Surprising Results

Letters to the Editor Decline in the Incidence and Prevalence of Dementia An Analysis of Outpatient Claims Data by Bernhard Michalowsky, Wolfgang Hoffmann, Steffi Riedel-Heller, Claudia Kohring, Stefan Teipel, Manas K. Akmatov, Jens Bohlken, and Jakob Holstiege in issue 14/2025

I wish to thank the authors for publishing this important article (1). The results have come as a (positive) surprise to me as the possible explanatory models are in themselves limited and do not conform to the prognoses, most of all those of the Dementia Forecasting Collaborators (2).

As the authors themselves comment in the limitations section, evaluating outpatient claims data is only one important approach to estimating the actual incidence rates of dementia. Diverse factors of influence might play a part: on the one hand, no adequate diagnostic evaluation for dementia is carried out, especially in the general practice setting, because of time constraints (3). On the other hand, a survey of the German National Association of Statutory Health Insurance Funds from 2024 showed that waiting times for specialist medical consultations have increased, which in turn may mean a hurdle for patients with cognitive impairments.

It is even more surprising that incidence rates of mild cognitive impairments have notably increased. Here, too, selective differentiation is possible only by carrying out comprehensive neuropsychological tests (even more ideal would be biomarker analysis), but these are mostly the preserve of memory clinics.

Lifestyle modifications may have a role in the younger generations, but in the older generations—which are primarily affected by dementia—they are of lesser importance and therefore cannot explain this trend. For this reason, my view of the optimistic conclusions that the incidence of dementia is actually falling is somewhat critical—even though this would be extremely positive.

It would be desirable to include in addition to outpatient claims data at least to collect further datasets with random collection of the diagnostic instruments and to include registry data as soon as this becomes possible.

DOI: 10.3238/arztebl.m2025.0181

PD Dr. med. Arnim Quante

Friedrich von Bodelschwingh-Klinik

Klinik für Psychiatrie, Psychotherapie und Psychosomatik

Berlin

References

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.

2. GBD 2019 Dementia Forecasting Collaborators: Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: An analysis for the Global Burden of Disease Study 2019. Lancet Public Health 2022; 7: e105–e25.

3. Eichler T, Thyrian R, Teipel S, Hoffmann W: Früherkennung der Demenz in der Hausarztpraxis: Subjektive Gedächtnislücken sind kein geeigneter Indikator. Dtsch Arztebl 2015; 112: [15]