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

A.2 Scientific background and rationale for study elements
A.2 Scientific background and rationale for study
elements
A.2.1 Introduction
For the planning of the National Cohort, several different perspectives have been taken
into consideration in deciding upon its specific research emphases and choice of study elements,
regarding both the specific diseases to be studied and risk factor information to be
collected.
From a public health perspective, clearly the National Cohort should focus on diseases
and conditions that are major causes of death and healthy years of life lost and that constitute
a high burden on the German health care systems in terms of cost. Likewise, on
the risk determinant side, the National Cohort should naturally focus on identifying factors
that are likely to explain large proportions of these various major diseases and that in large
part could represent common risk factors for diseases in different major categories. From a
societal perspective, the cohort should focus on diseases and health problems that will increase
as a result of the aging population structure. In addition, the National Cohort should
address the topic of social disparities as a possible causal factor of health inequalities, in
view of the increasing gap between individuals suffering from deprivation, on the one hand,
and individuals living in relative prosperity, on the other.
From a person’s own individual perspective, an important consideration for identifying the
disease groups to be studied in the National Cohort is that there is substantial evidence that
disease occurrence can potentially be influenced, i.e., disease risk increased or decreased
or disease occurrence accelerated or delayed, through one’s behavior. Many prior studies
have summarized such health-related behaviors within the term “lifestyle”, which includes
physical activity, alcohol consumption, smoking, and diet. This classic concept of lifestyle,
however, does not fully and sufficiently reflect the reality of life today; in particular, psychosocial
factors, such as personality, social networking, and perceived stress at work or at
home need to be added to this classic concept.
From an epidemiologic perspective, research should focus on questions that truly require
a long-term, prospective approach in order to be answered properly. This excludes diseases
and conditions which are rare and could be examined better in a register or case-control
study design, or research questions that could be addressed by cross-sectional studies.
Finally, from both an epidemiologic and clinical perspective, such a long-term project
must allow for innovations that can be transferred to prevention and/or to clinical settings.
Integrating these different perspectives the following general decisions were reached:
� For disease outcomes, the core focus of the study will be on CVD, diabetes, cancer,
neurologic and psychiatric diseases, respiratory diseases, infectious diseases, and
musculoskeletal diseases, as these disease groups best reflect the defined perspectives.
� Intensive use will be made of diagnostic work-up methods known from clinical settings
and scores previously validated for other purposes to assess preclinical and clinical
phenotypes, with an emphasis on methods that can be used over a long, prospective
study period.
� For risk determinants, particular emphasis will be placed on areas in which major,
common risk factors can be identified for diverse types of chronic disease and on
modern tools for determining risk factors; these main areas include lifestyle-related
risk determinants (diet, physical activity, excess body weight, and related metabolic
and physical fitness conditions), psychosocial factors, chronic infections, immune factors,
and bacterial microflora. In addition, the cohort will address questions in relation
to occupational and environmental exposures.
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A.2