Disrupted sleep and associated factors in Australian dementia caregivers: a cross-sectional study

Dementia is an inclusive term used to describe a number of neurological conditions resulting in cognitive impairment and can include Alzheimer’s Disease (senile dementia), frontotemporal dementia, vascular dementia, Lewy Body dementia, Korsakoff syndrome (alcohol related brain injury) and younger onset dementia [1‐3]. Globally, the number of individuals with a formal dementia diagnosis, rose from 20.2 million in 1990 to 43.8 million in 2016 [4]. A further 9.9 million new cases of dementia worldwide are predicted each year [5] as populations around the globe continue to live longer [6]. These figures could be very much under estimated as it is widely accepted that between 50 and 80% of people affected have no formal dementia diagnosis [7]. This growing epidemic effects not only the individuals living with dementia, but also their families caring for them, the communities they live in and the health care systems they rely upon.

Family or friends are often key informal caregivers for people living with dementia [8, 9]. Globally, over 80 billion hours of informal care is provided to people living with dementia [5, 10]. Whilst providing this care can be highly rewarding, it has also been described as a chronic stressor with caregivers reporting low quality and quantity of sleep [11] and high levels of stress and depression [12]. In fact, sleep disruption is prevalent amongst dementia caregivers with over 90% of caregivers experiencing sleep disturbances [13].

The National Sleep Foundation recommend that older adults (≥65 years) require seven to 8 h sleep for optimal physical and psychological wellbeing [14]. Yet, numerous studies have illustrated that dementia caregivers sleep significantly less than that with estimates reporting most caregivers sleep less than 7 h per night [15]. Not only are caregivers sleeping less than they should, the sleep they do get is of significantly lower quality than their non-caregiver counterparts [11].

Poor sleep is associated with a myriad of negative physical and psychological outcomes including hypertension, obesity, mood disorders and dementia [16]. A disrupted sleep pattern is also recognised as a significant factor in predicting caregiver strain [17, 18] and perhaps more importantly, in predicting placing an individual into long term care [19]. Enabling people living with dementia to stay at home, rather than transfer to long-term care is the optimal outcome for many families. However, this cannot be to the detriment of the caregiver’s own physical and/or psychological wellbeing. Therefore, in order to support the person living with dementia (PLWD) to remain in the community, maintaining caregiver health is vital. Given the pivotal role sleep has in a myriad of physiological processes, it is essential to optimise and preserve caregivers sleep.

Despite the important role sleep plays in dementia caregiver health, it remains an understudied population, particularly within the Australian context. In fact, a recent report by Carers Australia (2019) identified no Australian studies on sleep disruption in dementia caregivers. Only sixteen international studies were identified which subjectively measured sleep in the dementia caregivers population, with the majority of studies not reporting on the causes or consequences of disturbed sleep [15].

In order to address this paucity of Australian data, the purpose of this study was to elucidate the sleep characteristics and disturbances of Australian caregivers of PLWD. Furthermore, this study will determine whether there is a relationship between sleep and psychological wellbeing among caregivers of community-dwelling people living with dementia. Lastly, we will aim to identify significant predictors of poor sleep, which in turn could offer a therapeutic target of poor sleep in dementia caregivers.

A recent Australian report highlighted a significant gap in the literature around Australian caregivers of a PLWD [15]. Our study provides a comprehensive overview of Australian dementia caregivers sleep characteristics, associations between psychological wellbeing and sleep and highlights a predictive role for stress in sleep quality. All previous international studies identified an average PSQI >/ 5 in dementia caregiver studies [15] highlighting the prevalence of the issue. As expected, and consistent with previous studies [13], Australian caregivers of PLWD have a high prevalence of poor sleep with 94% of participants classified as poor sleepers. The PSQI global score (9.12 ± 3.7) was higher than those found in some dementia caregiver studies [24, 25] but comparable with others [13]. The PSQI sub-components which greatest contributed to the overall score were sleep latency (time taken to fall asleep), sleep quality (overall subjective quality) and sleep disturbances. Sleep latency and sleep disturbances have previously been identified as the most common contributors to sleep quality in caregivers of PLWD in a recent systematic review [11]. Given the dearth of Australian specific data, this study identified important depth of detail around caregiver’s sleep characteristics. 85% of caregivers took longer than the recommended 15 min to fall asleep, only 20% of caregivers slept more than 7 h, 72% of caregivers had sleep efficiency lower that the recommended 85 and 55% of caregivers used sleep aiding medication in the previous month. Taken together, these descriptive findings present a novel and ominous overview of the poor sleep health conditions that Australian dementia caregivers experience.

