Association Between Cohabitation Status and Sleep Quality in Families of Persons With Dementia in Korea: A Cross-sectional Study

Article information

J Prev Med Public Health. 2021;54(5):317-329
Publication date (electronic) : 2021 August 14
doi : https://doi.org/10.3961/jpmph.21.077
1Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea
2Institute of Health Services Research, Yonsei University, Seoul, Korea
3Department of Public Health, Graduate School, Yonsei University, Seoul, Korea
Corresponding author: Eun-Cheol Park Department of Preventive Medicine Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea E-mail: ecpark@yuhs.ac
Received 2021 February 10; Accepted 2021 June 25.

Abstract

Objectives

The aim of this study was to identify the association between cohabitation status and sleep quality in family members of people with dementia (PwDs).

Methods

Data of 190 365 participants aged ≥19 years from the 2018 Korea Community Health Survey were analyzed. Participants were categorized according to their cohabitation status with PwDs. Multiple logistic regression and ordinal logistic regression analyses were performed to evaluate the relationship between the cohabitation status of PwDs’ relatives and sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI) and PSQI subscales.

Results

Compared to participants without PwDs in their families, both cohabitation and non-cohabitation with PwDs were associated with poor sleep quality (cohabitation, male: odds ratio [OR],1.28; 95% confidence interval [CI], 1.08 to 1.52; female: OR, 1.40; 95% CI, 1.20 to 1.64; non-cohabitation, male: OR, 1.14; 95% CI, 1.05 to 1.24; female: OR, 1.23; 95% CI, 1.14 to 1.33). In a subgroup analysis, non-cohabiting family members showed the highest odds of experiencing poor sleep quality when the PwD lived alone (male: OR, 1.48; 95% CI, 1.14 to 1.91; female: OR, 1.58; 95% CI, 1.24 to 2.01). Cohabiting male and female participants had higher odds of poor subjective sleep quality and use of sleeping medications than non-cohabiting male and female participants, respectively.

Conclusions

The residence of PwDs and cohabitation status may contribute to poor sleep quality among PwDs’ family members. The circumstances faced by cohabiting and non-cohabiting family members should be considered when evaluating sleep quality in family members of PwDs, and appropriate interventions may be needed to improve sleep quality in both cohabiting and non-cohabiting family members.

INTRODUCTION

Approximately 50 million people have dementia worldwide, and nearly 10 million new cases occur every year [1]. As no treatment to date is available to cure dementia or to alter its progressive course, dementia is one of the representative diseases that cause disabling and burdensome health issues [2]. A loved one’s diagnosis of dementia can be one of the saddest events in a person’s life and comes with special challenges. Since a dementia diagnosis is confirmed well after the onset of symptoms, the family of a person with dementia (PwD) may not be able to understand the PwD’s behavior before a diagnosis is established [3]. Because PwDs experience relentless cognitive deterioration and corresponding behavioral changes, they require the support of caregivers for many hours of the day; moreover, family members may feel confused about their newfound roles as caregivers post-diagnosis. Although approximately 90% of PwDs are institutionalized before their death, approximately 84% of PwDs worldwide live at home until their family cannot care for them [4,5].

Family members of PwDs may not only experience physical burdens, but also psychological or emotional burdens such as guilt arising from the belief that it is their responsibility to care for their relative [6,7]. Thus, being a caregiver may be associated with exposure to stress, a decrease in subjective physical health and social networking, and an increased risk of depression and mortality [8-10].

Another problem of long-term care for dementia patients is sleep disturbances in their family members. Sleep disturbances are associated with a high risk of cardiovascular disease, depressive symptoms, and all-cause mortality [11,12]. A previous study reported that approximately two-thirds of caregivers for PwDs experienced sleep disturbances [13,14]; and most studies on sleep quality in family members of PwDs have focused on family caregivers living with PwDs. However, family members may feel guilty and lonely even if they do not live with a PwD [15], and strong negative and weak positive emotions can affect sleep quality in non-cohabiting family members [16].

Although the existence of dementia patients in the family may adversely affect the sleep quality of family members, no study has yet examined sleep quality according to the cohabitation status of family members of PwDs. Therefore, this study investigated the association between the cohabitation status of family members of PwDs and sleep quality based on the quantitative and subjective aspects of sleep using the Korean version of the Pittsburgh Sleep Quality Index (PSQI-K) [17].

METHODS

Study Population and Data

The study data were obtained from the Korea Community Health Survey (KCHS) in 2018. The KCHS is a nationwide survey of public health and health behaviors that has been administered by the Korea Disease Control and Prevention Agency (formerly the Korea Centers for Disease Control and Prevention) since 2008. The dataset used in this study is publicly available on the KCHS’s official website (https://chs.kdca.go.kr/chs/). Stratified cluster sampling methods were used to select sample areas, and systematic sampling methods were used to select sample households in the KCHS. A trained interviewer personally visited the households selected for the sample and conducted a survey with adults aged ≥19 years living within these households. The questionnaire comprised approximately 201 items in 21 areas and included questions on demographic characteristics, subjective health levels, health-related behaviors, and chronic disease history.

In total, 228 340 people participated in the 2018 KCHS. Participants who did not identify their cohabitation status with a PwD or had missing data on covariates were excluded from this study. People from single-person households whose sleep quality was unlikely to be affected by other family members and participants with dementia were also excluded. Finally, 190 365 participants were included.

