.
0895-4356/91 $3.00+ 0.00 Copyright 0 1991Pcrgamon Pressplc
J m Epldem&l Vol.44,No. 1,pp.5-13,1991 Printedin Great Britain. All rights reserved
SLEEP PATTERNS IN RURAL ELDERS: HEALTH, AND PSYCHOBEHAVIORAL
DEMOGRAPHIC, CORRELATES
EYA~SUHABTE-GABR,’ROBERTB. WALLACE:PATRICIAL. COLSHER,~ JAMESR. HULBERT,~LON R. WHITERand IAN M. Se ‘HurleyMedicalCenter, MichiganState University,Flint, Michigan,‘Departmentof Preventive Medicineand EnvironmentalHealth, The Universityof Iowa, Iowa City, IA 52242,3National Instituteon Aging,Bethesda,Marylandand ‘Departmentof InternalMedicine,The Universityof Iowa, Iowa City, IA 52242,U.S.A. (Received
in revised form
20 July 1990)
Abstract-Altered sleep patterns, including changes in bedtime, sleep latency, total sleep time, and arising time, have been reported to occur with increasing age. We examine self-reported sleep patterns in a geographically-defined population (n = 3097)of persons aged 65 years and older. Sleep patterns were characterized according to demographic variables, clinical conditions, and physical, psychological, and social functioning. Sleep latency and total hours of sleep increased with age, and older respondents went to bed earlier. The percentage of respondents who reported feeling rested in the morning decreased with age. Women went to bed later, had longer sleep latency, and fewer hours of sleep than men, and were less likely to report feeling rested than men. Sleep patterns were also related to educational attainment, self-perceived health status, physical functional status, psychotropic drug use, alcohol use, depressive symptoms, life satisfaction, and social and recreational activity level. This population study suggests that sleep problems among the elderly are sometimes associated with treatable health conditions and modifiable behavioral and environmental characteristics. Geriatrics
Sleep patterns
Epidemiology
INTRODUCTION
of aging
There is some disagreement as to the extent to which age-related changes in sleep patterns represent normal as opposed to pathological changes [I, 51. A number of chronic conditions common among older persons are associated with change8 in sleep patterns, including myocardial infarction [ 191, congestive heart failure [20], stroke and multi-infarct dementia [21,22], chronic obstructive pulmonary disease [23], arthritis [24], urinary incontinence [25], Alzheimer’s disease [21,26] and depression [27-301. Sleep apnea and “restless-leg” syndrome [3 l-341 are associated with increasing age and sleep complaints. The use of various drugs, including psychotropic [34] and cardiovascular agents [34,35], is related to sleep disruptions. The elderly may be particularly vulnerable to
A number of age-associated changes in sleep patterns have been reported in both the clinical and experimental literature [ 1,2], including changes in bedtime [33, sleep latency [2,4-121, latency and amount of rapid eye movement (REM) sleep [2, 13, 141, time of awakening [2-4,7,11, 151, number of awakenings during the night [2,3,6-10, 16,171, total sleep time [2,3,9, 131, and sleep efficiency, or the ratio of the total sleep time to the total time in bed [2, 131. Older persons are also more likely than younger persons to have sleep-related complaints [l, 2,4,5,&g, 18]. From 10 to 50% of elderly persons report some type of sleep problem [4,5,8,9,18]. 5
EYASSUHABTE-GABR et al.
6
anesthesia- [36] and alcohol- [l] associated sleep disruption. Sleep disorders among the elderly are also associated with increased mortality risk L371. Because age-associated sleep disturbances are associated with morbidity and mortality, it is of importance to characterize their prevalence and understand the relation of sleep patterns to a variety of age-related health and psychobehavioral alterations. In this paper, we describe the sleep patterns in a geographically-defined cohort of community-dwelling elders, with these patterns characterized according to physical, psychological, and social health and function.
Further demographic characteristics of the respondents are given in Table 1. Less than half of the men had high school educations or greater, but more than half of the women did. Most men lived with someone else, although only about half of the women did. Most men were married, but most women were widowed. Most respondents were not employed. Questionnaire
Four sleep-related questions were used in the present study: (1) What time do you usually go to bed? (2) What time do you usually fall asleep? (3) What time do you usually get out of bed in the morning? (4) How often do you feel really rested when you wake up in the morning? Most of the time, some of the time, or rarely or never?
METHODS
Respondents
Respondents were participants in the Iowa 65 + Rural Health Study (RHS), a longitudinal population-based health survey of persons 65 years of age and older in two Iowa counties [38]. The RHS baseline survey which comprises this report was begun in 1982, and included 3673 persons, or approx. 80% of the target population. 3097 persons (84% of the cohort) completed the full in-person questionnaire on which these analyses were based, including 1155 men (mean age = 73.7 years) and 1942 women (mean age = 74.8 years). The remaining interviews were abbreviated or proxy interviews and will not be further considered.
Sleep latency was computed as the difference between time of falling asleep and bedtime, and respondents were classified as having latencies of more than 30 minutes, or 30 minutes or less. Respondents were classified as feeling rested most of the time or less than most of the time. Total sleep time was the difference between time of getting out of bed and time of falling asleep. Because of inconsistent data (e.g. falling asleep or waking up at a time prior to the reported bedtime), extreme times (e.g. reporting usually
Table 1. Demographic characteristics of respondents Men (%)
Women (%)
Total (%)
362 (31) 328 (28) 252 (22) 128(11) 85 (7)
510 (26) 508 (26) 443 (23) 299 (15) 182 (9)
872 (28) 836 (27) 695 (22) 427 (14) 267 (9)
685 (59) 283 (25) 182 (16)
883 (45) 616 (32) 430 (22)
1568 (51) 899 (29) 612 (20)
975 (84) 180(16)
986 (5 1) 956 (49)
1961 (63) 1136(37)
945 (82) 148 (13) 62 (5)
803 (41) 958 (49) 181 (9)
1748 (56) 1106 (36) 243 (8)
253 (22) 897 (78)
251 (13) 1683(87)
:2580 (84)
Age group (in yr)
6569 70-74 75-79 80-84 r84 Educational atlainment
Less than high school High school More than high school Residential status
With someone else Alone Marital status
Married Widowed Other* Work-retirement status?
Working Not working
504(16)
*Other marital status includes never married, divorced and separated. tworking includes working full time or part-time; not working includes retired, unemployed, and housewife.
