Rethinking morbidity compression and morbidity expansion: Differential developments of morbidity and social inequalities in terms of health impairments and chronic diseases.

• Applicant: Professor Dr. Siegfried Geyer
• Subject Area: Empirical Social Research ; Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471338999

The proposed project builds on the findings of a previous one where it was examined whether the long-term developments of myocardial infarction, stroke and functional impairments can be described as morbidity compression, morbidity expansion or as a dynamic equilibrium. The second main topic was related to the development of related social inequalities in health over time. Unexpectedly it turned out that in myocardial infarction and in other health-related endpoints compression occurred in the higher age groups, while we found expansion in the younger ones.Based in these findings it will be examined how chronic obstructive pulmonary disease (COPD) as an important determinant of population health develops over time and whether the related social gradients are narrowing or broadening. In addition, it will be considered whether the disease is developing differently according to the age groups considered, i.e., whether compression and expansion are occurring in the same disease. COPD-related analyses are performed both using claims data and surveys, thus making it possible to replicate findings derived from different types of data. This also makes it possible to perform supplementary analyses that may be possible with one of the datasets, but not with the other. According to present knowledge, the longitudinal developments of myocardial infarctions and stroke in higher age groups can be described as morbidity compression, and it has to be examined to what extent this can be attributed to increasing preventive medications over time. Morbidity compression and expansion are concepts describing developments at population level, i.e., numbers of morbidity or mortality may not necessarily be derived from the same individuals. The third part of the project leaves this perspective by considering the longitudinal development of comorbidities of individuals with stroke, myocardial infarction and COPD. This implies that time periods spent in states of disease and disability may increase, while morbidity compression may occur at population level. In the final part of the project the findings on the three concepts and diseases describing morbidity development will be integrated into a unified concept of morbidity development in the population.

• DFG Programme: Research Grants