Variables

The main dependent variable was sleep quality, which was measured using the PSQI-K, a tool for evaluating sleep quality and quantity during the past month. The Pittsburgh Sleep Quality Index (PSQI) is the gold standard screening tool for evaluating sleep dysfunction and has been validated in both clinical and non-clinical samples [18,19]. The PSQI-K also showed high sensitivity and specificity and was previously validated [17]. The PSQI-K comprises 18 questions using a 4-point Likert scale (0-3) that are categorized into 7 subscales for sleep and daytime functions: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medication, and daytime dysfunction. The questions on the PSQI-K and the detailed method of calculating the scores for the 7 components based on each question are presented in Supplemental Material 1. The global PSQI score is the sum of the scores for each subscale and ranges from 0 to 21. In this study, a score of ≤5 indicated good sleep quality, and a score of >5 indicated poor sleep quality [20]. Previous research validated the use of a cut-off point of 5 in the PSQI-K [21,22]. Furthermore, the internal reliability of the PSQI-K used in this study was examined using Cronbach’s alpha coefficient for internal consistency. Cronbach’s alpha was 0.75 for the total PSQI-K score, indicating high reliability.

The independent variable was the cohabitation status of family members of PwDs. Participants were classified into the following 3 groups depending on whether they had a PwD in their family and whether they lived with the PwD: family members without a PwD (reference group), non-cohabiting family members of a PwD, and family members cohabiting with a PwD. Furthermore, the non-cohabiting family members were subdivided based on the residence of the PwD.

This study included demographic and socioeconomic characteristics (age, marital status, the number of family members and cohabiting generations, educational level, income level, and employment status), the number of chronic diseases (hypertension and diabetes mellitus), depressive symptoms, and health-related behaviors (smoking status, alcohol consumption, and physical activity) as covariates. Depressive symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ-9), and categorized as either present (PHQ-9 score ≥10) or absent (PHQ-9 score <10) [23]. Participants with high physical activity levels were defined as those who walked ≥30 min/d for ≥5 d/wk.

Statistical Analysis

All analyses were conducted separately for male and female in consideration of the factors influencing sex differences in sleep quality [22,24]. We used the chi-square test to assess differences in the frequencies and proportions of categorical variables. Multiple logistic regression analysis was performed to examine the association between cohabitation status and sleep quality after adjusting for covariates. Subgroup analyses were conducted to evaluate the association of the residence of PwDs with sleep quality in their family members, and then the data were analyzed by cohabitation status using multiple logistic regression analyses. Finally, for the dependent subgroup analyses, multivariable ordinal logistic regression analysis was conducted to investigate the association between cohabitation status and the PSQI components. The response variables for dependent subgroup analyses were categorical variables that had 4 possible levels with an ordinal nature (e.g., subjective sleep quality: very good, fairly good, fairly bad, and very bad) [25]. All statistical analyses were performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA), and a weighted logistic regression procedure was used to account for the complex and stratified sampling design of the KCHS. Two-sided p-values <0.05 were considered to indicate statistical significance.

Ethics Statement

Since the KCHS is a survey conducted by the government for the public welfare, ethics approval for the KCHS was waived by the Bioethics and Safety Act, 2015.

RESULTS

The participants’ general characteristics are described in Table 1. Of the 190 365 participants, 89 197 (46.9%) were male. 30 814 (34.5%) of the male participants and 45 496 (45.0%) of the female participants experienced poor sleep quality. Among the male family members of a PwD, 1174 lived with the PwD and 4034 lived separately from the PwD. Moreover, 526 (44.8%) cohabiting male family members of PwDs and 1497 (37.1%) non-cohabiting family members experienced poor sleep quality. In contrast, 736 (56.5%) of the 1302 cohabiting female family members and 2220 (48.3%) of the 4596 non-cohabiting female family members reported poor sleep quality. Table 2 outlines the general characteristics of participants with cohabitation status. Overall, family members living with PwDs were more likely to be divorced, have ≥5 family members, live with ≥2 generations, have low income, be unemployed, or have depression or chronic disease. In contrast, non-cohabiting family members of PwDs were more likely to have a higher family income and education level.

General characteristics of the study subjects

Demographic characteristics of participants according to cohabitation status

Table 3 presents the factors associated with poor sleep quality. After adjusting for covariates, cohabiting family members of PwDs were more likely to have poor sleep quality than members of families without a PwD. These results were significant in both male (odds ratio [OR],1.28; 95% confidence interval [CI], 1.08 to 1.52) and female (OR, 1.40; 95% CI, 1.20 to 1.64). Furthermore, non-cohabiting family members of PwDs also showed higher odds of poor sleep quality than family members without a PwD (male: OR, 1.14; 95% CI, 1.05 to 1.24; female: OR, 1.23; 95% CI, 1.14 to 1.33). In subgroup analyses, a very low family income level and the presence of depressive symptoms were associated with poor sleep quality in both sexes among noncohabiting family members of PwDs. A low-level of education was associated with poor sleep quality in male participants (Supplemental Material 2). Among cohabiting family members with PwDs, an age of 50-59 years, a very low family income level, a low-level of education, and depressive symptoms were associated with poor sleep quality in both sexes. Divorced male participants were also more likely to have poor sleep quality than married male participants (Supplemental Material 3).

Factors associated with poor sleep quality

Figure 1 presents the analysis of sleep quality in family members of PwDs according to the PwD’s residence. Among noncohabiting relatives, the odds of having poor sleep quality significantly increased when the PwD lived alone (male: OR, 1.48; 95% CI, 1.14 to 1.91; female: OR, 1.58; 95% CI, 1.24 to 2.01) or with other family members (male: OR, 1.16; 95% CI, 1.01 to 1.35; female: OR, 1.34; 95% CI, 1.17 to 1.54). However, when the PwD lived in a nursing facility, the sleep quality of non-cohabiting family members did not differ from that of family members without a PwD.

Figure. 1.

Association of cohabitation status and residence of a person with dementia (PwD) with sleep quality in family members (A: male B: female) of a PwD. pt., patients; aOR, adjusted odds ratio; CI, confidence interval.