1
Sleep Patterns in Rural Elders
having less than 2 or more than 14 hours of sleep), and missing data (e.g. “don’t know” responses), 139 persons were excluded from the analyses of usual bedtime, sleep latency, and total sleep time. The physical health and function variables included lifetime history of physician-diagnosed stroke, myocardial infarction, and emphysema, self-reported history during the past year of joint pain and morning stiffness, body mass index (weight divided by the square of height), use of psychotropic drugs (narcotics, sedatives, antipsychotics, and antianxiety agents) during the 2 weeks prior to interview, use of alcohol in the past month, and hospitalization during the past year. Gross physical function status was measured as limitations in self-reported ability to walk a half mile, walk up and down a fiight of stairs and do heavy housework [39]. Depressive symptoms were measured with a modified version of the Center for Epidemiologic Studies Depression Scale [40]. A life satisfaction scale [41] was also included. A test of free-recall memory, which consisted of 20 common one to two syllable nouns read to respondents, who then recalled as many as they could [38] was administered. Social activities/networks 11
measures included self-reported group membership, presence of a confidante, and attendance at religious services. Exercise levels were derived from a list of leisure activities [42]. Data analysis Mean bedtime, mean total sleep time, percentage of respondents with sleep latency over 30 minutes, and percentage of respondents feeling rested in the morning were obtained according to categories of demographic characteristics and physical, psychological, and social health and function. Analysis of variance was used to assess the statistical significance of differences in continuous variables between men and women, and among age groups for both genders. Chisquare analyses was used to assess the differences in categorical variables between men and women, and among age groups for both genders. Analyses of the health and functional characteristics were gender-specific and used age-adjusted values. Analysis of covariance (with age as covariate) was used to assess statistical significance for continuous variables, and logistic regression models were constructed for categorical variables, with age entered prior to the predictor of interest.
1
9.0-
6.63 2
6.6-
c, 8 'D c.n
6.4-
1
6.2.
2 6.0-
9’
7.61
I
65.69
70-74 ABe
75.79
60-64
65.69
65+
70-74
75-79
60-64
65+
Age Group (years)
Group (year@
m
90.0
.g 4
67.5
65.0-
LT
62.5-
= ;
60.0-
s.
es-es
70-74 Age
75-79
60-64
Group (years)
" a 3
77.5-
$
75.0'
I 65.69
70-74
75-79
WGrw(waW
Fig. 1. Gender- and age group-specific sleep patterns.
60-64
6S+
8
EYASSUHABTE-GABR et al. RESULTS
Figure 1 shows the age-specific mean bedtime, percentage of persons with sleep latency greater than 30 minutes, total hours of sleep, and percentage of persons feeling rested in the morning according to gender and age group. Women went to bed later than did men (unadjusted means = 10: 10 p.m. and 10:04p.m., respectively, p < O.Ol), slept fewer hours (unadjusted means = 8.1 and 8.2 hours, respectively, p < 0.05), were more likely to report sleep latencies exceeding 30 minutes (unadjusted percentages = 23.1 and 11.4, respectively, p < O.OOl), and were less likely to report feeling rested in the morning (unadjusted percentages = 78.6 and 82.9, respectively, p < 0.01). In gender-specific analyses, older men went to bed earlier (p < O.OOl), were more likely to have a sleep latency exceeding 30 minutes (p < 0.05), and reported more total hours of sleep (p < 0.001) than younger men. Older women went to bed earlier (p < 0.001) and slept longer (p < 0.05) than did younger women. No other differences were statistically significant. Table 2 shows sleep patterns according to demographic and employment characteristics. All values are age-adjusted. Men and women with more than a high school education went to bed later than less educated persons (p’s < 0.001) and women with more than a high school education got fewer hours of sleep than did less educated women (p < 0.05; not significant in men). Both men and women who lived alone went to bed later than did those who lived with others (p’s < 0.05 and 0.001, respectively) and women who lived alone reported fewer hours of sleep (p < 0.01). Women who worked got fewer hours of sleep (p < 0.001) and were more likely to report feeling rested in the morn-
ing (p < 0.05) than those who were not working. No other differences were statistically significant. Age-adjusted sleep patterns according to measures of physical health and function are shown in Table 3. Higher body mass index was associated with earlier mean bedtimes (p < 0.01) and more hours of sleep among women (p < 0.05), but was not significantly associated with any of the sleep parameters among men. History of heart attack (p < 0.001) and stroke (p < 0.05) were associated with decreased likelihood of feeling rested in the morning among women, and history of stroke was associated with increased likelihood of long sleep latency among men (p < 0.01). Emphysema, joint pain, and morning stiffness were all associated with decreased likelihood of feeling rested in the morning among both men and women (p’s < 0.001). Women who had been hospitalized in the year prior to interview reported earlier bedtimes (p < 0.05) and more hours of sleep (p < 0.05), were more likely to have long sleep latencies (p < 0.05) and less likely to feel rested in the morning (p < 0.001) than women who had not been hospitalized. The presence of physical functional limitations was associated with earlier bedtimes (significant in women only, p < O.Ol), increased sleep duration (p’s < O.Ol), increased likelihood of long sleep latency (p’s < O.OOl), and decreased likelihood of feeling rested in the morning (p’s -K 0.001). Men with relatively poor selfperceived health status reported earlier bedtimes (p < 0.05) and more hours of sleep (p < 0.05), but were less likely to report feeling rested in the morning (p < 0.001). Women with relatively poor self-perceived health status reported earlier bedtimes (p < O.OOl),were more likely to report long sleep latencies (p < 0.001) and less likely to
Table 2. Sleep patterns according to demographic characteristics Mean bedtime (p.m.)
% Sleep latency 130 min
Total night sleep (hr)
Men
Women
8.2* 8.0 8.0
81.8 84.3 85.5
71.6 19.4 79.3
8.1 8.2
8.0** 8.2
81.4 83.2
78.1 78.4
8.0 8.3
7 8*** 8:l
84.8 82.4
84.5* 77.7
Men
Women
Men
10:01*** 10: 16 IO:26
13.0 8.4 10.3
23.3 22.1 22.4
8.3 8.2 8.0
10: 13* to:02
10: 19*** IO:03
12.1 11.3
24.5 21.7
10:05 IO:03
10: 14 10: 11
7.9 12.3
20.7 23.4
Men Education High school
09: 55*** 10: 10 IO:25
Residential slam Alone With others Work stam Working Not working
*p < 0.05; **p < 0.01; ***p < 0.001.
