Objective: This study aims to identify whether pain and dementia-related behavior are associated withdifferent types of activities in nursing home residents, controlled for dementia severity.Design... Show moreObjective: This study aims to identify whether pain and dementia-related behavior are associated withdifferent types of activities in nursing home residents, controlled for dementia severity.Design: Cross-sectional baseline data from the multicomponent cluster randomized controlled COSMOS trial (acronymfor Communication, Systematic pain treatment,Medication review, Organization of activities, and Safety).Setting and Participants: A total of 723 patients from 33 Norwegian nursing homes with 67 units(clusters). Participants aged >= 65 years, with a life expectancy of >6 months, and with valid data onactivity were eligible for inclusion.Methods: Activity was operationalized in time (hours per week) and type (cognitive, social, physical, andno activity). Cognitive function was assessed using the Mini-Mental State Examination (MMSE), painwith the Mobilization-Observation-Behavior-Intensity-Dementia-2 Pain Scale (MOBID-2), and behaviorwith the Neuropsychiatric Inventory Nursing Home version (NPI-NH). Analyses were performed usinglinear and logistic regression. Sensitivity analyses for dementia severity were performed to account foreffect modification.Results: A total of 289 participants were included (mean age 86.2 [SD 7.6]; 74% female). A higher painscore was associated with less time spent on activity in participants with severe dementia (estimate0.897, P = .043). A higher score for the NPI-NH mood cluster (depression and anxiety) was associatedwith a higher likelihood of participation in cognitive activities (odds ratio [OR], 1.073; P ¼ .039). Apathy(OR, 0.884; P = .041) and lack of inhibition (OR, 0.904; P = .042) were associated with a lower likelihoodof participation in social activities as well as no engagement in activities (apathy OR, 0.880; P = .042; lackof inhibition OR, 0.894; P = .034).Conclusion and Implications: Pain and dementia-related behavior may influence the participation inactivities in the nursing home. There is an urgent need to investigate what type of activity stimulatespeople in different stages of dementia. Show less