Figure 2 shows the results of multivariable ordinal logistic regression analysis of the association between the cohabitation status of family members of PwDs and PSQI subscales. In female participants, the presence of a PwD in the family regardless of cohabitation status was significantly associated with poor subjective sleep quality, sleep disturbances, and daytime dysfunction. In male participants, the presence of a PwD in the family regardless of cohabitation status was associated with short sleep duration, poor sleep efficiency, sleep disturbances, and daytime dysfunction. Additionally, cohabiting male participants had a higher probability of poor subjective sleep quality (OR, 1.32; 95% CI, 1.15 to 1.51) and cohabiting female participants were more likely to use sleeping medications (OR, 1.36; 95% CI, 1.06 to 1.74) and experience daytime dysfunction (OR, 1.13; 95% CI, 1.00 to 1.27) than non-cohabiting male and female relatives of PwDs.

Figure. 2.

Association between the cohabitation status of family members of a person with dementia (PwD) and the Pittsburgh Sleep Quality Index subscales using multivariable ordinal logistic regression. (A) Family members without a PwD as the reference group. (B) Non-cohabiting family members of a PwD as the reference group. *p<0.05.

DISCUSSION

This study revealed that family members living with PwDs had significantly higher odds of experiencing poor sleep quality, similar to the results of previous studies [13]. Among family members living with PwDs, a very low family income level and low-level of education were associated with poor sleep quality in both male and female participants. As in previous studies, people living with PwDs were more likely to have depression or chronic diseases than their counterparts [13].

In 2019, more than 16 million family members and other unpaid caregivers provided about 18.6 billion hours of care to individuals with dementia, worth nearly US$244 billion [26]. Moreover, the caregivers’ burden is known to be higher in those who care for individuals with dementia than in those who care for individuals with other chronic diseases [27]. Individuals living with a PwD may face various challenges in caring for the PwD every day and may need to make care-related decisions [28]. However, caregivers are often unprepared for their roles and responsibilities, are not very familiar with treatment options, are uncertain about patient preferences, and often do not get expert support in making decisions [28,29]. In this study, a low-level of education may have been related to inexperience in responding to unpredictable situations in caring for dementia patients, which may have been linked to poor sleep quality. Our findings demonstrated the need to develop and to apply appropriate interventions such as education for caring for dementia patients, as well as financial support, to reduce the caregiving burden on family members living with a PwD to improve their sleep quality.

Interestingly, even family members not living with a PwD were more likely to have poor sleep quality than family members without a PwD. Factors associated with poor sleep quality among the non-cohabiting group were a very low family income level and presence of depressive symptoms in both sexes and a low-level of education in male participants. These results imply that a low economic level—that is, the economic burden—in non-cohabiting family members of PwDs, as with cohabiting family members, may adversely affect sleep quality [30]. In addition, low-levels of education, which were associated with poor sleep quality in male participants, are inseparable from the economic burden. This can be explained by the traditional Korean gender role for men, who are primarily responsible for household finances [31]. Depressive symptoms were also found to be highly associated with poor sleep quality in cohabitating and non-cohabitating family members, so they are essential to consider when planning a management policy for the families of PwDs [30,31].

Furthermore, the results of subgroup analyses based on the PwDs’ residence showed that non-cohabiting family members of a PwD had significantly higher odds of having poor sleep quality when the PwD lived alone or with other family members. When the PwD lived alone, the probability of a family member experiencing poor sleep quality was the most prominent, which was presumably due to guilt and anxiety about not caring for the PwD directly [32]. Previous research reported that approximately 65% of caregivers for PwDs express feelings of guilt [33,34] and caregiving–related distress predicted sleep problems [35]. In contrast, when the PwD lived in a nursing facility, there was no significant difference in sleep quality between family members of a PwD and those without a PwD. This may be explained by the results of a previous study, which reported that family members of PwDs felt relief, but also had a troubled conscience, when placing a relative with dementia in a nursing home [36]. In other words, family members who relocated the PwD to a nursing facility showed ambivalence, and it can be assumed that this was reflected in sleep quality. These results imply that non-cohabiting family members of a PwD, especially those of a PwD who lives alone, may require appropriate interventions that consider the differences in their circumstances such as the “New Orange Plan,” a comprehensive support system for PwDs via home-visit nurses in Japan [32].

Another notable finding was that cohabiting male and female relatives of a PwD had a higher probability of poor subjective sleep quality and use of sleeping medications than non-cohabiting male and female family members of a PwD, respectively. These results indicate that when investigating the cause of poor sleep quality and developing appropriate interventions in family members of PwDs, researchers should consider the difference between male and female family members.

Our study has some limitations. First, it was not possible to identify the exact roles of the family members regarding caregiving and the burden of caregivers, since there were no survey data on caring for home-dwelling persons with dementia. The perceived health of caregivers varies depending on the level of the caregivers’ burden, and this burden is not the same for all family members [37]. Therefore, the sleep quality of family members can be affected by the relationship with the PwD and the role of other family members. Second, it was not possible to consider the type and severity of dementia, because the KCHS did not contain this information. The caregiving burden and quality of life of caregivers may vary according to the type of dementia, such as frontotemporal dementia or Alzheimer’s disease, as well as the severity or symptoms of dementia; thus, further studies are needed to consider these factors [38]. Third, the duration of caregiving may affect caregivers’ sleep quality, although we were unable to consider these factors in our study. Fourth, ordinal logistic regression was used to analyze the association between cohabitation status and the PSQI subscales because the items corresponding to each score were not uniform and previous studies were conducted through ordinal logistic regression [25,39], but there is a great deal of controversy about whether to use an ordinal model or a continuous model with respect to Likert-scale measurements [40]. Finally, the study’s cross-sectional nature did not allow us to clearly identify the direction of the relationship between cohabitation status and sleep quality. Further longitudinal studies are required to establish a causal relationship.

