Do Individual and Geographical Deprivation Have the Same Impact on the Risk of Dementia? A 25-Year Follow-up Study.

OBJECTIVES

To determine the impact of both individual psychosocioeconomic precariousness and geographical deprivation on risk of dementia in older adults followed-up for 25 years.

METHOD

The sample consisted of 3,431 participants aged 65 years or over from the PAQUID cohort study. Individual psychosocioeconomic precariousness was measured computing eight economic and psychosocial indicators. Geographical deprivation was assessed by the FDep99 index, consisting of four community socioeconomic variables. For both measures, the fourth quartile of the distribution was considered as the more precarious or deprived category, while the first quartile was considered as the less precarious or deprived one. Clinical dementia diagnosis was assessed all along study follow-up. The association between individual psychosocioeconomic precariousness, geographical deprivation and risk of dementia was assessed using illness-death regression models adjusted for age, sex, depression, psychotropic drug consumption, comorbidities, disability, and body mass index, while accounting for death as a competing event.

RESULTS

The risk of dementia was higher for the more psychosocioeconomic precarious participants (HR = 1.51; 95% CI: 1.24-1.84). No increased risk of dementia was found for those living in communities with high index of deprivation.

DISCUSSION

Psychosocioeconomic precariousness, but not geographical deprivation, is associated with a higher risk of dementia.