Women
Women
% Feel rested
Sleep Patterns in Rural Elders Table 3. Sleep patterna
acco&ingto physical health and function % sleep later&y >3omm
Mean bedtime (p.m.) Men Body mass index Lower l/4 Upper l/4 Heart attack Yes No
9
Women
Total night sleep (hr)
Men
Women
Men
Women
% Feel rested Men
Women
10:02 1O:Ol
10: 15** 10:03
8.8 14.1
21.9 23.3
8.3 8.2
8.0* 8.2
82.2 78.5
18.3 79.4
10:09 10:02
10:07 10: 12
14.1 10.7
28.6 22.6
8.2 8.2
8.1 8.1
81.9 83.1
66.6*** 79.7
Stroke Yes No
09:56 10:04
1O:ll IO:11
21.8+* 10.6
24.5 23.0
8.4 8.2
8.2 8.1
77.1 83.3
68.4* 79.1
Emphysema Yes No
10:08 10:02
10:07 1O:ll
13.6 11.1
30.8 22.8
8.2 8.2
71.9*** 85.2
54.7*** 79.9
Joint pain Yes No
IO:04 10:04
10: 13 lo:08
12.2 10.0
23.7 21.6
8.2 8.2
8.1 8.1
79.5*** 89.5
74.9*** 85.9
10:04 10:02
10: 13 lo:08
12.3 10.5
23.7 22.4
8.2 8.2
8.1 8.1
77.6+** 88.1
73.3*** 84.7
(in past year) Yes No
1O:Ol 10:04
10:05* 10: 12
13.1 10.9
27.3, 22.1
8.3 8.2
8.1* 8.0
82.4 83.0
71.4*** 80.2
Physical function (Ho. limitations) Three Two One None
09:55 10:02 09:59 10:07
09:55** 10: 13 10: 16 1O:ll
19.8*** 20.2 13.7 9.0
33.8*** 27.5 24.6 20.2
8.7** 8.4 8.4 8.1
8.4** 8.2 8.1 8.0
67.9*** 72.3 79.1 87.2
57.0*** 63.3 78.3 84.9
Self-perceived health Poor Fair Good Excellent ’
09 : 59* 09:55 10:04 10: 13
09: 53*** 10:05 10: 10 10:22
18.5 12.5 11.3 8.8
40.7*** 30.0 21.2 16.6
8.5* 8.4 8.2 8.1
8.3 8.1 8.1 8.0
62.0*** 73.8 85.7 91.9
44.3*** 68.1 81.4 90.8
Morning stiffness Yes No
Hospitalization
*p < 0.05; **p < 0.01; ***p < 0.001.
report feeling rested in the morning (p < 0.001). No other differences were statistically significant. Table 4 shows the relationship between ageadjusted sleep patterns and substance use. Psychotropic drug use was associated with increased likelihood of long sleep latency among women (p < 0.001). Persons who used psychotropics were also less likely to report
that they felt rested in the morning (p’s c 0.001). Alcohol use was associated with later bedtimes among men (p < 0.05) and women (p < 0.001). The relationships between age-adjusted sleep patterns and psychological and social health and function are shown in Table 5. Persons with lower levels of depressive symptoms were less
Table 4. Sleep patterns according to substance use Mean bedtime (p.m.)
% Sleep latency > 30 min
Men
Women
Men
Psychotropic use Yes No
lo:oo IO:04
10:07 1O:ll
15.6 11.1
Alcohol use Yes No
10:08+ 09:59
10:22**; lo:08
11.8 11.0
Total night sleep (br)
% Feel rested
Men
Women
34.4*** 21.6
8.4 8.2
8.2 8.1
69.2*+* 83.6
64.4*** 80.1
22.7 23.2
8.2 8.3
8.0 8.1
84.5 81.5
81.5 77.7
Women
Psychotropic use refers to use in the 2 weeks prior to interview. Alcohol use refers to use in the month prior to interview. *p < 0.05; **p < 0.01; ***p < 0.001.
Men
Women
10
EYASSUHABTE-GABR et al. Table 5. Sleep patterns according to psychological and social health and function Mean bedtime (p.m.)
% Sleep latency > 30 min
Total night sleep fir) Men Women
% Feel rested
Men
Women
1O:ll’ lo:oo
IO: 14 lo:08
5.5*** 19.5
15.3*** 35.3
8.1 8.2
8.1 8.1
93.1*** 68.4
90.9*** 63.6
09: 58*** 10: 16
10:03*** lo:23
10.3 12.5
24.4 23. I
8.3* 8.1
8.2*** 7.9
81.0 84.0
80.0 79.0
09:54
10:07 1O:Ol 10:04 10:04 10: 12
10:07 10: 17 10: 14 IO:09 10: 16 10: 10
IO.92 14.7 9.1 8.0 11.7 8.2
28.2*** 21.3 25.1 19.3 18.3 18.4
8.4 8.1 8.3 8.2 8.2 8.3
8.1 8.0 8.1 8.1 8.1 8.1
78.1*** 78.0 84.5 86.4 88.5 93.5
68.4*** 79.4 78.4 81.7 85.7 89.6
10:07* 09:58
10: 16*** 1O:Ol
11.9 10.8
20.6*** 28.2
8.2 8.2
8.1 8.1
85.1* 80.2
80.7*** 74.1
1O:ll IO: 10
9.6* 13.6
21.7’ 26.1
8.2 8.3
8.1 8.1
85.5** 79.8
80.6** 74.2
10:04 10:04
10: 12 10:07
10.7 15.2
22.5 24.9
8.2 8.1
8.1 8.1
84.3** 75.4
80.1** 71.6
09:56*** 10:03 10: 16 10: 18
10:08* IO:11 IO:31 10:21
12.8 11.1 6.5 11.5
25.8
8.4** 8.2 8.2 8.0
8.1 8.1 7.8 8.0
80.3* 82.4 91.1 87.6
75.8** 80.6 92.6 82.7
Men
Women
Men
Women
Depressive symptoms
Lowest l/4 Highest l/4 Memory performance Lowest l/4 Highest l/4 Life satisfaction 5 6
7 8 9 10 Club member Yes
No
Attend weekly religious services 10:08** Yes No 09:58 Have confidante Yes
No Exercise level
Negligible Mild Moderate Vigorous
21.2 16.0 21.2
Life satisfaction is reoorted as the number of items resoondents answered in a direction indicating satisfaction. *p < 0.05; **p < 0.01; ***p < 0.001.
