Effectiveness of Environment-Based Interventions That Address Behavior,Perception,and Falls in People With Alzheimer’s Disease and Related Major Neurocognitive Disorders: A Systematic Review

Search Strategy

Inclusion criteria for this review were as follows: Studies were published in English in peer-reviewed scientific journals between January 2006 and April 2014; intervention approaches were within the scope of practice of occupational therapy (AOTA, 2014); and study participants were diagnosed with AD or a related disorder. Although the database searches used the aforementioned dates as parameters, two articles published before 2006 that were not included in previous reviews were located by hand searching reference lists and were included because they provide valuable information to answer the question. Using the evidence hierarchy described by Sackett, Rosenberg, Muir Gray, Haynes, and Richardson (1996), Level IV (descriptive outcome studies such as single-subject and case series designs) and Level V (case reports, narrative literature reviews, and consensus statements) evidence were included only when Level I (systematic reviews, meta-analyses, and randomized controlled trials [RCTs]), Level II (two-group nonrandomized studies), or Level III (one-group, nonrandomized studies) evidence was not found. The review excluded qualitative studies, data from presentations, conference proceedings, non–peer-reviewed research reports, dissertations, and theses.

Search terms were developed by the methodology consultant to the AOTA EBP Project and AOTA staff in consultation with the review authors and the advisory group. Search terms were developed not only to capture pertinent articles but also to ensure that the terms relevant to the specific thesaurus of each database were included. See Supplemental Table 1 (available online at http://otjournal.net; navigate to this article, and click on “Supplemental”) for the electronic search terms and a sample strategy used for this question. A medical research librarian with experience in completing systematic review searches conducted all initial searches, and the review team followed up with additional searches.

Databases and sites searched included MEDLINE, PsycINFO, CINAHL, OTseeker, and the Cochrane Database of Systematic Reviews. Additionally, reference lists from articles included in systematic reviews were examined, and hand searches of selected journals ensured that all appropriate articles were included.

Study Selection, Data Extraction, and Risk-of-Bias Assessment

The methodology consultant to the EBP Project completed the first round, and the review authors the second round, of eliminating references on the basis of citations and abstracts. The review authors then retrieved full-text versions of potential articles and determined final inclusion in the review on the basis of relevance to the question, study quality, level of evidence, and inclusion and exclusion criteria. Disagreements were resolved through consensus. Each retained article was appraised and key information extracted to an evidence table that provides a summary of the methods and findings of the article. Supplemental Table 2 (online) summarizes the characteristics, including specific interventions assessed, of all included studies. AOTA staff and the EBP Project consultant reviewed the evidence table for quality control.

We assessed the risk of bias of individual studies using the methods described by Higgins, Altman, and Sterne (2011; see Supplemental Table 3, online). Our method for assessing the risk of bias of systematic reviews was based on the system developed by Shea et al. (2007; see Supplemental Table 4, online). Again, disagreements were resolved through consensus.

Data Synthesis

Given the heterogeneity of the included studies, we used a qualitative approach to data synthesis. Studies were examined for similarities across participants, settings, interventions, and outcomes and were grouped into themes. The strength of the evidence for each theme was appraised using an adaptation of the system proposed by the U.S. Preventive Services Task Force (2016):

Risk-of-bias appraisals were considered in designating strength of evidence.

Interventions That Address Behavior

Thirty-six studies included in this systematic review evaluated the effect of environment-based interventions on behaviors of people with AD and related major NCDs. These interventions are organized into five themes: unimodal sensory interventions, multisensory interventions, functional task object availability, specialized environments, and person-centered interventions.

Interventions That Address Perception

Insufficient evidence supports the use of optical interventions (e.g., tints, prisms) to decrease neuropsychiatric symptoms (Letts et al., 2011, Level I SR). Likewise, the evidence is limited for the benefit of printed or graphic signage, personal items such as photographs, and other environmental cues (e.g., colors, numbers) to assist people with AD and related major NCDs in way finding (Fleming & Purandare, 2010, Level I SR; Hodgkinson et al., 2007, Level I SR; Letts et al., 2011, Level I SR; Padilla, 2011a, Level I SR). Preliminary evidence suggests that a motorized belt providing vibrotactile cues to enable way finding may be effective for people with mild dementia (Grierson, Zelek, Lam, Black, & Carnahan, 2011, Level III).

