The Temporal Relationship between Pain Intensity and Pain Interference and Incident Dementia.

Abstract

Chronic pain is common among older adults and is associated with cognitive dysfunction based on cross-sectional studies. However, the longitudinal association between chronic pain and incident dementia in community-based samples is unknown. We aimed to evaluate the association of pain intensity and pain interference with incident dementia in a community-based sample of older adults. Participants were 1,114 individuals 70 years of age or older from Einstein Aging Study (EAS), a longitudinal cohort study of community-dwelling older adults in the Bronx County, NY. The primary outcome measure was incident dementia, diagnosed using DSM-IV criteria. Pain intensity and interference in the month prior to first annual visit were measured using items from the SF-36 questionnaire. Pain intensity and pain interference were assessed as predictors of time to incident dementia using Cox proportionate hazards models while controlling for potential confounders. Among participants, 114 individuals developed dementia over an average 4.4 years (SD=3.1) of follow-up. Models showed that pain intensity had no significant effect on time to developing dementia, whereas higher levels of pain interference were associated with a higher risk of dementia. In the model that included both pain intensity and interference as predictors of incident dementia, pain interference had a significant effect on incident dementia, and pain intensity remained non-significant. As a potential remediable risk factor, the mechanisms linking pain interference to cognitive decline merit further exploration.