Dr. Song is a graduate, Dr. Dowling is Professor and Chair, Dr. Wallhagen is Professor, Department of Physiological Nursing, Dr. Lee is Professor and James P. and Marjorie A. Livingston Endowed Chair in Nursing, and Director, T32 Nurse Research Training in Symptom Management, Department of Family Health Care Nursing, Ms. Hubbard is Research Staff Member, School of Nursing, University of California, San Francisco, and Dr. Strawbridge is Adjunct Professor, Institute for Health and Aging, San Francisco, California. In addition, Dr. Dowling is Director, and Ms. Hubbard is Research Staff Member, Institute on Aging Research Center, and Dr. Dowling is Associate Director, and Dr. Wallhagen is Director, John A. Hartford Center of Geriatric Nursing Excellence, School of Nursing, University of California, San Francisco, San Francisco, California.
The authors disclose that they have no significant financial interests in any product or class of products discussed directly or indirectly in this activity. The authors gratefully acknowledge research support from the School of Nursing Century Club, University of California, San Francisco.
Address correspondence to Glenna A. Dowling, PhD, RN, FAAN, Professor and Chair, Department of Physiological Nursing, University of California, San Francisco, 2 Koret Way, Room N 631, San Francisco, CA 94143; e-mail: firstname.lastname@example.org.
Sleep problems become more common as people age and occur in more than half of adults age 65 and older (Kryger, Monjan, Bliwise, & Ancoli-Israel, 2004). Sleep is severely fragmented in institutionalized older adults, particularly those with dementia. Studies in several countries, including the United States, have confirmed that nursing home residents have poor sleep quality at night, spend an extended time in bed during the day, and nap frequently (Fetveit & Bjorvatn, 2002, 2006; Shochat, Martin, Marler, & Ancoli-Israel, 2000). In a study of sleep-wake activity using actigraphy in nursing home residents, researchers found that sleep was extremely fragmented in older adults with dementia (Ancoli-Israel, Klauber, et al., 1997). Moreover, the group with severe dementia had a lower activity mesor (mean) and a more blunted amplitude (height of the peak), and was more phase-delayed in their rhythm than patients with moderate, mild, or no dementia. Disruptions in circadian rhythm are associated with shorter life span (Gehrman et al., 2004), and severe nighttime sleep disturbances result in excessive daytime sleepiness in institutionalized older adults with dementia (Pat-Horenczyk, Klauber, Shochat, & Ancoli-Israel, 1998).
Many factors affect sleep. Some are part of the physical and social environment in which one lives, and others are part of one’s personal characteristics and medical conditions. For example, environmental level of light exposure must be accounted for because bright light is a powerful circadian synchronizer and directly influences circadian rhythms such as sleep-wake activity and secretion of melatonin (Czeisler & Gooley, 2007). Institutionalized individuals with dementia are rarely exposed to bright light of more than 2,000 lux (Ancoli-Israel, Klauber, et al., 1997; Shochat et al., 2000). Within the institutional environment, social factors, such as patterns of care, activities, and personal relationships between residents and staff, can also affect older people (Alessi & Schnelle, 2000). Finally, sleep can be dramatically affected by a person’s age (Ancoli-Israel & Cooke, 2005), gender (Redline et al., 2004), race (Carpenter, Strauss, & Patterson, 1995), medications (Alessi & Schnelle, 2000), comorbid conditions (Ayalon, Liu, & Ancoli-Israel, 2004; Vitiello & Borson, 2001), genetics (Craig, Hart, & Passmore, 2006), depression, and general mental health (Lopez et al., 2003).
Korea has one of the most rapidly growing populations of older adults in the world (Hayutin, 2007). Institutions for older adults are proliferating, becoming increasingly important providers of senior care in modern Korean society. For example, the number of assisted living and nursing home facilities increased from 278 in 2002 to 1,584 in 2007 (Ministry for Health Welfare and Family Affairs, 2008, 2009). However, most studies of sleep in institutionalized older adults with dementia have been conducted in Western countries, and their generalizability to Eastern countries is unknown.