Caregivers of community dwelling people living with dementia reported poor sleep quality and high levels of depression, anxiety and stress. This study found that poor sleep was correlated with subjective feelings of depression, anxiety and stress, which were in keeping with previous literature around caregiving and psychological distress. More than half of the caregivers surveyed reported symptoms of depression and stress (56 and 58% respectively) and 39% reported anxiety. These findings are in keeping with that of a recent study of dementia caregivers in rural Victoria, where 49% of caregivers reported depression or stress and 26% reported anxiety [12].

Previous work has identified an association between depression and poor sleep among dementia caregivers [26, 27]. Reduced quality of sleep and depression are higher among caregivers of people living with dementia [17]. Furthermore, caregivers of people living with dementia, who were also depressed, experience a greater variation in sleep patterns [17].

This study reveals sleep scores were significantly associated with measures of depression, anxiety and stress. These findings illustrate the interplay between sleep quality and quantity and psychological wellbeing in caregivers providing care for an individual living with dementia. Further exploration of predictive factors in caregivers sleep quality identified stress as a key predictor of poor overall sleep quality whilst adjusting for age, gender, comorbidities and length of care. This is a novel finding and represents a potential therapeutic target to improve sleep quality in dementia caregivers.

Despite the high prevalence of self-identified poor sleep, overnight respite was only used by 8% of participants, which is in keeping with previous research that cites 87% of Australian caregivers have never used respite services [28]. Access to respite care remains one of the major means of easing caregiver burden and is frequently identified as needed by caregivers, yet remains underutilised. Whilst a high proportion of dementia caregivers report a need for respite services, there is insufficient awareness of and access to respite services for caregivers [29]. Respite service availability can be invaluable with caregivers reporting lower stress levels and improved health after use [30]. Sleep disturbances have also been shown to be partially reversed for caregivers during periods of respite care [31], perhaps due to reversal of hyper stressed state. Respite services have been cited as an important measure to allow caregivers time to attend to their own health, imperative to supporting the caregiver to continue in providing care for their loved one [30].

A recent Australian parliamentary inquiry into sleep health identified sleep as a foundation of positive health and wellbeing, alongside diet and exercise [32]. Furthermore, the report urged government to prioritise sleep health as a national priority given its pivotal role in maintaining health. It is clear that caregivers of PLWD have sub-optimal sleep which is associated with poorer psychological wellbeing and potential increased risk of developing chronic health conditions such as diabetes and cardiovascular disease [16]. Interestingly, cardiovascular disease and endocrine disease such as diabetes were the most prevalent comorbidities in our study population. Previous studies have also identified high blood pressure, diabetes and arthritis as the most prevalent chronic disease in the dementia caregiver group which is in keeping with our findings [33].

Managing sleep and its associated mediators will have direct impact on both the caregiver’s own health as well as the caregiver/ care recipient relationship. It is imperative to provide educational support around sleep, consider practical interventions such as overnight respite and to address stress management interventions for caregivers, in turn, reinstating and preserving sleep of this critical population of informal caregivers.

Sleep problems are widespread within the population of dementia caregivers. Given that the majority of people living with dementia are reliant on family caregivers, minimising health and psychological impact on caregivers should be of major concern. Furthermore, sleep quality is correlated with emotional distress in dementia caregivers, so improving the sleep of caregivers may in turn improve their psychological wellbeing. Conversely, stress is a significant predictor of poor sleep, so managing stress may have a positive impact on sleep.

Dementia caregivers are often older, with co-existing morbidities and high levels of psychological distress. With prolonged caregiving and the progression of dementia of the care recipient, there is the potential for a concurrent decline in the caregivers mental and physical health. In order to support the caregiver in their role, it is of the upmost importance that we promote and maximises their health and wellbeing. By managing and minimising the negative factors associated with caregiving, we can enhance caregiving satisfaction and gratification. In turn, this can ensure optimal caregiver-care recipient relationship, supporting the person living with dementia to remain at home as long as possible.