A moderate net benefit was found for the use of visual cues in the environment. Black grids on the floor in front of doors and other unobtrusive safety measures (e.g., camouflaged doors, silent electronic locks, horizontal grids of black tape in front of exits, mirrors or cloths in front of exit doors) reduced attempts at exiting (Fleming & Purandare, 2010, Level I SR; Hodgkinson et al., 2007, Level I SR; Letts et al., 2011, Level I SR; Padilla, 2011a, Level I SR). A moderate net benefit was also found for the use of environmental design to reduce disorientation and promote engagement in people with AD and related major NCDs. Making an important amenity such as the toilet easily visible, using L-shaped halls rather than straight corridors, and placing posters and murals on walls were found to reduce disorientation and promote engagement (Fleming & Purandare, 2010, Level I SR; Letts et al., 2011, Level I SR).

Interventions That Address Falls

The evidence is insufficient to fully support the use of wander gardens for fall reduction. Preliminary results suggest that unrestricted daytime access to a wander garden decreased falls and antidepressant and antipsychotic medication use for dementia unit residents, especially those who accessed the garden frequently (Detweiler, Murphy, Kim, Myers, & Ashai, 2009, Level II). Although insufficient evidence indicates that environmental modification alone reduces falls, preliminary results suggest a positive effect when used as part of a multifaceted approach together with exercise and staff-directed, disciplinary interventions (Jensen & Padilla, 2011, Level I SR).

Strong evidence supports the use of night monitoring systems (e.g., bed exit alarms, alarm systems, tracking devices, automatic nightlights, bracelets with teleassistance) to reduce the incidence of falls and unattended exits at home (Rowe et al., 2009, Level I; Tchalla et al., 2013, Level I RCT). However, monitoring systems (bed exit sensors, bathroom and bedroom exit monitors) did not lead to a significant reduction in falls or injuries in a nursing home (Holmes et al., 2007, Level II). In fact, a decrease in the number of falls and fallers in a residential facility appeared more directly related to the removal of bed exit and chair alarms (Bressler, Redfern, & Brown, 2011, Level III).

Limited evidence suggests that the use of music to reduce falls is effective. Six hours of daily music exposure (classical, relaxation, and generationally appropriate) in a facility dining room did not lead to any statistically significant differences in falls per resident (Gill & Englert, 2013, Level III). However, noise reduction and temporally appropriate (i.e., stimulating, upbeat music in the morning and calming, soothing music in the afternoon), controlled background music in a nursing facility reduced accidents and injuries (Mercado & Mercado, 2006, Level III).

Implications for Practice

Strong or moderate evidence supports the following environment-based interventions, and therefore we recommend that occupational therapy practitioners routinely use them in practice:

Weak, conflicting, or insufficient evidence was found that the following interventions are effective for the listed outcome, and therefore we recommend that these interventions be used selectively on a case-by-case basis, heavily considering professional judgment and client preferences:

At least fair evidence was found that ambient music was ineffective in reducing falls, and therefore we recommend that occupational therapy practitioners not use this intervention in practice if the desired outcome is fall reduction.

Implications for Education

Interventions supported by strong evidence should be part of entry-level professional education. Students must have a comprehensive understanding of AD and related major NCDs, including the client factors that can be restored or maintained (e.g., strength, endurance) and those for which compensation is appropriate (e.g., memory). The concept of environment as intervention should be emphasized, with a focus on environmental adaptations in various settings, especially the home. Students should be prepared with skills to function as members of interprofessional or multidisciplinary teams to effectively collaborate in the provision of the multifactorial interventions people with AD and related major NCDs need and to advocate for policies that promote best practices in care in the home.

Implications for Research

More studies, especially those that can provide higher levels of evidence such as RCTs and systematic reviews, are needed to strengthen the available evidence for interventions that are occupation based rather than based on isolated sensory inputs. Increased homogeneity of participants (e.g., grouping participants by stage or severity of AD) is needed to more specifically determine the effectiveness of interventions. As aging in place becomes a wider goal, more studies conducted in the home setting will be needed.