likely to report long sleep latencies (p’s < 0.001) and more likely to report feeling rested in the morning (p’s c 0.001) than were those with higher levels of symptoms. Similar relationships were observed with the measure of life satisfaction. Persons with better memory performance went to bed later (p’s < 0.001) and slept fewer hours (p’s < 0.05) than did those with poorer performance. Men (p’s < 0.05) and women (p’s < 0.001) who were members of clubs reported later bedtimes and were more likely to feel rested in the morning than non-members. Women club members were also less likely than non-members to report long sleep latencies (p < 0.001). Attendance at weekly religious services was associated with later bedtimes (p < O.Ol), decreased likelihood of long sleep latency (p < 0.05) and increased likelihood of feeling rested in the morning (p < 0.01) among men. Women who attended services weekly were less likely to report long sleep latencies (p < 0.05) and more likely to report feeling rested in the morning (p < 0.01) than were those who did not attend as frequently. Having a confidante was associated with increased likelihood of feeling rested among men (p < 0.01)
and women (p c 0.001). Lack of exercise was associated with earlier bedtimes among men (p < 0.001) and women (p < 0.05), increased sleep time among men (p < 0.01) and decreased likelihood of feeling rested in the morning among men (p < 0.05) and women (p < 0.01). No other differences were statistically significant. DISCUSSION
Sleep patterns undergo a variety of ageassociated changes [ 1,8, 11, 151, which may represent both “normal” and pathological changes [l, 51. In this paper we examined the sleep patterns reported by a population of community-dwelling rural elders, and found that altered sleep patterns were associated with physical, psychological, and social health and function. Previous epidemiologic studies have reported that from 10 to 50% of elderly persons complain of sleep problems, depending on the nature of the sleep problem under investigation. For example, Bixler et al. [4] reported that 40% of persons over the age of 50 had difficulty falling
Sleep Patterns in Rural Elders
asleep, and McGhie and Russell [9] reported that approximately 15% of persons aged 65 or older were frequently tired in the morning. Our findings that from 7585% of persons reported that they felt rested in the morning and that 2045% of respondents had sleep latencies exceeding 30 minutes are thus consistent with prior reports. This concordance is notable because previous epidemiologic studies of sleep patterns have used urban populations [4,8,9]. Our findings suggest that sleep problems may be as common among the rural as the urban elderly. The relationships between demographic variables and sleep patterns are similar to those which have been previously reported. Women reported more sleep problems than men [3,4,8,9]. Sleep problems increased with age [l, 3,4,8,9] and decreased with educational attainment [2-4,8,9]. The finding that women report higher levels of sleep problems may be in part a reflection of the high levels of depressive symptoms reported by this group of women [43]. Sleep disturbances have often been reported to be associated with depression [27-301, and higher levels of depressive symptoms were also associated with sleep disturbances in this study. The higher rates of sleep complaints among women may also simply be a reflection of the generally higher rates of health complaints typically seen in women. The relationship between educational attainment and sleep disturbances has also sometimes been attributed to affective problems and stress [4]. That is, persons of lower socioeconomic status have higher levels of psychiatric disturbance and report higher levels of stress than do those of higher socioeconomic status, and these factors may mediate the relationship between educational attainment and sleep problems. In addition, persons with lower educational attainment may receive less optimal medical. care and have health habits that result in poorer overall health status, thus increasing their risk of sleep disturbance. Like previous investigators, we found that sleep patterns were related to several aspects of health and functioning. Persons with higher levels of physical functional limitations reported earlier bedtimes than did less-limited persons, perhaps because of fatigue induced by their limitations. Lack of occupational or recreational activities may also contribute to earlier bedtimes, although this effect may be mediated by physical health and function. That is, in this
11
population, persons who are still working have lower age-adjusted rates of illness than do retirees [44]. Histories of emphysema, joint pain, and morning stiffness were associated with decreased likelihood of feeling rested in the morning. Breathing problems [23] and pain [24] may interfere with sleep and thus decrease its quality. Symptomatic treatment may therefore result in improved sleep. The relationship between self-perceived health status and sleep problems may be a function of both physical and psychological factors. That is, persons with poorer self-perceived health status tend to have more health problems and to report higher levels of depressive symptoms, either of which might contribute to sleep problems. Previous studies have reported that body mass index is associated with sleep characteristics such as percentage of REM sleep [45] and sleep apnea [32]. We generally failed to find associations between body mass index and the sleep parameters we included. Had we included items designed to screen specifically for sleep apnea (e.g. an item about excessively loud snoring), we might have obtained relationships with body mass index. Psychotropic drug use was associated with an increased likelihood of long sleep latency and a decreased likelihood of feeling rested in the morning. Because this report is cross-sectional, we cannot comment on the direction of the relationship. That is, it may be that persons with poorer sleep are more likely to take psychotropics and that their sleep will improve with continued medication use. Drugs may be taken for depression or anxiety, of which sleep disorders are a part. On the other hand, the sleep-promoting properties of anti-anxiety drugs may be considerably reduced after 2 weeks of consecutive use [46]. Thus some of the sleep complaints reported by persons using psychotropic drugs may be a result of ineffective treatment. Psychological health and function were also related to sleep patterns. As noted above, our findings are consistent with previous reports that higher levels of depressive symptoms were associated with higher levels of sleep problems [27-301. Clinically, sleep problems may be a common manifestation of depression in the elderly [471. Poorer life satisfaction was also associated with higher levels of sleep problems, possibly because lower levels of life satisfaction are associated with higher levels of depressive symptoms. The relationship between sleep and
12
EYASSUHABTE-GALIR et al.
memory performance may reflect several factors. Persons who recall fewer words on this test are generally older, less educated, and in poorer health than those who recall more words [48]. The observed relationship between sleep and memory performance may thus be mediated by any of these factors, or may represent independent manifestations of age-associated neurological changes. The relationship between sleep patterns and social recreational activity seems likely to be a function of both physical and psychological factors. Persons who are in better health and moods may be more likely to be active, and their sleep patterns may reflect their health status. Poorer sleep among persons reporting vigorous levels of exercise may indicate that they are not getting sufficient sleep. Several limitations should be noted in these analyses. We rely on self-reported sleep patterns which may be inaccurate [49]. Indeed, it has been suggested that persons who complain of poor sleep may be especially likely to overestimate their sleep latency and underestimate their total sleep time [50]. This would not necessarily void contrasts among groups, however. Moreover, the patterns of differences we found are consistent with other reports of the associations between sleep and health and functional status. It should also be remembered that sleep problems often come to the attention of clinicians as a result of patient complaints, and may never be documented with extensive psychophysiological sleep tests. It is thus important to understand the relationship between self-reported sleep problems and health in the general population. Self-reported medical conditions may also be inaccurate. In addition, because the analysis is cross-sectional, we are unable to make inferences about the direction of the relationships. This is especially important with regard to the analysis of the effects of psychotropic medications. Longitudinal studies of the elderly may also be particularly useful in determining the relationship between changes in health status and sleep patterns. This population-based survey of rural elders has demonstrated prevalence rates of sleep problems similar to those seen in urban elders. The relationships between sleep problems and physical and psychobehavioral health and functioning are similar to those reported in the clinical and experimental literature. Additional epidemiologic investigations using longitudinal designs and assessing health and function vari-
ables such as those reported here will further understanding of the natural history and therapeutic implications of sleep problems among the elderly. Acknowledgements-This research was supported by National Institute of Aging Contract NOl-AG-0-2106 and Grant AG-07094.
