Disruptive Behavior as a Predictor in Alzheimer Disease

Abstract

Disruptive behavior is common in Alzheimer disease (AD). There are conflicting reports regarding its ability to predict cognitive decline, functional decline, institutionalization, and mortality. To examine whether the presence of disruptive behavior has predictive value for important outcomes in AD. Using the Columbia University Scale for Psychopathology in Alzheimer Disease (administered every 6 months, for a total of 3438 visit-assessments and an average of 6.9 per patient), the presence of disruptive behavior (wandering, verbal outbursts, physical threats/violence, agitation/restlessness, and sundowning) was extracted and examined as a time-dependent predictor in Cox models. The models controlled for the recruitment cohort, recruitment center, informant status, sex, age, education, a comorbidity index, baseline cognitive and functional performance, and neuroleptic use. Five university-based AD centers in the United States and Europe (Predictors Study). Four hundred ninety-seven patients with early-stage AD (mean Folstein Mini-Mental State Examination score, 20 of 30 at entry) who were recruited and who underwent semiannual follow-up for as long as 14 (mean, 4.4) years. Cognitive (Columbia Mini-Mental State Examination score, < or = 20 of 57 [approximate Folstein Mini-Mental State Examination score, < or = 10 of 30]) and functional (Blessed Dementia Rating Scale score, parts I and II, > or = 10) ratings, institutionalization equivalent index, and death. At least 1 disruptive behavioral symptom was noted in 48% of patients at baseline and in 83% at any evaluation. Their presence was associated with increased risks of cognitive decline (hazard ratio 1.45 [95% confidence interval (CI), 1.03-2.03]), functional decline (1.66 [95% CI, 1.17-2.36]), and institutionalization (1.47 [95% CI, 1.10-1.97]). Sundowning was associated with faster cognitive decline, wandering with faster functional decline and institutionalization, and agitation/restlessness with faster cognitive and functional decline. There was no association between disruptive behavior and mortality (hazard ratio, 0.94 [95% CI, 0.71-1.25]). Disruptive behavior is very common in AD and predicts cognitive decline, functional decline, and institutionalization but not mortality.