Despite these limitations, our research has notable strengths. First, this study was based on nationwide representative data collected from 253 community health centers and 35 universities. Second, to the best of our knowledge, this is the first study to evaluate the association between the cohabitation status of family members of PwDs and sleep quality measured by the PSQI, a suitable tool for measuring sleep quality in the general population. Our research implies that appropriate interventions for improving sleep quality in family members of PwDs need to be developed and applied, regardless of whether family members live with a PwD.

In conclusion, our research suggests that cohabitation status, the place where the PwD lives, and financial status can all affect sleep quality. Therefore, it is necessary to understand the circumstances influencing cohabiting and non-cohabiting family members when evaluating sleep quality in family members of PwDs, and appropriate interventions may be needed to improve sleep quality in both cohabiting and non-cohabiting family members.

SUPPLEMENTAL MATERIALS

Supplemental materials are available at https://doi.org/10.3961/jpmph.21.077.

Supplemental Material 1

Result of Primary component analysis

Supplemental Material 2

Result of Primary component analysis

Supplemental Material 3

Result of Primary component analysis

Notes

CONFLICT OF INTEREST

The authors have no conflicts of interest associated with the material presented in this paper.

FUNDING

None.

Acknowledgements

We would like to thank the Korea Disease Control and Prevention Agency (KDCA), which provided the data based on a nationwide survey.

Notes

AUTHOR CONTRIBUTIONS

Conceptualization: SHK, ECP. Data curation: SHK, MP, SHJ. Formal analysis: SHK. Funding acquisition: None. Methodology: SHK, ECP. Visualization: SHK, MP, SHJ. Writing – original draft: SHK. Writing – review & editing: MP, SHJ, SIJ, ECP.

References

1. World Health Organization. Dementia. [cited 2021 Jan 14]. Available from: https://www.who.int/news-room/fact-sheets/detail/dementia.
2. Cova I, Markova A, Campini I, Grande G, Mariani C, Pomati S. Worldwide trends in the prevalence of dementia. J Neurol Sci 2017;379:259–260.
3. Speechly CM, Bridges-Webb C, Passmore E. The pathway to dementia diagnosis. Med J Aust 2008;189(9):487–489.
4. Walter E, Pinquart M. How effective are dementia caregiver interventions? An updated comprehensive meta-analysis. Gerontologist 2020;60(8):609–619.
5. Wimo A. Establishing and funding long term care infrastructure. In : In: the 33rd International Conference of Alzheimer’s Disease International; 2018 July 26-29; Chicago, USA; 2018. 26–29.
6. Prunty MM, Foli KJ. Guilt experienced by caregivers to individuals with dementia: a concept analysis. Int J Older People Nurs 2019;14(2):e12227.
7. Gallego-Alberto L, Losada A, Cabrera I, Romero-Moreno R, Pérez-Miguel A, Pedroso-Chaparro MDS, et al. “I feel guilty”. Exploring guilt-related dynamics in family caregivers of people with dementia. Clin Gerontol 2020. 1–10.
8. Almberg B, Grafström M, Krichbaum K, Winblad B. The interplay of institution and family caregiving: relations between patient hassles, nursing home hassles and caregivers’ burnout. Int J Geriatr Psychiatry 2000;15(10):931–939.
9. Schulz R, Beach SR. Caregiving as a risk factor for mortality: the Caregiver Health Effects Study. JAMA 1999;282(23):2215–2219.
10. Alzheimer’s Disease International. World Alzheimer report 2018. The state of the art of dementia research: new frontiers. 2018. [cited 2021 Jan 14]. Available from: https://www.alzint.org/u/WorldAlzheimerReport2018.pdf.
11. Yin J, Jin X, Shan Z, Li S, Huang H, Li P, et al. Relationship of sleep duration with all-cause mortality and cardiovascular events: a systematic review and dose-response meta-analysis of prospective cohort studies. J Am Heart Assoc 2017;6(9):e005947.
12. Fang H, Tu S, Sheng J, Shao A. Depression in sleep disturbance: a review on a bidirectional relationship, mechanisms and treatment. J Cell Mol Med 2019;23(4):2324–2332.
13. McCurry SM, Logsdon RG, Teri L, Vitiello MV. Sleep disturbances in caregivers of persons with dementia: contributing factors and treatment implications. Sleep Med Rev 2007;11(2):143–153.
14. Gao C, Chapagain NY, Scullin MK. Sleep duration and sleep quality in caregivers of patients with dementia: a systematic review and meta-analysis. JAMA Netw Open 2019;2(8):e199891.
15. Høgsnes L, Melin-Johansson C, Norbergh KG, Danielson E. The existential life situations of spouses of persons with dementia before and after relocating to a nursing home. Aging Ment Health 2014;18(2):152–160.