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Sleep Patterns in Rural Elders 18. Morgan K, Dallosso H, Ebrahim S, Arie T, Fentem PH. Characteristics of subjective insomnia in the elderly living at home. Age Ageing 1988; 17: l-7. 19. Partinen M, Putkonen PTS, Kaprio J, Koskenvuo M, Hilakivi I. Sleep disorders in relation to coronary heart disease. Aeta Med Scand 1982; 660: 69-83. 20. Dark DS, Pingleton SK, Kergy GR, Crabb JE, Gollub SB, Glatter TR, Dunn MI. Breathing pattern abnormalities and arterial oxygen desaturation during sleep in the congestive heart failure syndrome. Improvement following therapy. Chest 1987; 91: 833-836. 21. Erkinjuntti T, Partinen M, Sulkava R, Telakivi T, Salmi T, Tilvis R. Sleep apnea in multi-infarct dementia and Alxheimer’s disease. Sleep 1987; 10: 419425. 22 Komer E, Flooh E, Reinhart B, Wolf R, Ott E, Krenn W, Lechner H. Sleep alterations in ischemic stroke. Enr Nearol 1986; 25 (Suppl. 2): 104-110. 23. Klink M, Quan SF. Prevalence of reported sleep disturbances in a general adult population and their relationship to obstructive airways diseases. Cheat 1987; 91: 540-546. 24. Moldofsky H, Lue FA, Saskin P. Sleep and morning pain in primary osteoarthritis. J Rhenmatol 1987; 14: 124-128. 25. Swearer JM, Drachman DA, O’Donnell BF, Mitchell AL. Troublesome and disruptive behaviors in dementia. Relationship to diagnosis and disease severity. J Am Gerlatr Bee 1988; 36: 784790. 26. Barker JC, Mitteness LS. Nocturia in the elderly. GerontoIogIat 1988; 28: 99-104. 27. Kupfer DJ, Detre T, Harrow M. Relationship between sleep disorders and symptomatology. Arch Gen Psychiatry 1967; 17: 710-716. 28. Reynolds CF, Kupfer DJ. Sleep research in affective illness: State of the art circa 1987. Sleep 1987; 10: 199-215. 29. Van den Hoofdakker RH, Beersma DGM, Dijk DJ. Sleep disorders in depression. Em Neurol 1986; 25(Suppl. 2): 66-70. 30. Rodin J, McAvay G, Timko C. A longitudinal study of depressed mood and sleep disturbances in elderly adults. J Gerontok Psychol Scl 1988; 43: P45-P53. 31. Gislason T, Almqvist M, Eriksson G, Taube A, Boman G. Prevalence of sleep apnea syndrome among Swedish men-An epidemiological study. J Clln Epidemol 1988; 41: 571-576. 32. McGinty D. Sleep disorders in the elderly: Rationale for clinical awareness. Gerlatrles 1987; 42: 61-72. 33. Mosko SS, Dickel MJ, Paul T, LaTour T, Dhillon S, Ghanim A, Sassin JF. Sleep apnea and sleep-related periodic leg movements in community resident seniors. J Am Gerlatr See 1988; 36: 502-508. 34. Guilleminault C, Silvestri R. Aging, drugs, and sleep. In: Neurobiology of Aging, Vol. 3. U.S.A.: Ankho International; 1982.
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35. Thachil J, Zeller JR, Kochar MS. Hypersomnolence with beta-adrenergic blockers. Cheat 1987; 92: 943-944. 36. Lehmkuhl P, Prass D, Pichlmayr I. General anesthesia and postnarcotic sleep disorders. Nenropayehobblogy 1987; 18: 3742. 37. Bliwise DL, Bliwise NG, Partinen M, Pursley AM, Dement WC. Sleep apnea and mortality in an aged cohort. Am J PuhBe Health 1988; 78: 544-547. 38. National Institute on Aging. In: Comoni-Huntley J, Brock DW, Ostfeld AM, Taylor JO, Wallace RB, Eds. EstablIshed PopaIatiom for Epidemlologk Slndies of the Elderly: Resowee Data Book. Bethesda, Md: National Institutes of Health; 1986. 39. Rosow I, Breslau N. A Guttman health scale for the elderly. J Germ&l 1966; 21: 556559. 40. Radloff LS. The CESD Scale: A self-report depression scale for research in the general population. Appl Psycho1 Meas 1977; 1: 385401. 41. Wood V, Wylie M, Sheafor B. An analysis of a short self-report measure of life satisfaction: correlation with rater judgments. J. Gerontol 1969; 24: 465-469. 42. Mobily KE, Lemke JH, Drube GA, Wallace RB, Leslie DK. Relationship between exercise attitudes and participation among the rural elderly. Adapted Phys Activity Q 1987; 4: 38-50. 43. G’Hara MW, Kohout FJ, Wallace RB. Depression among the rural elderly. A study of prevalence and correlates. J New Ment Dia 1985; 173: 582-589. 44. Colsher PL, Dorfman LT, Wallace RB. Specitic health complaints and work-retirement status among the elderly. J Appl Gemntol 1988; 7: 485-503. 45. Adam K. Total and percentage REM sleep correlates with body weight in 36 middle-aged people. Sleep 1987; lo: 69-77. 46. Morgan K, Dallosso H, Ebrahim S, Arie T, Fentem PH. Prevalence, frequency, and duration of hypnotic drug use among the elderly living at home. Br Med J 1988; 296: 601602. 47. Gaylord SA, Zung WWK. Affective disorders among the aging. In: Carstensen LL, Edelstein BA, Eds. Handbook of CBaieaI Gerontology. New York: Pergamon Press; 1987; 76-95. 48. Colsher PL, Wallace RB. Memory performance in a population-based study of community-dwelling elders. Paper presented at the GerontologieaI society of America Meeting, November 1989, Minneapolis, Minn. 49. Weiss BL, McPartland RI, Kupfer DJ. Once more: The inaccuracy of non-EEG estimations of sleep. Am J. Psyehlatry 1973; 130: 1282-1285. 50. Adam K, Tomeny M, Oswald I. Physiological and psychological differences between good and poor sleepers. J. Psychiatry Res 1986; 20: 301-316.
0895-4356/91 $3.00+ 0.00 Copyright 0 1991Pcrgamon Pressplc
J m Epldem&l Vol.44,No. 1,pp.5-13,1991 Printedin Great Britain. All rights reserved
SLEEP PATTERNS IN RURAL ELDERS: HEALTH, AND PSYCHOBEHAVIORAL
DEMOGRAPHIC, CORRELATES
EYA~SUHABTE-GABR,’ROBERTB. WALLACE:PATRICIAL. COLSHER,~ JAMESR. HULBERT,~LON R. WHITERand IAN M. Se ‘HurleyMedicalCenter, MichiganState University,Flint, Michigan,‘Departmentof Preventive Medicineand EnvironmentalHealth, The Universityof Iowa, Iowa City, IA 52242,3National Instituteon Aging,Bethesda,Marylandand ‘Departmentof InternalMedicine,The Universityof Iowa, Iowa City, IA 52242,U.S.A. (Received
in revised form
20 July 1990)
Abstract-Altered sleep patterns, including changes in bedtime, sleep latency, total sleep time, and arising time, have been reported to occur with increasing age. We examine self-reported sleep patterns in a geographically-defined population (n = 3097)of persons aged 65 years and older. Sleep patterns were characterized according to demographic variables, clinical conditions, and physical, psychological, and social functioning. Sleep latency and total hours of sleep increased with age, and older respondents went to bed earlier. The percentage of respondents who reported feeling rested in the morning decreased with age. Women went to bed later, had longer sleep latency, and fewer hours of sleep than men, and were less likely to report feeling rested than men. Sleep patterns were also related to educational attainment, self-perceived health status, physical functional status, psychotropic drug use, alcohol use, depressive symptoms, life satisfaction, and social and recreational activity level. This population study suggests that sleep problems among the elderly are sometimes associated with treatable health conditions and modifiable behavioral and environmental characteristics. Geriatrics
Sleep patterns
Epidemiology
INTRODUCTION
of aging
There is some disagreement as to the extent to which age-related changes in sleep patterns represent normal as opposed to pathological changes [I, 51. A number of chronic conditions common among older persons are associated with change8 in sleep patterns, including myocardial infarction [ 191, congestive heart failure [20], stroke and multi-infarct dementia [21,22], chronic obstructive pulmonary disease [23], arthritis [24], urinary incontinence [25], Alzheimer’s disease [21,26] and depression [27-301. Sleep apnea and “restless-leg” syndrome [3 l-341 are associated with increasing age and sleep complaints. The use of various drugs, including psychotropic [34] and cardiovascular agents [34,35], is related to sleep disruptions. The elderly may be particularly vulnerable to
A number of age-associated changes in sleep patterns have been reported in both the clinical and experimental literature [ 1,2], including changes in bedtime [33, sleep latency [2,4-121, latency and amount of rapid eye movement (REM) sleep [2, 13, 141, time of awakening [2-4,7,11, 151, number of awakenings during the night [2,3,6-10, 16,171, total sleep time [2,3,9, 131, and sleep efficiency, or the ratio of the total sleep time to the total time in bed [2, 131. Older persons are also more likely than younger persons to have sleep-related complaints [l, 2,4,5,&g, 18]. From 10 to 50% of elderly persons report some type of sleep problem [4,5,8,9,18]. 5
EYASSUHABTE-GABR et al.