Given the data on the vulnerability of older adults with dementia to poor sleep, nurses must assess sleep-related parameters to identify potential problems. Recognizing rest-activity patterns can determine the causes of sleep disturbance, while investigating other contributing factors will provide for effective interventions, appropriate care plans, and treatments to improve sleep quality.
The purpose of this study was to describe rest-activity patterns in older adults with dementia and to investigate the personal and behavioral characteristics and environmental factors associated with sleep in two Korean care settings: a nursing home and an assisted living facility. The research questions were:
- What are the nocturnal sleep and daytime sleep characteristics in a sample of older adults with dementia residing in either a nursing home or an assisted living facility in Korea?
- What are the rest-activity rhythm characteristics in this sample?
- Are there significant relationships between nocturnal sleep, daytime sleep, rest-activity rhythms, and other factors (e.g., age, comorbid conditions, type and duration of dementia, medication use, cognitive function, problematic behaviors, light levels, type of institution)?
Participants and Settings
To be included in this study, residents had to be Korean; age 65 or older; medically diagnosed with dementia as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (American Psychiatric Association, 1994); institutionalized for at least 3 months; and capable of independent ambulation. Residents were excluded from participating in this study if their score on the Mini-Mental State Examination-Korean version (MMSE-K) (Kwon & Park, 1989) was 24 or higher or if they had moderate-to-severe pyramidal or extrapyramidal motor symptoms, such as a severely abnormal gait, intention tremor, hemiparesis, or myoclonus. These conditions would have affected the validity of rest-activity measures that use motion detectors.
The study was conducted in two institutions in South Korea. Institution A is a for-profit assisted living facility that does not provide residents with structured activities except for meals, which are served at fixed times: breakfast at 8 a.m., lunch at noon, and dinner at 6 p.m. Each resident has a private room with a private bathroom. Institution B is a not-for-profit nursing home that provides residents with a structured daytime routine that includes fixed meal times: breakfast at 7:30 a.m., lunch at noon, and dinner at 6 p.m. The residents share rooms and bathrooms (three to four residents per room). A total of 12 female residents participated in this study: 4 from Institution A, whose resident population is mostly women, and 8 from Institution B, whose resident population is entirely women.
The Actiwatch® activity monitor (AW-64, Mini Mitter Co., Inc., Bend, Oregon) was used to collect rest-activity data. The Actiwatch, which looks like a small wristwatch, is a compact, battery-operated, activity monitor that stores activity counts in a memory chip (Dowling, Mastick, Hubbard, Luxenberg, & Burr, 2005). Actigraphy is based on the principle that people move less during sleep and more when they are awake (Littner et al., 2003). It is useful when polysomnography is impractical, such as for patients with dementia. Wrist activity has been used extensively in studies involving older adults with dementia, particularly in nursing homes (Ancoli-Israel et al., 2003; Dowling et al., 2007; Dowling, Hubbard, et al., 2005; Gehrman et al., 2003). Criterion validity is well established, with correlations between actigraphy and polysomnography reported for total sleep time (r = 0.81 to 0.91) and for percentage sleep (r = 0.61 to 0.78) in patients with dementia in a nursing home (Ancoli-Israel, Clopton, Klauber, Fell, & Mason, 1997). The AW-64 model activity monitor has also revealed moderate to high correlations to polysomnography when measuring sleep characteristics (i.e., number of awakenings, wake time after sleep onset, total sleep time, sleep efficiency) for people with insomnia, including older adults (Lichstein et al., 2006).