16. Baglioni C, Spiegelhalder K, Lombardo C, Riemann D. Sleep and emotions: a focus on insomnia. Sleep Med Rev 2010;14(4):227–238.
17. Sohn SI, Kim DH, Lee MY, Cho YW. The reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index. Sleep Breath 2012;16(3):803–812.
18. Buysse DJ, Reynolds CF 3rd, Monk TH, Hoch CC, Yeager AL, Kupfer DJ. Quantification of subjective sleep quality in healthy elderly men and women using the Pittsburgh Sleep Quality Index (PSQI). Sleep 1991;14(4):331–338.
19. Mollayeva T, Thurairajah P, Burton K, Mollayeva S, Shapiro CM, Colantonio A. The Pittsburgh sleep quality index as a screening tool for sleep dysfunction in clinical and non-clinical samples: a systematic review and meta-analysis. Sleep Med Rev 2016;25:52–73.
20. Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res 1989;28(2):193–213.
21. Choi H, Kim S, Kim B, Kim I. Psychometric properties of the Korean versions of three sleep evaluation questionnaires. Clin Nurs Res 2015;24(5):526–538.
22. Lee SY, Ju YJ, Lee JE, Kim YT, Hong SC, Choi YJ, et al. Factors associated with poor sleep quality in the Korean general population: providing information from the Korean version of the Pittsburgh Sleep Quality Index. J Affect Disord 2020;271:49–58.
23. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med 2001;16(9):606–613.
24. Chang AK, Choi J. Predictors of sleep quality among young adults in Korea: gender differences. Issues Ment Health Nurs 2016;37(12):918–928.
25. Habibi F, Mahdavi SB, Khaniabadi BM, Habibi ME, Gharavinia A, Baghaei A, et al. Sleep quality and associated factors in Iranian inflammatory bowel disease patients. J Res Med Sci 2019;24:59.
26. 2020 Alzheimer’s disease facts and figures. Alzheimers Dement 2020;16(3):391–460.
27. Schoenmakers B, Buntinx F, DeLepeleire J. Supporting the dementia family caregiver: the effect of home care intervention on general well-being. Aging Ment Health 2010;14(1):44–56.
28. Xie B, Champion JD, Kwak J, Fleischmann KR. Mobile health, information preferences, and surrogate decision-making preferences of family caregivers of people with dementia in rural hispanic communities: cross-sectional questionnaire study. J Med Internet Res 2018;20(12)e11682.
29. Gessert CE, Forbes S, Bern-Klug M. Planning end-of-life care for patients with dementia: roles of families and health professionals. Omega (Westport) 2000;42(4):273–291.
30. Peng HL, Lorenz RA, Chang YP. Factors associated with sleep in family caregivers of individuals with dementia. Perspect Psychiatr Care 2019;55(1):95–102.
31. Jang SI, Bae HC, Shin J, Jang SY, Hong S, Han KT, et al. Depression in the family of patients with dementia in Korea. Am J Alzheimers Dis Other Demen 2016;31(6):481–491.
32. Kitamura T, Tanimoto C, Oe S, Kitamura M, Hino S. Familial caregivers’ experiences with home-visit nursing for persons with dementia who live alone. Psychogeriatrics 2019;19(1):3–9.
33. Gonyea JG, Paris R, de Saxe Zerden L. Adult daughters and aging mothers: the role of guilt in the experience of caregiver burden. Aging Ment Health 2008;12(5):559–567.
34. Roach L, Laidlaw K, Gillanders D, Quinn K. Validation of the Caregiver Guilt Questionnaire (CGQ) in a sample of British dementia caregivers. Int Psychogeriatr 2013;25(12):2001–2010.
35. Wilson SJ, Padin AC, Birmingham DJ, Malarkey WB, Kiecolt-Glaser JK. When distress becomes somatic: dementia family caregivers’ distress and genetic vulnerability to pain and sleep problems. Gerontologist 2019;59(5):e451–e460.
36. Seiger Cronfalk B, Ternestedt BM, Norberg A. Being a close family member of a person with dementia living in a nursing home. J Clin Nurs 2017;26(21-22):3519–3528.
37. Andrén S, Elmståhl S. The relationship between caregiver burden, caregivers’ perceived health and their sense of coherence in caring for elders with dementia. J Clin Nurs 2008;17(6):790–799.
38. Riedijk SR, De Vugt ME, Duivenvoorden HJ, Niermeijer MF, Van Swieten JC, Verhey FR, et al. Caregiver burden, health-related quality of life and coping in dementia caregivers: a comparison of frontotemporal dementia and Alzheimer’s disease. Dement Geriatr Cogn Disord 2006;22(5-6):405–412.
39. Wang L, Qin P, Zhao Y, Duan S, Zhang Q, Liu Y, et al. Prevalence and risk factors of poor sleep quality among Inner Mongolia Medical University students: a cross-sectional survey. Psychiatry Res 2016;244:243–248.
40. Harpe SE. How to analyze Likert and other rating scale data. Curr Pharm Teach Learn 2015;7(6):836–850.

