Missing Incidents in Individuals with Dementia Attending a Memory Clinic

People with dementia are at high risk of going missing and wandering in the community. Missing incidents are associated with unanticipated injuries, institutionalization, and death. Estimates of missing incidents in persons with dementia vary between studies.1-3 The Alzheimer's Disease and Related Disorders Association estimates that up to 60% of people with AD will wander and become lost in the community during the course of their disease.4 In addition to environmental factors, missing incidents may be associated with the clinical features of the individual, including the severity of dementia and the patterns of behavioral and psychological symptoms of dementia (BPSD). In Japan, the security of missing individuals with dementia is a growing concern, but no study has investigated missing incidents of individuals with dementia. The prevalence of missing incidents in individuals with dementia who attended memory clinic was examined. The clinical characteristics of individuals with dementia who go missing were also identified. Caregivers (N = 521) who agreed to participate in this study of outpatients with dementia attending a memory clinic completed a questionnaire. The questionnaire consisted of six questions: Were there any missing incidents during the last 12 months? How many missing incidents were there? How long was the individual missing? Who found the individual? Were there any troubles or injuries when the individual was found? Were there any observable patterns of BPSD in the missing individuals? The individuals with dementia included 423 with AD and 98 with vascular dementia or dementia with Lewy bodies. Individuals with severe disability who could not walk without assistance and those who were institutionalized were excluded. Severity of cognitive impairment was assessed using the Mini-Mental State Examination (MMSE).5 Written informed consent was obtained from all caregivers. The ethics committee of Tokyo Medical University approved this study. Values were expressed as means ± standard deviations. Statistical analysis was performed using the Student t-test and chi-square test. Although the terms “missing” (or getting lost) and “wandering” are considered to be distinct concepts,6 all types of missing incidents were included, including walking outdoors and wandering. Table 1 shows the differences in clinical characteristics between individuals with and without missing incidents. One hundred five (20%) individuals had gone missing during the last 12 months. Approximately 46% of them had only one missing incident, with the remaining 54% having several. There were no significant differences in age, sex, dementia subtype, or education between these individuals. Participants with missing incidents had significantly lower MMSE scores and longer dementia duration and were more likely to have BPSDs, such as delusion (21% vs 6%, P < .001), agitation and aggression (10% vs 2%, P < .001), sleep and nighttime behaviors (10% vs 1%, P < .001), refusal for caring (10% vs 1%, P < .001), and apathy (16% vs 2%, P < .001) than those without. Time missing ranged from a few hours to 3 days or more, with 80% or more of the individuals found within half a day. Although 22% returned home of their own accord, police or people other than their caregivers found many. When these individuals were found, 11% had complications, such as dehydration, infectious diseases, bruises, injuries, brain contusions, and traumatic subarachnoid hemorrhages. None were found dead. Of outpatients with dementia attending a memory clinic, approximately 20% had had missing incidents during the past 12 months. Although no association was found between caregiver factors (e.g., supervision level) and missing incidents, severity of cognitive impairment, disease duration, and BPSDs were associated with missing incidents. Eleven percent of participants had several complications when they were found, and more than half had more than one missing incident. The safe return of missing individuals with dementia is of paramount importance and calls for the concerted effort of the whole community to become more involved in identifying and assisting individuals with dementia, who are at a high risk of going missing. Conflict of Interest: The authors have no financial disclosures to declare. There are no conflicts of interest regarding this letter. Author Contributions: Okita, Hanyu: study concept and design, acquisition of participants and data, data analysis and interpretation, preparation of manuscript. Hirao, Shimizu, Umahara, Sakurai: acquisition of participants, data analysis. Sponsor's Role: None.