Persistence of Neuropsychiatric Symptoms and Dementia Prognostication: A Comparison of Three Operational Definitions of Mild Behavioral Impairment

ABSTRACT INTRODUCTION This study compares three operational definitions of mild behavioral impairment (MBI) in the context of MBI prevalence estimates and dementia risk modeling. METHODS Participants were dementia-free older adults (n=13701) from the National Alzheimer’s Coordinating Center. Operational definitions of MBI were generated based on neuropsychiatric symptoms at one (OV), two-consecutive (TCV), or >2/3 (TTV) of dementia-free study visits. Definitions were compared in prevalence and in Cox regressions using MBI to predict incident dementia. RESULTS OV MBI was the most prevalent (54.4%), followed by TCV (32.3%) and TTV (26.7%) MBI. However, OV MBI had the lowest rate of incident dementia (HR=2.54, 95%CI: 2.33–2.78) and generated poorer model metrics than TCV MBI (HR=4.06, 95%CI: 3.74–4.40) and TTV MBI (HR=5.77, 95%CI: 5.32–6.26). DISCUSSION Case ascertainment with longer timeframe MBI operational definitions may more accurately define groups at risk of dementia in datasets lacking tools designed to detect MBI. HIGHLIGHTS Mild behavioral impairment (MBI) can identify older adults at risk of dementia. Neuropsychiatric symptom (NPS) assessment tools can be proxy measures for MBI. Hazard for dementia was highest for MBI defined by NPS presence at >2/3 of visits.