Article information Continued

Figure. 1.

Association of cohabitation status and residence of a person with dementia (PwD) with sleep quality in family members (A: male B: female) of a PwD. pt., patients; aOR, adjusted odds ratio; CI, confidence interval.

Figure. 2.

Association between the cohabitation status of family members of a person with dementia (PwD) and the Pittsburgh Sleep Quality Index subscales using multivariable ordinal logistic regression. (A) Family members without a PwD as the reference group. (B) Non-cohabiting family members of a PwD as the reference group. *p<0.05.

Table 1.

General characteristics of the study subjects

Characteristics Sleep quality
Male (n=89 197)
Female (n=101 168)
Total Poor (PSQI>5) Good (PSQI≤5) p-value Total Poor (PSQI>5) Good (PSQI≤5) p-value
Total (n = 190 365) 89 197 30 814 (34.5) 58 383 (65.5) 101 168 45 496 (45.0) 55 672 (55.0)
Cohabitation status <0.001 <0.001
Cohabiting family members of a PwD 1174 526 (44.8) 648 (55.2) 1302 736 (56.5) 566 (43.5)
Non-cohabiting family members of a PwD 4034 1497 (37.1) 2537 (62.9) 4596 2220 (48.3) 2376 (51.7)
Family members without a PwD 83 989 28 791 (34.3) 55 198 (65.7) 95 270 42 540 (44.7) 52 730 (55.3)
Age (y) <0.001 <0.001
19-29 9905 2907 (29.3) 6998 (70.7) 11 052 4099 (37.1) 6953 (62.9)
30-39 11 557 3839 (33.2) 7718 (66.8) 13 959 5613 (40.2) 8346 (59.8)
40-49 15 508 5174 (33.4) 10 334 (66.6) 18 178 6935 (38.2) 11 243 (61.8)
50-59 17 534 5807 (33.1) 11 727 (66.9) 21 549 9608 (44.6) 11 941 (55.4)
60-69 16 794 5835 (34.7) 10 959 (65.3) 18 552 9193 (49.6) 9359 (50.4)
≥70 17 899 7252 (40.5) 10 647 (59.5) 17 878 10 048 (56.2) 7830 (43.8)
Marital status <0.001 <0.001
Never married 14 844 4725 (31.8) 10 119 (68.2) 12 317 4441 (36.1) 7876 (63.9)
Divorced, widowed or separated 3398 1510 (44.4) 1888 (55.6) 12 493 6604 (52.9) 5889 (47.1)
Married 70 955 24 579 (34.6) 46 376 (65.4) 76 358 34 451 (45.1) 41 907 (54.9)
No. of family members 0.004 <0.001
2-4 81 036 28 113 (34.7) 52 923 (65.3) 90 503 41 001 (45.3) 49 502 (54.7)
≥5 8161 2701 (33.1) 5460 (66.9) 10 665 4495 (42.1) 6170 (57.9)
No. of cohabiting generations <0.001 <0.001
Over two generations 6572 2218 (33.7) 4354 (66.3) 9397 4280 (45.5) 5117 (54.5)
Two generations 46 790 15 839 (33.9) 30 951 (66.1) 54 582 23 369 (42.8) 31 213 (57.2)
One (couple) 35 835 12 757 (35.6) 23 078 (64.4) 37 189 17 847 (48.0) 19 342 (52.0)
Family income level <0.001 <0.001
Very low 12 060 4997 (41.4) 7063 (58.6) 13 648 7255 (53.2) 6393 (46.8)
Low 26 006 9599 (36.9) 16 407 (63.1) 29 420 14 506 (49.3) 14 914 (50.7)
High 24 447 7883 (32.2) 16 564 (67.8) 27 859 11 742 (42.1) 16 117 (57.9)
Very high 26 684 8335 (31.2) 18 349 (68.8) 30 241 11 993 (39.7) 18 248 (60.3)
Highest level of education <0.001 <0.001
Illiterate 3364 1513 (45.0) 1851 (55.0) 10 553 6023 (57.1) 4530 (42.9)
Elementary school 11 363 4553 (40.1) 6810 (59.9) 16 212 8664 (53.4) 7548 (46.6)
Middle school 9953 3797 (38.1) 6156 (61.9) 10 857 5323 (49.0) 5534 (51.0)
High school 33 281 11 018 (33.1) 22 263 (66.9) 33 035 13 925 (42.2) 19 110 (57.8)
College and above 31 236 9933 (31.8) 21 303 (68.2) 30 511 11 561 (37.9) 18 950 (62.1)
Employment status <0.001 <0.001
Unemployed 22 448 8741 (38.9) 13 707 (61.1) 46 324 22 689 (49.0) 23 635 (51.0)
Blue-collar worker 37 603 12 827 (34.1) 24 776 (65.9) 20 460 9389 (45.9) 11 071 (54.1)
Pink-collar worker 8948 2875 (32.1) 6073 (67.9) 15 467 6465 (41.8) 9002 (58.2)
White-collar worker 20 198 6371 (31.5) 13 827 (68.5) 18 917 6953 (36.8) 11 964 (63.2)
Alcohol consumption (times/wk) <0.001 <0.001
>1 32 293 11 624 (36.0) 20 669 (64.0) 10 966 5086 (46.4) 5880 (53.6)
0-1 37 771 12 303 (32.6) 25 468 (67.4) 51 879 22 327 (43.0) 29 552 (57.0)
Never 19 133 6887 (36.0) 12 246 (64.0) 38 323 18 083 (47.2) 20 240 (52.8)
Smoking status <0.001 <0.001
Current 30 289 10 836 (35.8) 19 453 (64.2) 2474 1477 (59.7) 997 (40.3)
Past 34 227 12 419 (36.3) 21 808 (63.7) 2050 1144 (55.8) 906 (44.2)
Never 24 681 7559 (30.6) 17 122 (69.4) 96 644 42 875 (44.4) 53 769 (55.6)
Physical activity <0.001 <0.001
Low 48 500 17 371 (35.8) 31 129 (64.2) 56 457 26 180 (46.4) 30 277 (53.6)
High 40 697 13 443 (33.0) 27 254 (67.0) 44 711 19 316 (43.2) 25 395 (56.8)
Depressive symptoms <0.001 <0.001
No 87 151 29 050 (33.3) 58 101 (66.7) 97 224 41 943 (43.1) 55 281 (56.9)
Yes 2046 1764 (86.2) 282 (13.8) 3944 3553 (90.1) 391 (9.9)
No. of chronic diseases1 <0.001 <0.001
≥1 28 526 10 931 (38.3) 17 595 (61.7) 28 143 14 954 (53.1) 13 189 (46.9)
0 60 671 19 883 (32.8) 40 788 (67.2) 73 025 30 542 (41.8) 42 483 (58.2)

Values are presented as number or number (%).

PSQI, Pittsburgh Sleep Quality Index; PwD, person with dementia.

1

A chronic disease was defined as a diagnosis of hypertension or diabetes mellitus; The number of chronic diseases is the sum of the number of the above diagnoses.

Table 2.