6
anesthesia- [36] and alcohol- [l] associated sleep disruption. Sleep disorders among the elderly are also associated with increased mortality risk L371. Because age-associated sleep disturbances are associated with morbidity and mortality, it is of importance to characterize their prevalence and understand the relation of sleep patterns to a variety of age-related health and psychobehavioral alterations. In this paper, we describe the sleep patterns in a geographically-defined cohort of community-dwelling elders, with these patterns characterized according to physical, psychological, and social health and function.
Further demographic characteristics of the respondents are given in Table 1. Less than half of the men had high school educations or greater, but more than half of the women did. Most men lived with someone else, although only about half of the women did. Most men were married, but most women were widowed. Most respondents were not employed. Questionnaire
Four sleep-related questions were used in the present study: (1) What time do you usually go to bed? (2) What time do you usually fall asleep? (3) What time do you usually get out of bed in the morning? (4) How often do you feel really rested when you wake up in the morning? Most of the time, some of the time, or rarely or never?
METHODS
Respondents
Respondents were participants in the Iowa 65 + Rural Health Study (RHS), a longitudinal population-based health survey of persons 65 years of age and older in two Iowa counties [38]. The RHS baseline survey which comprises this report was begun in 1982, and included 3673 persons, or approx. 80% of the target population. 3097 persons (84% of the cohort) completed the full in-person questionnaire on which these analyses were based, including 1155 men (mean age = 73.7 years) and 1942 women (mean age = 74.8 years). The remaining interviews were abbreviated or proxy interviews and will not be further considered.
Sleep latency was computed as the difference between time of falling asleep and bedtime, and respondents were classified as having latencies of more than 30 minutes, or 30 minutes or less. Respondents were classified as feeling rested most of the time or less than most of the time. Total sleep time was the difference between time of getting out of bed and time of falling asleep. Because of inconsistent data (e.g. falling asleep or waking up at a time prior to the reported bedtime), extreme times (e.g. reporting usually
Table 1. Demographic characteristics of respondents Men (%)
Women (%)
Total (%)
362 (31) 328 (28) 252 (22) 128(11) 85 (7)
510 (26) 508 (26) 443 (23) 299 (15) 182 (9)
872 (28) 836 (27) 695 (22) 427 (14) 267 (9)
685 (59) 283 (25) 182 (16)
883 (45) 616 (32) 430 (22)
1568 (51) 899 (29) 612 (20)
975 (84) 180(16)
986 (5 1) 956 (49)
1961 (63) 1136(37)
945 (82) 148 (13) 62 (5)
803 (41) 958 (49) 181 (9)
1748 (56) 1106 (36) 243 (8)
253 (22) 897 (78)
251 (13) 1683(87)
:2580 (84)
Age group (in yr)
6569 70-74 75-79 80-84 r84 Educational atlainment
Less than high school High school More than high school Residential status
With someone else Alone Marital status
Married Widowed Other* Work-retirement status?
Working Not working
504(16)
*Other marital status includes never married, divorced and separated. tworking includes working full time or part-time; not working includes retired, unemployed, and housewife.
1
Sleep Patterns in Rural Elders
having less than 2 or more than 14 hours of sleep), and missing data (e.g. “don’t know” responses), 139 persons were excluded from the analyses of usual bedtime, sleep latency, and total sleep time. The physical health and function variables included lifetime history of physician-diagnosed stroke, myocardial infarction, and emphysema, self-reported history during the past year of joint pain and morning stiffness, body mass index (weight divided by the square of height), use of psychotropic drugs (narcotics, sedatives, antipsychotics, and antianxiety agents) during the 2 weeks prior to interview, use of alcohol in the past month, and hospitalization during the past year. Gross physical function status was measured as limitations in self-reported ability to walk a half mile, walk up and down a fiight of stairs and do heavy housework [39]. Depressive symptoms were measured with a modified version of the Center for Epidemiologic Studies Depression Scale [40]. A life satisfaction scale [41] was also included. A test of free-recall memory, which consisted of 20 common one to two syllable nouns read to respondents, who then recalled as many as they could [38] was administered. Social activities/networks 11
measures included self-reported group membership, presence of a confidante, and attendance at religious services. Exercise levels were derived from a list of leisure activities [42]. Data analysis Mean bedtime, mean total sleep time, percentage of respondents with sleep latency over 30 minutes, and percentage of respondents feeling rested in the morning were obtained according to categories of demographic characteristics and physical, psychological, and social health and function. Analysis of variance was used to assess the statistical significance of differences in continuous variables between men and women, and among age groups for both genders. Chisquare analyses was used to assess the differences in categorical variables between men and women, and among age groups for both genders. Analyses of the health and functional characteristics were gender-specific and used age-adjusted values. Analysis of covariance (with age as covariate) was used to assess statistical significance for continuous variables, and logistic regression models were constructed for categorical variables, with age entered prior to the predictor of interest.
1
9.0-
6.63 2
6.6-
c, 8 'D c.n
6.4-
1
6.2.
2 6.0-
9’
7.61
I
65.69
70-74 ABe
75.79
60-64
65.69
65+
70-74
75-79
60-64
65+
Age Group (years)
Group (year@
m
90.0
.g 4
67.5
65.0-
LT
62.5-
= ;
60.0-
s.
es-es
70-74 Age
75-79
60-64
Group (years)
" a 3
77.5-
$
75.0'
I 65.69
70-74
75-79
WGrw(waW
Fig. 1. Gender- and age group-specific sleep patterns.