Daytime (8 a.m. to 6 p.m.) and nighttime (6 p.m. to 8 a.m.) were defined by each institution’s usual routine for bedtime and risetime. Information on actual time in bed and risetime was impossible to attain for each participant because of staff workload and participants’ inability to self-report. This method of defining daytime and nighttime has been used in other studies of sleep in individuals with dementia (Ancoli-Israel, Martin, Kripke, Marler, & Klauber, 2002; Dowling, Mastick, et al., 2005).
Actigraphic data were used to calculate nighttime variables (i.e., total sleep time, wake time, mean duration of wake episodes during the night, number of wake episodes). Daytime variables, such as sleep time and the number of sleep events, were also calculated between 8 a.m. and 6 p.m. Rest-activity pattern parameters were calculated from actigraphic data and included (Dowling et al., 2007; Van Someren et al., 1999):
- Interdaily stability (i.e., consistency between days, indicating the strength of the rhythm) (range = 0 to 1, with higher values indicating a more stable rhythm).
- Intradaily variability (i.e., frequency and extent of transitions between rest and activity) (range = 0 to 2, with higher values indicating a more fragmented rhythm).
- L5 (i.e., the sequence of the 5 least active hours in a 24-hour period, with an average activity profile indicating the trough or nadir of the rhythm).
- M10 (i.e., the sequence of the 10 most active hours, indicating peak of the rhythm).
- Amplitude (i.e., the difference between M10 and L5 in an average 24-hour period).
- Relative amplitude (i.e., the normalized difference between M10 and L5 in an average 24-hour pattern) (range = 0 to 1, with higher values indicating a stronger rhythm).
Medical records were reviewed to assess each participant’s demographic characteristics, and health state. The MMSE-K, the version translated by Kwon and Park (1989), was used to estimate cognitive status based on the oripginal version (Folstein, Folstein, & McHugh, 1975). It consists of 12 questions that test six areas of cognitive function: orientation, registration, attention, recall, language, and understanding and judgment. Scores range from 0 to 30; scores below 24 indicate cognitive impairment. The Cronbach’s alpha coefficient was 0.82 in a study of Korean individuals with dementia (H.K. Kim & Lee, 2000). The Problematic Behavior Scale, developed by K.A. Kim (2003), was used to assess the frequency of behavior problems. It consists of 25 items that assess aggressive psychomotor behaviors, nonaggressive psychomotor behaviors, and irritated behaviors. The total score ranges from 0 to 75, with higher scores indicating more problematic behaviors. High reliability (Spearman’s rho = 0.84) and validity (correlation coefficient r = 0.83) with the Korean version of the Neuropsychiatric Inventory have been reported (J.S. Kim & Jung, 2005; K.A. Kim, 2003). The light level in each setting was measured at the resident’s eye level using a calibrated precision light meter (cal-LIGHT 400™, Cooke Corporation, Romu-lus, Michigan).
The study was approved by the institutional review boards of the participating university and the two Korean institutions. The study settings were conveniently selected. The nursing director at each setting first determined prospective participants (N = 12) who met the eligibility criteria and whose authorized surrogates were considered to be potentially interested in having their relatives involved in the study. The directors explained the study when the surrogates visited their relatives. The surrogates were informed of possible benefits and side effects or risks and the right of each participant to withdraw from the study at any time. The surrogates were then given time to think about their relatives’ participation in the study. After receiving the notice from the director regarding the surrogates’ consent, the researcher directly contacted the surrogates and set up a face-to-face appointment to review the consent form. Written informed consent was obtained from 12 surrogates on the same or following visit. Assent was obtained from the participant.
Data were collected in April and May 2007. Each participant wore an Actiwatch on the dominant wrist for seven consecutive 24-hour periods; a nylon locking cable was affixed through the watch band to deter the participant from removing the monitor (Dowling, Mastick, et al., 2005). Medical records were reviewed on the first day of data collection to assess each participant’s demographics and health state. These factors included age, comorbid conditions, gender, type and duration of dementia, medication use, and length of stay at the institution. The MMSE-K data were obtained by resident interviews on the first day of the study. The Problematic Behavior Scale, a simple-to-use questionnaire that includes easy-to-follow guidelines (e.g., Shouts in a loud voice: never/rarely [1 time per week], occasionally [2 to 3 times per week], or always [twice daily]), was completed by nurses or assistants on the last day of data collection. Light level measures were taken in the morning (at 9:30 a.m.) and afternoon (at 3:30 p.m.) every day from baseline through the end of the study.