Demographic characteristics of participants according to cohabitation status

Variables Cohabitation status
Total Family members without a PwD Non-cohabiting family members of a PwD Cohabiting family members of a PwD p-value
Male (n = 89 197) 89 197 83 989 (94.2) 4034 (4.5) 1174 (1.3)
Age (y) <0.001
19-29 9905 9224 (11.0) 590 (14.6) 91 (7.8)
30-39 11 557 11 180 (13.3) 318 (7.9) 59 (5.0)
40-49 15 508 14 647 (17.4) 717 (17.8) 144 (12.3)
50-59 17 534 16 070 (19.1) 1187 (29.4) 277 (23.6)
60-69 16 794 15 731 (18.7) 840 (20.8) 223 (19.0)
≥70 17 899 17 137 (20.4) 382 (9.5) 380 (32.4)
Marital status <0.001
Never married 14 844 13 887 (16.5) 749 (18.6) 208 (17.7)
Divorced, widowed or separated 3398 3203 (3.8) 89 (2.2) 106 (9.0)
Married 70 955 66 899 (79.7) 3196 (79.2) 860 (73.3)
No. of family members <0.001
2-4 81 036 76 401 (91.0) 3678 (91.2) 957 (81.5)
≥5 8161 7588 (9.0) 356 (8.8) 217 (18.5)
No. of cohabiting generations <0.001
Over two generations 6572 6050 (7.2) 201 (5.0) 321 (27.3)
Two generations 46 790 43 864 (52.2) 2409 (59.7) 517 (44.0)
One (couple) 35 835 34 075 (40.6) 1424 (35.3) 336 (28.6)
Family income level <0.001
Very low 12 060 11 431 (13.6) 378 (9.4) 251 (21.4)
Low 26 006 24 646 (29.3) 959 (23.8) 401 (34.2)
High 24 447 23 084 (27.5) 1099 (27.2) 264 (22.5)
Very high 26 684 24 828 (29.6) 1598 (39.6) 258 (22.0)
Highest level of education <0.001
Illiterate 3364 3225 (3.8) 65 (1.6) 74 (6.3)
Elementary school 11 363 10 841 (12.9) 318 (7.9) 204 (17.4)
Middle school 9953 9426 (11.2) 367 (9.1) 160 (13.6)
High school 33 281 31 125 (37.1) 1714 (42.5) 442 (37.6)
College and above 31 236 29 372 (35.0) 1570 (38.9) 294 (25.0)
Employment status <0.001
Unemployed 22 448 21 113 (25.1) 870 (21.6) 465 (39.6)
Blue-collar worker 37 603 35 479 (42.2) 1653 (41.0) 471 (40.1)
Pink-collar worker 8948 8404 (10.0) 469 (11.6) 75 (6.4)
White-collar worker 20 198 18 993 (22.6) 1042 (25.8) 163 (13.9)
Alcohol consumption (times/wk) <0.001
>1 32 293 30 404 (36.2) 1498 (37.1) 391 (33.3)
0-1 37 771 35 487 (42.3) 1859 (46.1) 425 (36.2)
Never 19 133 18 098 (21.5) 677 (16.8) 358 (30.5)
Smoking status 0.134
Current 30 289 28 525 (34.0) 1386 (34.4) 378 (32.2)
Past 34 227 32 181 (38.3) 1554 (38.5) 492 (41.9)
Never 24 681 23 283 (27.7) 1094 (27.1) 304 (25.9)
Physical activity 0.003
Low 48 500 45 632 (54.3) 2172 (53.8) 696 (59.3)
High 40 697 38 357 (45.7) 1862 (46.2) 478 (40.7)
Depressive symptoms <0.001
No 87 151 82 096 (97.7) 3944 (97.8) 1111 (94.6)
Yes 2046 1893 (2.3) 90 (2.2) 63 (5.4)
No. of chronic diseases1 <0.001
≥1 28 526 26 877 (32.0) 1191 (29.5) 458 (39.0)
0 60 671 57 112 (68.0) 2843 (70.5) 716 (61.0) <0.001
Female (n = 101 168)
Age (y) 101 168 95 270 (94.2) 4596 (4.5) 1302 (1.3)
19-29 11 052 10 356 (10.9) 599 (13.0) 97 (7.5)
30-39 13 959 13 477 (14.1) 420 (9.1) 62 (4.8)
40-49 18 178 16 902 (17.7) 1094 (23.8) 182 (14.0)
50-59 21 549 19 846 (20.8) 1425 (31.0) 278 (21.4)
60-69 18 552 17 569 (18.4) 752 (16.4) 231 (17.7)
≥70 17 878 17 120 (18.0) 306 (6.7) 452 (34.7)
Marital status <0.001
Never married 12 317 11 497 (12.1) 670 (14.6) 150 (11.5)
Divorced, widowed, or separated 12 493 11 892 (12.5) 344 (7.5) 257 (19.7)
Married 76 358 71 881 (75.4) 3582 (77.9) 895 (68.7)
No. of family members <0.001
2-4 90 503 85 296 (89.5) 4162 (90.6) 1045 (80.3)
≥5 10 665 9974 (10.5) 434 (9.4) 257 (19.7)
No. of cohabiting generations <0.001
Over two generations 9397 8762 (9.2) 247 (5.4) 388 (29.8)
Two generations 54 582 51 201 (53.7) 2805 (61.0) 576 (44.2)
One (couple) 37 189 35 307 (37.1) 1544 (33.6) 338 (26.0)
Family income level <0.001
Very low 13 648 12 927 (13.6) 438 (9.5) 283 (21.7)
Low 29 420 27 888 (29.3) 1087 (23.7) 445 (34.2)
High 27 859 26 264 (27.6) 1295 (28.2) 300 (23.0)
Very high 30 241 28 191 (29.6) 1776 (38.6) 274 (21.0)
Highest level of education <0.001
Illiterate 10 553 10 102 (10.6) 186 (4.0) 265 (20.4)
Elementary school 16 212 15 473 (16.2) 453 (9.9) 286 (22.0)
Middle school 10 857 10 207 (10.7) 506 (11.0) 144 (11.1)
High school 33 035 30 799 (32.3) 1877 (40.8) 359 (27.6)
College and above 30 511 28 689 (30.1) 1574 (34.2) 248 (19.0)
Employment status <0.001
Unemployed 46 324 43 701 (45.9) 1912 (41.6) 711 (54.6)
Blue-collar worker 20 460 19 410 (20.4) 802 (17.4) 248 (19.0)
Pink-collar worker 15 467 14 402 (15.1) 854 (18.6) 211 (16.2)
White-collar worker 18 917 17 757 (18.6) 1028 (22.4) 132 (10.1)
Alcohol consumption (times/wk) <0.001
>1 10 966 10 295 (10.8) 556 (12.1) 115 (8.8)
0-1 51 879 48 703 (51.1) 2626 (57.1) 550 (42.2)
Never 38 323 36 272 (38.1) 1414 (30.8) 637 (48.9)
Smoking status 0.004
Current 2474 2334 (2.4) 120 (2.6) 20 (1.5)
Past 2050 1913 (2.0) 94 (2.0) 43 (3.3)
Never 96 644 91 023 (95.5) 4382 (95.3) 1239 (95.2)
Physical activity <0.001
Low 56 457 53 196 (55.8) 2461 (53.5) 800 (61.4)
High 44 711 42 074 (44.2) 2135 (46.5) 502 (38.6)
Depressive symptoms <0.001
No 97 224 91 639 (96.2) 4404 (95.8) 1181 (90.7)
Yes 3944 3631 (3.8) 192 (4.2) 121 (9.3)
No. of chronic diseases1 <0.001
≥1 28 143 26 665 (28.0) 963 (21.0) 515 (39.6)
0 73 025 68 605 (72.0) 3633 (79.0) 787 (60.4)

