Mapping the Numbers of Dementia in Brazil: A Delphi Consensus Study.

Area of Science:

• Neurology
• Public Health
• Epidemiology

Background:

• The global dementia crisis is escalating, particularly in low- and middle-income countries (LMICs).
• Dementia prevalence data in Brazil is scarce, with existing studies focused on affluent urban areas.
• There is a critical need for comprehensive national dementia prevalence data in Brazil.

Purpose of the Study:

• To establish an expert consensus on the prevalence of all-cause dementia in Brazil.
• To analyze dementia prevalence across different age groups, sexes, and geographical regions within Brazil.
• To project future dementia case numbers in Brazil based on population aging.

Main Methods:

• A Delphi consensus process involving clinical and academic experts from across Brazil.
• Structured questionnaires incorporating literature data were used in multiple rounds.
• Consensus was achieved for over 70% of 15 prevalence estimates, including total, sex-specific, and regional data.

Main Results:

• A mean all-cause dementia prevalence of 8.5% (2.46 million individuals) was estimated for Brazilians aged ≥60 years in 2019.
• Dementia prevalence was higher in women (9.1%) than men (7.7%), exceeding 20% in individuals over 80.
• Regional variations were observed, with the Northeast (10.1%) showing higher prevalence than the South (7.3%).

Conclusions:

• Dementia impacts approximately 1 in 12 older Brazilians (≥60 years), with notable sex and geographical differences.
• Projections indicate a 3.6-fold increase in dementia cases by 2060, reaching 8.89 million.
• Urgent, targeted public health strategies are crucial for Brazil, providing a model for other LMICs facing similar challenges.