60-64
6S+
8
EYASSUHABTE-GABR et al. RESULTS
Figure 1 shows the age-specific mean bedtime, percentage of persons with sleep latency greater than 30 minutes, total hours of sleep, and percentage of persons feeling rested in the morning according to gender and age group. Women went to bed later than did men (unadjusted means = 10: 10 p.m. and 10:04p.m., respectively, p < O.Ol), slept fewer hours (unadjusted means = 8.1 and 8.2 hours, respectively, p < 0.05), were more likely to report sleep latencies exceeding 30 minutes (unadjusted percentages = 23.1 and 11.4, respectively, p < O.OOl), and were less likely to report feeling rested in the morning (unadjusted percentages = 78.6 and 82.9, respectively, p < 0.01). In gender-specific analyses, older men went to bed earlier (p < O.OOl), were more likely to have a sleep latency exceeding 30 minutes (p < 0.05), and reported more total hours of sleep (p < 0.001) than younger men. Older women went to bed earlier (p < 0.001) and slept longer (p < 0.05) than did younger women. No other differences were statistically significant. Table 2 shows sleep patterns according to demographic and employment characteristics. All values are age-adjusted. Men and women with more than a high school education went to bed later than less educated persons (p’s < 0.001) and women with more than a high school education got fewer hours of sleep than did less educated women (p < 0.05; not significant in men). Both men and women who lived alone went to bed later than did those who lived with others (p’s < 0.05 and 0.001, respectively) and women who lived alone reported fewer hours of sleep (p < 0.01). Women who worked got fewer hours of sleep (p < 0.001) and were more likely to report feeling rested in the morn-
ing (p < 0.05) than those who were not working. No other differences were statistically significant. Age-adjusted sleep patterns according to measures of physical health and function are shown in Table 3. Higher body mass index was associated with earlier mean bedtimes (p < 0.01) and more hours of sleep among women (p < 0.05), but was not significantly associated with any of the sleep parameters among men. History of heart attack (p < 0.001) and stroke (p < 0.05) were associated with decreased likelihood of feeling rested in the morning among women, and history of stroke was associated with increased likelihood of long sleep latency among men (p < 0.01). Emphysema, joint pain, and morning stiffness were all associated with decreased likelihood of feeling rested in the morning among both men and women (p’s < 0.001). Women who had been hospitalized in the year prior to interview reported earlier bedtimes (p < 0.05) and more hours of sleep (p < 0.05), were more likely to have long sleep latencies (p < 0.05) and less likely to feel rested in the morning (p < 0.001) than women who had not been hospitalized. The presence of physical functional limitations was associated with earlier bedtimes (significant in women only, p < O.Ol), increased sleep duration (p’s < O.Ol), increased likelihood of long sleep latency (p’s < O.OOl), and decreased likelihood of feeling rested in the morning (p’s -K 0.001). Men with relatively poor selfperceived health status reported earlier bedtimes (p < 0.05) and more hours of sleep (p < 0.05), but were less likely to report feeling rested in the morning (p < 0.001). Women with relatively poor self-perceived health status reported earlier bedtimes (p < O.OOl),were more likely to report long sleep latencies (p < 0.001) and less likely to
Table 2. Sleep patterns according to demographic characteristics Mean bedtime (p.m.)
% Sleep latency 130 min
Total night sleep (hr)
Men
Women
8.2* 8.0 8.0
81.8 84.3 85.5
71.6 19.4 79.3
8.1 8.2
8.0** 8.2
81.4 83.2
78.1 78.4
8.0 8.3
7 8*** 8:l
84.8 82.4
84.5* 77.7
Men
Women
Men
10:01*** 10: 16 IO:26
13.0 8.4 10.3
23.3 22.1 22.4
8.3 8.2 8.0
10: 13* to:02
10: 19*** IO:03
12.1 11.3
24.5 21.7
10:05 IO:03
10: 14 10: 11
7.9 12.3
20.7 23.4
Men Education High school
09: 55*** 10: 10 IO:25
Residential slam Alone With others Work stam Working Not working
*p < 0.05; **p < 0.01; ***p < 0.001.
Women
Women
% Feel rested
Sleep Patterns in Rural Elders Table 3. Sleep patterna
acco&ingto physical health and function % sleep later&y >3omm
Mean bedtime (p.m.) Men Body mass index Lower l/4 Upper l/4 Heart attack Yes No
9
Women
Total night sleep (hr)
Men
Women
Men
Women
% Feel rested Men
Women
10:02 1O:Ol
10: 15** 10:03
8.8 14.1
21.9 23.3
8.3 8.2
8.0* 8.2
82.2 78.5
18.3 79.4
10:09 10:02
10:07 10: 12
14.1 10.7
28.6 22.6
8.2 8.2
8.1 8.1
81.9 83.1
66.6*** 79.7
Stroke Yes No
09:56 10:04
1O:ll IO:11
21.8+* 10.6
24.5 23.0
8.4 8.2
8.2 8.1
77.1 83.3
68.4* 79.1
Emphysema Yes No
10:08 10:02
10:07 1O:ll
13.6 11.1
30.8 22.8
8.2 8.2
71.9*** 85.2
54.7*** 79.9
Joint pain Yes No
IO:04 10:04
10: 13 lo:08
12.2 10.0
23.7 21.6
8.2 8.2
8.1 8.1
79.5*** 89.5
74.9*** 85.9
10:04 10:02
10: 13 lo:08
12.3 10.5
23.7 22.4
8.2 8.2
8.1 8.1
77.6+** 88.1
73.3*** 84.7
(in past year) Yes No
1O:Ol 10:04
10:05* 10: 12
13.1 10.9
27.3, 22.1
8.3 8.2
8.1* 8.0
82.4 83.0
71.4*** 80.2
Physical function (Ho. limitations) Three Two One None
09:55 10:02 09:59 10:07
09:55** 10: 13 10: 16 1O:ll
19.8*** 20.2 13.7 9.0
33.8*** 27.5 24.6 20.2
8.7** 8.4 8.4 8.1
8.4** 8.2 8.1 8.0
67.9*** 72.3 79.1 87.2
57.0*** 63.3 78.3 84.9
Self-perceived health Poor Fair Good Excellent ’
09 : 59* 09:55 10:04 10: 13
09: 53*** 10:05 10: 10 10:22
18.5 12.5 11.3 8.8
40.7*** 30.0 21.2 16.6
8.5* 8.4 8.2 8.1
8.3 8.1 8.1 8.0
62.0*** 73.8 85.7 91.9
44.3*** 68.1 81.4 90.8
Morning stiffness Yes No
Hospitalization
*p < 0.05; **p < 0.01; ***p < 0.001.
report feeling rested in the morning (p < 0.001). No other differences were statistically significant. Table 4 shows the relationship between ageadjusted sleep patterns and substance use. Psychotropic drug use was associated with increased likelihood of long sleep latency among women (p < 0.001). Persons who used psychotropics were also less likely to report
that they felt rested in the morning (p’s c 0.001). Alcohol use was associated with later bedtimes among men (p < 0.05) and women (p < 0.001). The relationships between age-adjusted sleep patterns and psychological and social health and function are shown in Table 5. Persons with lower levels of depressive symptoms were less
Table 4. Sleep patterns according to substance use Mean bedtime (p.m.)
% Sleep latency > 30 min
Men
Women
Men
Psychotropic use Yes No
lo:oo IO:04
10:07 1O:ll
15.6 11.1
Alcohol use Yes No
10:08+ 09:59
10:22**; lo:08
11.8 11.0
Total night sleep (br)
% Feel rested
Men
Women
34.4*** 21.6
8.4 8.2
8.2 8.1
69.2*+* 83.6
64.4*** 80.1
22.7 23.2
8.2 8.3
8.0 8.1
84.5 81.5
81.5 77.7
Women
Psychotropic use refers to use in the 2 weeks prior to interview. Alcohol use refers to use in the month prior to interview. *p < 0.05; **p < 0.01; ***p < 0.001.
