A community-based study of reporting demographic and clinical information concordance between informants and cognitively impaired participants

Background Understanding concordance between informants’ and cognitively impaired participants’ information reporting is crucial for Alzheimer’s and Alzheimer’s-related dementia studies. Methods The Brain Attack Surveillance in Corpus Christi-Cognitive is a community-based cohort study. Households in Nueces County, Texas, USA, were randomly identified. 330 dyads of participants and their named informants answered questions. Models were generated to examine which predictors, including age, gender, ethnicity, cognitive function, and relationship to informant, influenced answer discordance. Results For demographic items, female participants and participants with spouses/partners as informants had significantly less discordance, with incidence rate rations (IRRs) of 0.65 (CI = 0.44, 0.96) and 0.41 (CI = 0.23, 0.75), respectively. For health items, better cognitive function of the participant was associated with less discordance, with an IRR of 0.85 (CI = 0.76, 0.94). Conclusions Demographic information concordance is most associated with gender and informant–participant relationship. Level of cognitive function is most associated with concordance for health information. ClinicalTrials.gov identifier NCT03403257.