Values are presented as number or number (%).

PwD, person with dementia.

1

A chronic disease was defined as a diagnosis of hypertension or diabetes mellitus; The number of chronic diseases is the sum of the number of the above diagnoses.

Table 3.

Factors associated with poor sleep quality

Variables Poor sleep quality (PSQI>5)
Male Female
Cohabitation status
Cohabiting family members of a PwD 1.28 (1.08, 1.52) 1.40 (1.20, 1.64)
Non-cohabiting family members of a PwD 1.14 (1.05, 1.24) 1.23 (1.14, 1.33)
Family members without a PwD 1.00 (reference) 1.00 (reference)
Age (y)
19-29 0.86 (0.77, 0.96) 0.82 (0.74, 0.92)
30-39 1.04 (0.95, 1.14) 0.84 (0.78, 0.93)
40-49 0.97 (0.89, 1.06) 0.77 (0.72, 0.85)
50-59 0.92 (0.85, 0.99) 0.89 (0.83, 0.96)
60-69 0.90 (0.84, 0.96) 0.94 (0.88, 1.01)
≥70 1.00 (reference) 1.00 (reference)
Marital status
Never married 1.00 (0.93, 1.07) 0.79 (0.73, 0.85)
Divorced, widowed or separated 1.32 (1.20, 1.45) 1.03 (0.97, 1.09)
Married 1.00 (reference) 1.00 (reference)
No. of family members
2–4 1.00 (0.93, 1.08) 1.05 (0.98, 1.13)
≥5 1.00 (reference) 1.00 (reference)
No. of cohabiting generations
Over two generations 1.05 (0.96, 1.16) 1.04 (0.96, 1.13)
Two generations 1.12 (1.07, 1.17) 1.08 (1.03, 1.13)
One (couple) 1.00 (reference) 1.00 (reference)
Family income level
Very low 1.21 (1.13, 1.30) 1.20 (1.12, 1.29)
Low 1.15 (1.09, 1.22) 1.14 (1.08, 1.19)
High 1.01 (0.96, 1.06) 1.01 (0.97, 1.06)
Very high 1.00 (reference) 1.00 (reference)
Highest level of education
Illiterate 1.41 (1.25, 1.59) 1.44 (1.32, 1.58)
Elementary school 1.31 (1.21, 1.41) 1.45 (1.35, 1.57)
Middle school 1.27 (1.18, 1.36) 1.30 (1.22, 1.40)
High school 1.05 (1.00, 1.10) 1.09 (1.04, 1.14)
College and above 1.00 (reference) 1.00 (reference)
Employment status
Unemployed 1.08 (1.01,1.15) 1.12 (1.06, 1.17)
Blue-collar worker 1.01 (0.96, 1.07) 0.99 (0.93, 1.06)
Pink-collar worker 0.97 (0.91, 1.04) 0.98 (0.92, 1.04)
White-collar worker 1.00 (reference) 1.00 (reference)
Alcohol consumption (times/wk)
>1 1.18 (1.12, 1.25) 1.26 (1.18, 1.33)
0-1 1.05 (1.00, 1.11) 1.11 (1.07, 1.15)
Never 1.00 (reference) 1.00 (reference)
Smoking status
Current 1.21 (1.15, 1.27) 1.52 (1.36, 1.71)
Past 1.19 (1.13, 1.25) 1.52 (1.36, 1.71)
Never 1.00 (reference) 1.00 (reference)
Physical activity
Low 1.10 (1.06, 1.14) 1.11 (1.07, 1.14)
High 1.00 (reference) 1.00 (reference)
Depressive symptoms
No 0.09 (0.07, 0.10) 0.09 (0.08, 0.10)
Yes 1.00 (reference) 1.00 (reference)
No. of chronic disease1
≥1 1.18 (1.13, 1.23) 1.18 (1.12, 1.23)
0 1.00 (reference) 1.00 (reference)

Values are presented as adjusted odds ratio (95% confidence interval).

PSQI, Pittsburgh Sleep Quality Index; PwD, person with dementia.

1

A chronic disease was defined as a diagnosis of hypertension or diabetes mellitus; The number of chronic diseases is the sum of the number of the above diagnoses.