Introduction

Delirium is a serious neurocognitive syndrome characterized by a sudden and fluctuating disturbance in an individual’s cognition, attention, and awareness [1]. Its diagnosis “requires evidence of an underlying organic cause” [2] (p. 1) which can involve any stressor (e.g., metabolic imbalance, infection) that disrupts the homeostasis of an individual with already diminished physiological reserves [1,2]. Although delirium can present at any age during the onset of an 1) acute illness, 2) acute exacerbation of a chronic condition, or 3) injury, it typically occurs in older people (age 65+) [3].

Although few studies have examined the prevalence of delirium at home in the community, studies estimate it ranges from .5% to 34.5% in the general non-hospital population aged 65+ with higher prevalence rates with increasing age [4]. For example, one study found delirium to be present in 17% of community-dwellers aged 85 and older increasing proportionally with age to 39% in those aged 95 and older [5]. Consequently, informal caregivers (i.e., any family member, friend, neighbor, or volunteer who provides informal, unpaid care at home; hereafter, referred to as caregivers) need to be able to recognize its onset at home in the community. Doing so will allow caregivers to seek medical attention from a primary care provider, which may prevent hospital admission and the worsening of delirium.

In the hospital setting, delirium has been found in 10%-30% of older patients upon admission to the emergency department [1], 20 to 23% of older medical inpatients [6,7], up to 50% of older post-operative patients, and 80% of older intensive care patients [8]. Delirium is regarded as reversable when the underlying cause can be resolved [3]. However, because of delirium’s protracted nature, when it is diagnosed in hospital, it usually continues after discharge– 36% of older patients have delirium at the time of hospital discharge [9]. The probability of full recovery is only 4% at 4 weeks and 27% at 24 weeks post-discharge [10]. Consequently, the caregivers of patients discharged with delirium require information on non-pharmacological interventions, such as promoting physical activity and reducing environmental noise, which are needed to promote recovery at home following hospitalization. Yet, many caregivers recognize their lack of knowledge in managing delirium and they find caring for someone with delirium to be very challenging [11].

Even when an older person’s delirium resolves during hospitalization, they remain at risk of experiencing a recurrence after discharge [12]. Because delirium can manifest as decreased psychomotor activity (e.g., listlessness, sleepiness), increased psychomotor activity (e.g., restlessness, agitation) or mixed psychomotor activity (e.g., alternating between listlessness and restlessness) [13], it can be difficult for caregivers to identify and/or manage. For example, when an older person is lethargic and listless, a caregiver may fail to recognize delirium and not seek medical help, thereby putting the older person at risk of experiencing delirium-related complications. Delirium in the post-discharge period is associated with serious complications including functional disability, loss of independence [8], hospital readmission, and death [10]. Indeed, people who manifest their delirium through decreased psychomotor activity have worse outcomes than those who manifest their delirium through increased psychomotor activity–likely due to delayed detection [14]. Caregivers may interpret excessive sleepiness as a person’s need for sleep and inadvertently encourage bed rest. Because ambulation and regulation of the sleep-wake cycle are interventions that promote recovery of delirium and mitigate its negative effects [3], encouraging bed rest may precipitate a new delirium or worsen an existing delirium.

While prior reviews have established the effectiveness of delirium detection [15–17] and/or management [18–20] interventions in improving patient outcomes, most reviews were limited to the hospital setting and did not extend into patients’ homes during the post-discharge period [16–20]. We found only four reviews that included studies conducted with the caregivers of older adults at home. A review by Zhou and colleagues (2023) focused solely on the diagnostic accuracy of tools to detect delirium and did not describe if and how caregivers were taught to use the tool [21], and a 2015 review led by Carbone excluded studies that focused only on the detection of delirium [22]. A review by Lee’s team (2023) described educational interventions for managing delirium but provided a high level, thematic interpretation of the interventions and did not describe their characteristics [23]. Only one review (Bull et al, 2016) attempted to describe the intervention under examination but only addressed dose (e.g., duration, frequency) [15]; moreover, that review was limited to studies examining the effects of educational interventions with experimental, quasi-experimental, and comparative designs. Most studies with these types of designs, particularly in the testing of non-pharmacological interventions, do not adequately describe the interventions being tested [24,25]. It has been our experience that detailed descriptions of interventions, when they do appear, tend to be published in protocols and other descriptive papers [26]. The lack of description of interventions in this clinical area thus likely limits intervention implementation and uptake [27]. For example, knowing whether an intervention initiated in hospital was in fact continued into the post-discharge period is critical to optimizing its use in the community.

Furthermore, the four available reviews restricted inclusion to studies published in English [15,21–23] or Chinese [21]. Delirium, however, is an important global issue as many countries are experiencing population aging [28]. There is likely untapped knowledge published in other languages that could enhance understanding of how to help caregivers detect and manage delirium. Yet, to the best of our knowledge, this information has not yet been synthesized to facilitate its widespread adoption.

Lastly, the four reviews that we found lacked comprehensiveness in their selection of databases. Bramer et al, 2017 recommends that, at a minimum, Medline and Embase should be searched along with Web of Science Core Collection, Google Scholar and specialized databases that are relevant to the topic [29]. In the case of searching for delirium detection and management interventions, CINAHL and PsycINFO should be included [29]. Likewise, any search in these databases should include a combination of index terms and keywords; only two reviews indicated that index terms and keywords were used to develop the search strategy [15,21].

This proposed scoping review will differ from prior reviews in several ways. First, the review will not be limited to only the hospital setting and will include interventions initiated in the hospital and extended into the home. Second, this review will also include studies that initiated the interventions in the non-hospital setting. Third, unlike prior reviews, this review will provide comprehensive, in-depth descriptions of the interventions. Fourth, the search strategy will undergo peer review and will be as comprehensive as possible. Lastly, there will be no limitations on the language of papers.

The proposed review addresses an immense gap in synthesized knowledge. In our preliminary search of PROSPERO, MEDLINE, Pilot and Feasibility Studies, the Cochrane Database of Systematic Reviews, Epistemonikos, and the JBI Evidence Synthesis, we identified no current or underway systematic or scoping reviews on this specific topic. Furthermore, this search identified four unique articles that were not included in the four prior reviews that included studies conducted with the caregivers of older adults at home [15,21–23]. The objective of this proposed scoping review is to identify and map the available evidence on interventions that aim to help caregivers identify and/or manage delirium in an older person at home.

Materials and methods

The proposed scoping review will be conducted in accordance with the JBI methodology for scoping reviews [30] and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) [31]. A scoping review is “a type of evidence synthesis that aims to systematically identify and map the breadth of evidence available on a particular topic, field, concept, or issue, often irrespective of source (i.e., primary research, reviews, non-empirical evidence) within or across particular contexts” (page 1) [32]. Because we could not locate any existing reviews that provide an in-depth description of interventions that aim to help caregivers identify and/or manage delirium in an older person at home, we determined that a scoping review to identify and map this body of literature, rather than a systematic review, was most appropriate to meet our review objective. The protocol is registered with AsPredicted, Registration #160678 (https://aspredicted.org/WNW_QFS).

Supporting information

Acknowledgments

The authors would like to thank York University undergraduate students Shannon Gordon and Madison Clancy for their help in reviewing the literature.