Estimating the prevalence of agitation in community-dwelling persons with Alzheimer's disease.

To estimate the prevalence of, and develop norms for, significant agitation in community-dwelling persons with Alzheimer's disease (AD), the authors applied three different criteria to persons with AD (n=235) and normal elderly control subjects (NEC; n=64). The criteria were used to identify the minimum total score on the Cohen-Mansfield Agitation Inventory (CMAI) that represents significant or "excessive" agitation and to estimate its prevalence. The "ultraliberal" criterion resulted in 99.1% of persons with AD and 56.6% of NEC being classified as "excessively" disturbed. The "liberal" and "conservative" criteria classified 66.7% and 68.2% of persons with AD, and no NEC, as "excessively" disturbed. The authors conclude that the best estimate of prevalence of excessive agitation in this population is 67.5%, and that individuals with CMAI scores of 0 to 14 probably should not be considered to have excessive agitation.