studies was 1 500.

  Conclusion  A large number of natural population cohort studies had been conducted in Central Asia, South Asia and CIS countries participating in the Belt and Road Initiative; but the cohort studies had relatively small followed-up population and the quantity of published research literatures based on the cohort studies was also small compared to those of similar studies carried out in the Netherlands.