Data were analyzed using SPSS version 15.0. Descriptive statistics were calculated for all variables. Mann-Whitney U tests were performed to compare group (i.e., two settings) differences on sleep-wake and rest-activity rhythm variables. Spearman’s rho was used to test the relationships between sleep-wake variables and rest-activity rhythm parameters, as well as other personal and environmental factors (e.g., age, cognitive function, problematic behaviors, light exposure). Statistical analysis was performed using p = 0.05 significance level.
Adherence to Actigraphy
Two participants were withdrawn from the study. The first removed the activity monitor before any recordable data had been collected. The second developed a mild skin rash on the third day, but the partial data obtained from the first 2 days were sufficient to include in the sleep and wake variable analyses (N = 11) but not the rest-activity rhythm analyses (N = 10). Participants had an average of 137 hours of valid data (SD = 30, age range = 96 to 168).
The mean age of the 11 participants included in the data analysis was 85.6 (SD = 7.2 years, age range = 70 to 95). Four participants were diagnosed with Alzheimer’s disease, 1 had vascular dementia, and 6 had no specific type of dementia diagnosis. The duration of institutionalization varied from 5 months to 10 years. Most of the participants had comorbid conditions, including high blood pressure, diabetes, and arthritis. Six participants were taking medications for their comorbid conditions, and 3 were taking supplements that included vitamins and calcium. The average MMSE-K score was 13.1 (SD = 4.0, range = 5 to 21). The scores for the Problematic Behaviors Scale were low, averaging 6.9 (SD = 6.3, range = 1 to 21). The average light level during the afternoon was moderate at 2,038 lux (SD = 288) in the common areas (2,378 lux, SD = 41, at Institution A and 1,832 lux, SD = 51, at Institution B) and low at 591 lux (SD = 498) in the bedrooms (1,048 lux, SD = 601, at Institution A and 330 lux, SD = 121, at Institution B).
Sleep Time and Wake Time
At night, the average total sleep time was 7.6 hours (SD = 0.7), and the ratio of total sleep time to time in bed was 0.76 (SD = 0.07), indicating low sleep continuity. The average total wake time was 72.2 minutes (SD = 28.9), ranging widely from 12.0 to 106.4 minutes. The average duration of wake episodes was 3.4 minutes (SD = 1.4), and the number of wake episodes averaged 22 (SD = 9). During the daytime, napping behavior was considerable, with a mean of 4.3 hours (SD = 2.4) of sleep during the day between 8 a.m. and 6 p.m.
The oldest person, age 95, had the longest sleep (9.1 hours), the least wake time (12 minutes) during the night, and the longest sleep (9.7 hours) during the day. No significant differences in sleep parameters between the environmental setting, cognitive function, or other variables were detected.
Mean interdaily stability was moderate at 0.47 (SD = 0.14), and mean intradaily variability was slightly high at 1.36 (SD = 0.27). Mean onset of 5 least active hours in the 24-hour average activity profile occurred at 10:09 p.m., indicating phase delay. A significant difference in rest-activity rhythms was found between the two institutions (Table). Residents at Institution A had lower interdaily stability (0.35, SD = 0.12) than the residents at Institution B (0.56, SD = 0.08). Mean activity during L5 was significantly higher in residents at Institution A (25.09, SD = 11.99; median = 19.38) compared with those at Institution B (13.63, SD = 5.01; median = 15.38). Relative amplitude was significantly lower in Institution A (0.77, SD = 0.07), indicating stronger rhythms in residents in Institution B (0.89, SD = 0.07). The Figure illustrates median rest-activity patterns for residents in both institutions.
