Scientific Concept of the National Cohort (status ... - Nationale Kohorte

A.1
A.1 Introduction and overview
Practical examples for such associations to be examined are:
� The handgrip strength (Level 1) and the risk of subsequent MI (approximately 2,000
cases at Level 1 within 5 years)
� The outcome of the step test (Level 2) and MI (approximately 400 cases at Level 2
within 5 years)
� The volume of the pancreas (imaging) and subsequent diabetes mellitus type 2 (approximately
6,800 cases at Level 1 within 5 years)
� A combined index of volume of the pancreas and the OGTT (both Level 2 and imaging)
and diabetes (approximately 16,000 cases at Level 1 within 10 years)
Table 1.4 shows that, at least for the study examples mentioned above, the intended study
size is sufficient, but also necessary, to detect excess risks in the range of 20 to 40% in the
full cohort and the different subcohorts. More elaborate estimates of statistical power are
presented in Sect. A.6.4.
Aside from these examples, Table 1.4 gives a robust impression of what may be achieved
in terms of epidemiologic findings for increasing time under observation. This is highlighted
by the fact that after 20 years of follow-up, approximately 23% (47,000) of the original cohort
participants will have died.
A.1.7 Outlook: The National Cohort as basis for collaborations and further
research projects
The planning phase of the National Cohort has already stimulated several related research
proposals and collaborations. They are based on, or developed in parallel with the National
Cohort but will be funded and/or governed independently (figure 1.4).
Planned studies, based on the National Cohort: For the following additional cohorts
planning has been started and/or feasibility studies are ongoing:
� Migrant Cohort: Germany is among the European countries with the highest proportions
of recent immigrants/migrants. The two larget immigrant groups in Germany are
the Turks (about 3.5 million) and migrants from the former Soviet Union (more than 2
million individuals). The concept of a Migrant Cohort of 25,000 migrants in selected recruitment
areas of the National Cohort (Berlin, Ruhr Area, Mannheim/Ludwigshafen)
has already been developed and currently is being tested in a feasibility study funded
by BMBF. Here, different recruitment schemes (using social and religious groups,
migrant organizations, local meeting places, social services, etc.) are being assessed
and existing tools in Turkish and Russian languages are used. Since it was not possible
to include this Migrant Cohort in the National Cohort due to financial restrictions,
we plan to apply for separate funding. There is strong support for the idea of a Migrant
Cohort from the Federal Ministry of Health (BMG) and several German Federal
States.
� Occupational Cohort: The National Cohort provides a unique opportunity to study
occupational health effects. For all study participants, complete (but crude) occupational
histories will be obtained by data retrieval from the national Institute for Employment
Research (Federal Employment Agency). These data will be linked to job
exposure matrices (JEM), to estimate possible past exposures to occupational risk
factors (see Sect. A.2.4.8). However, these data are not detailed enough to gain a
more precise understanding of the role of working conditions for specific health problems.
Therefore, an additional subcohort of the National Cohort shall be established in
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