Letters to the Editor
In Reply
We want to thank the correspondents for their comments and remarks regarding the limitations and possible explanations of our findings (1). As Quante explained, outpatient claims data are only one approach to reflect changes in the incidence and prevalence of disorders. We pointed out methodological limitations, among others, possible biases arising from coding practices, financial incentives, and a shift in diagnostic evaluation to inpatient settings. Aspects such as time constraints in general practice or long waiting times for specialist consultations, also mentioned by Quante, may also affect the documentation. Our results should therefore not be seen as a confirmed decline in the risk of dementia. They merely reflect the actual diagnostic behavior and trends, not a change in dementia, even if that would constitute a positive message.
The mention of the parallel increase in mild cognitive disorders (MCI) is particularly relevant, especially in view of new therapeutic approaches that are deployed at early stages of the disease. The number of documented diagnoses of MCI, however, remains very low. The causes of this will have to be investigated in future research projects. We also agree with the stated cohort effects. Our analysis showed that declines in incidence rates were more pronounced in younger cohorts. Better education, prevention, and treatment of cardiovascular risk may have lowered the risk in younger cohorts, since this population benefited most from such measures.
Our results should, therefore, be interpreted conservatively. We attempted to discuss the possible causes of the trends (dementia risk, diagnostic behavior, structural factors) equally, without prioritizing any one. For future studies, we consider linking claim, registry, and clinical data to enable valid conclusions about actual changes in dementia risk.
DOI: 10.3238/arztebl.m2025.0182
On behalf of the authors
PD Dr. rer. pol. Dr. rer. med. habil. Bernhard Michalowsky
Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Rostock/Greifswald, AG Patienten-berichtete Outcomes & Gesundheitsökonomie, Greifswald, und McMaster University, Health Research Methods, Evidence and Impact, Hamilton, Kanada
bernhard.michalowsky@dzne.de
Conflict of interest statement
The authors of both letters to the editor declare that no conflict of interest exists.
| 1. | Michalowsky B, Hoffmann W, Riedel-Heller S, et al.: Decline in incidence and prevalence of dementia: An analysis of outpatient claims data. Dtsch Arztebl Int 2025; 122: 373–8 VOLLTEXT CrossRef MEDLINE PubMed Central |