Table: Means and Medians of Restfiactivity Rhythm by Type of Institution (N = 10)
Figure. Median Rest-Activity Rhythm by Type of Institution (institution A, n = 4; Institution B, n = 6).
This pilot study supports the hypothesis that institutionalized older Korean adults with dementia have sleep disturbances that include multiple awakenings at night and significant napping during the day. These findings are consistent with studies of other ethnic and racial groups (Bonanni et al., 2005; Fetveit & Bjorvatn, 2006) and suggest that the sleep characteristics of institutionalized Korean adults with dementia do not differ from non-Korean residents with similar characteristics in the United States or other Western countries.
Participants’ rest-activity rhythm was fragmented and phase-delayed. These characteristics of disrupted rhythms are also consistent with other studies of older adults with dementia (Fetveit & Bjorvatn, 2006; Harper et al., 2005; Motohashi, Maeda, Wakamatsu, Higuchi, & Yuasa, 2000).
Our study also examined the relationships between rest-activity characteristics and other variables, including demographic data, health state, cognitive function, problematic behaviors, light levels, and type of institution. Significant relationships were only found by type of institution. The residents at Institution B, the not-for-profit nursing home, had stronger and more stable rest-activity rhythms than those at Institution A, the for-profit assisted living facility. These findings imply that rest-activity rhythms may be influenced by the environmental setting. Scheduled activity programs and fixed mealtimes were provided at Institution B, whereas residents at Institution A did not have any structured routines except for mealtimes and were encouraged to spend their time privately. Although this study did not investigate institutional environment factors in depth, the significant difference in rest-activity rhythms by type of institution may be related to the staff-resident ratio, the kinds of activities offered, or the imposition of structure around activities of daily living.
This is the first study to use actigraphy to objectively measure sleep in Korean older adults with dementia. A few studies have measured sleep in older adults with dementia in Korea using subjective measurements. For example, using self-reported sleep questionnaires, M. Kim, Cho, Lee, Jeong, and Park (1998) found that older adults reported their nocturnal sleep time to be significantly less, and sleep onset tended to be phase-delayed after they were admitted to the hospital than before admission. Although other studies (K. Kim, 2000a, 2000b) have investigated sleep characteristics and influencing factors in nursing homes and the community, these studies did not compare sleep in different settings.
Many studies have examined patients in nursing homes, but only a few sleep studies have compared different types of institutions. Kuhn, Edelman, and Fulton (2005) investigated daytime sleep among 166 adults with dementia in three different settings: three nursing homes, two assisted living facilities, and three adult day centers. Sleep characteristics were assessed by sleep observations made between 9 a.m. to 3 p.m. on a weekday. Daytime sleep was observed more frequently in residential care settings than in adult day care centers. Moreover, residents who participated in staff-led activities (e.g., exercises, games, dancing) had less daytime sleep than those who did not participate in the activities (Kuhn et al., 2005).
The clinical significance of how rest-activity rhythm differs by type of institution has not been systematically studied. However, environmental setting may affect residents’ quality of life, daily functioning, or other health outcomes related to rest-activity rhythms. This pilot study elucidates the association between the institutional environment and the rest-activity rhythm in residents of different kinds of facilities. A facility that provides structured programs could benefit its residents’ health and circadian rhythms. Femia, Zarit, Stephens, and Greene (2007) reported that programs offered at adult day care centers can decrease the nighttime sleep problems experienced by patients with dementia. More studies are needed to determine whether differences in rest-activity rhythms between care settings are due to lifestyle, staffing pattern, or other factors. Investigating the effects of sleep and circadian rhythms on other health outcomes (e.g., depression) by type of environmental setting is also necessary.
