Incidence of Cognitive Decline and Association with Changes in Sociodemographic, Lifestyle, and Health Indicators in Individuals aged 50 years and older: Prospective Cohort

Objectives: To identify the incidence of cognitive decline (CD) in an urban community-dwelling population aged 50 years and older in a 4-year follow-up period and its prospective association with sociodemographic factors, lifestyle and health conditions as well as with changes in these factors. Methods: This is a prospective cohort with a representative sample of people aged 50 years and older (n = 206) from Cambe, PR, where baseline data collection occurred in the year 2011 and the follow-up occurred in 2015. The incidence of CD was the outcome of this study, and its evaluation occurred through the Mini-Mental State Examination. Results: The incidence of CD was 13.1% over the 4 years of follow-up, and adjusted Poisson regression models (sex, age and age range) showed that this condition was prospectively associated with depression (adjusted relative risk (RR) = 3, 50, 95% CI = 1.65-7.43). When analyzing the effect of sociodemographic factor changes on CD, it was verified that the risk of CD was 2.86 times higher among the group that stopped having a companion in the 4 years of follow-up when compared to the group that maintained a companion in that same period, independent of confounding factors. Conclusion: The data suggest that the CD process begins before the age of 60 y and that aggravation is associated with potentially modifiable factors that can be approached by health services from the perspective of promotion, prevention and care.