Cognitive aging across the life course in a low-income context: evidence from Malawi.

Three distinct cognitive trajectory groups were identified in rural Malawi among adults aged 45 years and older.

• 36% of respondents belonged to the 'high' cognition group characterized by a stable relative decline in cognition over time
• 46% belonged to the 'medium' cognition group experiencing intermediate relative decline by age 80 years
• 18% of respondents belonged to the 'low' cognition group experiencing the largest relative decline in cognition by age 80 years
• Latent-class trajectory models were used to identify these distinct trajectories
• Sample included 1214 adults aged ≥45 years from the Mature Adults Cohort of the Malawi Longitudinal Study of Families and Health

Longitudinal cognitive data spanning a decade were used to characterize aging trajectories in rural Malawi.

• Data were collected from 2012 to 2022
• The study used the Mature Adults Cohort of the Malawi Longitudinal Study of Families and Health (MLSFH)
• The study was conducted in a low-income country in sub-Saharan Africa
• 1214 adults aged ≥45 years were included in the analysis

Membership in higher cognition trajectory groups was associated with being male, having more education, better housing, and being born in a younger cohort.

• Individuals on higher cognition trajectories were more likely to be men
• Having completed a primary or secondary level of schooling was associated with higher cognition trajectory group membership
• Living in a house with a metal roof (a proxy for socioeconomic status) was associated with higher cognition trajectories
• Being born in younger cohorts was associated with higher cognition trajectory group membership
• Associations were estimated using fractional multinomial logit regression models

Heterogeneity exists in cognitive aging trajectories in Malawi, with a nontrivial subgroup experiencing accelerated cognitive decline.

• 18% of respondents belonged to the 'low' cognition group experiencing the largest relative decline by age 80 years
• The authors describe this subgroup as 'nontrivial' experiencing 'accelerated cognitive decline over the life course'
• The findings provide guidance for policymakers in developing targeted programs to prevent or reduce the burden of cognitive decline among high-risk groups
• Resources for treatment and care are described as limited in Malawi

Understanding of cognitive aging in low-income countries such as Malawi has been limited prior to this study.

• The study investigated heterogeneity in cognitive aging trajectories in rural Malawi, described as 'a low-income country in sub-Saharan Africa in which the current understanding of cognitive aging is limited'
• The study context is a rural, low-income setting, where resources for treatment and care are limited
• The results are intended to enhance healthy cognitive aging among older adults in Malawi