[Dementia in nonagenarians. Systematic review of population-based studies with Spanish data]. / Demencia en nonagenarios. Revisión sistemáticade estudios poblacionales con datos de España.

INTRODUCTION: Ageing is associated with the quasi exponential getting up of dementia prevalence and incidence until 85 years, but the data in the oldest-old are controversial. AIM. Systematic review of population based studies that analyze prevalence and incidence of dementia in the oldest-old, specifically in nonagenarians. PATIENTS AND METHODS: Systematic review in Medline database of population based surveys describing prevalence or incidence in older than 90, published from 1989. 459 papers were identified, but of the 170 population-based detailed reviewed, 41 studies accomplished the inclusion criteria (Pamplona, Gerona and NEDICES Study are included). RESULTS: The dementia prevalence described in nonagenarians has a range of 25-54%. The dementia incidence in older than 90 has a range of 47-174 cases per 1,000 people/year, being greater in females. In the oldest-old a variable prevalence and incidence of dementia was described in the selected studies. Some authors consider that exist an exponential increase in the dementia prevalence and another ones indicate a slowing of growth in nonagenarians. CONCLUSIONS: This review is concordant with a persistent not exponential increase in prevalence and incidence of dementia in nonagenarians.

Demencia en nonagenarios. Revisión sistemática de estudios poblacionales con datos de España / Dementia in nonagenarians. Systematic review of population-based studies with spanish data

Introducción. El envejecimiento se asocia con un aumento casi exponencial en la prevalencia e incidencia de la demencia hasta los 85 años, pero los datos en los ‘muy ancianos’ son controvertidos. Objetivo. Revisión sistematizada de estudiospoblacionales sobre prevalencia e incidencia de la demencia en los ‘muy ancianos’, y específicamente en nonagenarios.Pacientes y métodos. Revisión sistemática en Medline de estudios poblacionales sobre prevalencia e incidencia de la demencia, con descripción de casos de nonagenarios publicados desde 1989. De 459 publicaciones descritas, se analizaron 170 estudios poblacionales, y se seleccionaron 41 que cumplían los criterios de inclusión (se incluyen los estudios españoles de Pamplona, Gerona y NEDICES).Resultados. La prevalencia de la demencia en nonagenarios oscila entre el 25-54%, y la incidenciaentre 47-174 casos por 1.000 personas/año, y es mayor en las mujeres. Los estudios seleccionados muestran gran variabilidad en la prevalencia e incidencia de la demencia en los muy ancianos. Algunos autores consideran que en este grupo de edad sigue existiendo un incremento exponencial de casos de demencia, y otros describen un enlentecimiento de este incremento.Conclusión. En los nonagenarios se produce un incremento no exponencial en la prevalencia e incidencia de la demencia

Introduction. Ageing is associated with the quasi exponential getting up of dementia prevalence and incidence until 85 years, but the data in the oldest-old are controversial. Aim. Systematic review of population based studies that analyze prevalence and incidence of dementia in the oldest-old, specifically in nonagenarians. Patients and methods. Systematic review in Medline database of population based surveys describing prevalence or incidence in older than 90, published from1989. 459 papers were identified, but of the 170 population-based detailed reviewed, 41 studies accomplished the inclusion criteria (Pamplona, Gerona and NEDICES Study are included). Results. The dementia prevalence described in nonagenarians has a range of 25-54%. The dementia incidence in older than 90 has a range of 47-174 cases per 1,000 people/year, being greater in females. In the oldest-old a variable prevalence and incidence of dementia was described in the selected studies.Some authors consider that exist an exponential increase in the dementia prevalence and another ones indicate a slowing of growth in nonagenarians. Conclusions. This review is concordant with a persistent not exponential increase in prevalence andincidence of dementia in nonagenarians