This study has several limitations. First, all participants were women. The generalizability of the findings is limited by the small sample and lack of a comparison group of healthy older adults living independently. Further research with a larger sample should be conducted at various facilities, such as nursing homes, assisted living facilities, and hospitals, and include a control group of older adults living in community settings. In addition, because these facilities do not require detailed patient medical records, data on dementia-specific diagnoses were not available. More frequent light level measurements over the 24-hour period would have been useful to determine relationships between light exposure and sleep. Other important variables, such as depression and sleep accommodations (e.g., bed, futon), should also be investigated.
This study defined daytime and nighttime as the risetime and bedtime enforced by the institutions. This was done because staff were not always present to note the actual time for each study participant, and institutions usually schedule bedtime at a fixed hour. However, using a fixed risetime and bedtime may have underestimated sleep efficiency (i.e., amount of total sleep time divided by time in bed) because of a prolonged time in bed (Dowling, Mastick, et al., 2005).
Implications for Nursing
The importance of sleep and related rhythms in maintaining and improving health in older adults is often underestimated, particularly in people with dementia and those who reside in institutions. Despite this study’s limitations, the results suggest ways to enhance the care of older adults with dementia who have sleep-wake rhythm problems. First, improving nighttime sleep, time awake during the day, and rest-activity rhythm should be part of nursing care plans. Second, nurses in various kinds of institutions should be knowledgeable about and able to assess sleep-wake rhythms in older adults with dementia. In an ideal world, using sleep diaries or actigraphy for at least 1 week could help nurses evaluate residents’ sleep patterns, including wake time and sleep onset and its rhythmicity.
This study also suggests that geriatric nurses who care for older adults with dementia in institutional settings should consider how environmental factors influence residents’ sleep and circadian rhythms. These factors may include activity, social interaction, daytime routines, or lifestyle. Because this study’s findings are based on a small sample, geriatric nurse researchers could replicate studies that examine sleep and rest-activity rhythms in various settings. Collaborative research could recruit larger samples and increase the applicability of findings to nursing practice and health care.
This study’s results suggest possible effects of environmental factors on rest-activity rhythm in institutionalized older adults with dementia. In institutions that provided structured routines, residents had more stable and stronger rest-activity rhythms than those at institutions with less structure. More research with larger samples is needed to determine which factors contribute to sleep and rhythm problems in older adults with dementia, particularly in institutional settings, such as nursing homes and assisted living facilities. The findings of subsequent research in this area will facilitate interventions for sleep problems in institutionalized older adults with dementia.
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Means and Medians of Restfiactivity Rhythm by Type of Institution (N = 10)
|Mean (SD), Median|
|Variable||Total||Institution A (For profit)||Institution B (Not for profit)|
|Interdaily stability||0.47 (0.14) 0.49||0.35 (0.12*) 0.37||0.56 (0.08*) 0.53|
|Intradaily variability||1.36 (0.27) 1.34||1.22 (0.12) 1.24||1.46 (0.30) 1.46|
|Activity during 5 least-active (L5) hours||18.21 (9.84) 17.09||25.09 (11.99*) 19.38||13.63 (5.01*) 15.38|
|Onset of L5 (hh:mm:ss)||22:09:12 (1:45:56) 21:58:00||22:23:15 (1:41:39) 22:30:30||21:59:50 (1:57:12) 21:29:30|
|Activity during 10 most-active (M10) hours||261.67 (147.40) 218.19||200.04 (62.58) 214.70||302.76 (178.04) 221.45|
|Onset of M10 (hh:mm:ss)||9:29:30 (1:13:41) 9:51:00||8:53:00 (1:51:23) 9:46:30||9:53:50 (0:23:30) 10:02:00|
|Amplitude||243.45 (147.99) 201.09||174.95 (56.05)195.30||289.12 (176.86) 211.48|
|Relative amplitude||0.84 (0.09) 0.85||0.77 (0.07*) 0.77||0.89 (0.07*) 0.90|