Men
Women
10
EYASSUHABTE-GABR et al. Table 5. Sleep patterns according to psychological and social health and function Mean bedtime (p.m.)
% Sleep latency > 30 min
Total night sleep fir) Men Women
% Feel rested
Men
Women
1O:ll’ lo:oo
IO: 14 lo:08
5.5*** 19.5
15.3*** 35.3
8.1 8.2
8.1 8.1
93.1*** 68.4
90.9*** 63.6
09: 58*** 10: 16
10:03*** lo:23
10.3 12.5
24.4 23. I
8.3* 8.1
8.2*** 7.9
81.0 84.0
80.0 79.0
09:54
10:07 1O:Ol 10:04 10:04 10: 12
10:07 10: 17 10: 14 IO:09 10: 16 10: 10
IO.92 14.7 9.1 8.0 11.7 8.2
28.2*** 21.3 25.1 19.3 18.3 18.4
8.4 8.1 8.3 8.2 8.2 8.3
8.1 8.0 8.1 8.1 8.1 8.1
78.1*** 78.0 84.5 86.4 88.5 93.5
68.4*** 79.4 78.4 81.7 85.7 89.6
10:07* 09:58
10: 16*** 1O:Ol
11.9 10.8
20.6*** 28.2
8.2 8.2
8.1 8.1
85.1* 80.2
80.7*** 74.1
1O:ll IO: 10
9.6* 13.6
21.7’ 26.1
8.2 8.3
8.1 8.1
85.5** 79.8
80.6** 74.2
10:04 10:04
10: 12 10:07
10.7 15.2
22.5 24.9
8.2 8.1
8.1 8.1
84.3** 75.4
80.1** 71.6
09:56*** 10:03 10: 16 10: 18
10:08* IO:11 IO:31 10:21
12.8 11.1 6.5 11.5
25.8
8.4** 8.2 8.2 8.0
8.1 8.1 7.8 8.0
80.3* 82.4 91.1 87.6
75.8** 80.6 92.6 82.7
Men
Women
Men
Women
Depressive symptoms
Lowest l/4 Highest l/4 Memory performance Lowest l/4 Highest l/4 Life satisfaction 5 6
7 8 9 10 Club member Yes
No
Attend weekly religious services 10:08** Yes No 09:58 Have confidante Yes
No Exercise level
Negligible Mild Moderate Vigorous
21.2 16.0 21.2
Life satisfaction is reoorted as the number of items resoondents answered in a direction indicating satisfaction. *p < 0.05; **p < 0.01; ***p < 0.001.
likely to report long sleep latencies (p’s < 0.001) and more likely to report feeling rested in the morning (p’s c 0.001) than were those with higher levels of symptoms. Similar relationships were observed with the measure of life satisfaction. Persons with better memory performance went to bed later (p’s < 0.001) and slept fewer hours (p’s < 0.05) than did those with poorer performance. Men (p’s < 0.05) and women (p’s < 0.001) who were members of clubs reported later bedtimes and were more likely to feel rested in the morning than non-members. Women club members were also less likely than non-members to report long sleep latencies (p < 0.001). Attendance at weekly religious services was associated with later bedtimes (p < O.Ol), decreased likelihood of long sleep latency (p < 0.05) and increased likelihood of feeling rested in the morning (p < 0.01) among men. Women who attended services weekly were less likely to report long sleep latencies (p < 0.05) and more likely to report feeling rested in the morning (p < 0.01) than were those who did not attend as frequently. Having a confidante was associated with increased likelihood of feeling rested among men (p < 0.01)
and women (p c 0.001). Lack of exercise was associated with earlier bedtimes among men (p < 0.001) and women (p < 0.05), increased sleep time among men (p < 0.01) and decreased likelihood of feeling rested in the morning among men (p < 0.05) and women (p < 0.01). No other differences were statistically significant. DISCUSSION
Sleep patterns undergo a variety of ageassociated changes [ 1,8, 11, 151, which may represent both “normal” and pathological changes [l, 51. In this paper we examined the sleep patterns reported by a population of community-dwelling rural elders, and found that altered sleep patterns were associated with physical, psychological, and social health and function. Previous epidemiologic studies have reported that from 10 to 50% of elderly persons complain of sleep problems, depending on the nature of the sleep problem under investigation. For example, Bixler et al. [4] reported that 40% of persons over the age of 50 had difficulty falling
Sleep Patterns in Rural Elders
asleep, and McGhie and Russell [9] reported that approximately 15% of persons aged 65 or older were frequently tired in the morning. Our findings that from 7585% of persons reported that they felt rested in the morning and that 2045% of respondents had sleep latencies exceeding 30 minutes are thus consistent with prior reports. This concordance is notable because previous epidemiologic studies of sleep patterns have used urban populations [4,8,9]. Our findings suggest that sleep problems may be as common among the rural as the urban elderly. The relationships between demographic variables and sleep patterns are similar to those which have been previously reported. Women reported more sleep problems than men [3,4,8,9]. Sleep problems increased with age [l, 3,4,8,9] and decreased with educational attainment [2-4,8,9]. The finding that women report higher levels of sleep problems may be in part a reflection of the high levels of depressive symptoms reported by this group of women [43]. Sleep disturbances have often been reported to be associated with depression [27-301, and higher levels of depressive symptoms were also associated with sleep disturbances in this study. The higher rates of sleep complaints among women may also simply be a reflection of the generally higher rates of health complaints typically seen in women. The relationship between educational attainment and sleep disturbances has also sometimes been attributed to affective problems and stress [4]. That is, persons of lower socioeconomic status have higher levels of psychiatric disturbance and report higher levels of stress than do those of higher socioeconomic status, and these factors may mediate the relationship between educational attainment and sleep problems. In addition, persons with lower educational attainment may receive less optimal medical. care and have health habits that result in poorer overall health status, thus increasing their risk of sleep disturbance. Like previous investigators, we found that sleep patterns were related to several aspects of health and functioning. Persons with higher levels of physical functional limitations reported earlier bedtimes than did less-limited persons, perhaps because of fatigue induced by their limitations. Lack of occupational or recreational activities may also contribute to earlier bedtimes, although this effect may be mediated by physical health and function. That is, in this
11
population, persons who are still working have lower age-adjusted rates of illness than do retirees [44]. Histories of emphysema, joint pain, and morning stiffness were associated with decreased likelihood of feeling rested in the morning. Breathing problems [23] and pain [24] may interfere with sleep and thus decrease its quality. Symptomatic treatment may therefore result in improved sleep. The relationship between self-perceived health status and sleep problems may be a function of both physical and psychological factors. That is, persons with poorer self-perceived health status tend to have more health problems and to report higher levels of depressive symptoms, either of which might contribute to sleep problems. Previous studies have reported that body mass index is associated with sleep characteristics such as percentage of REM sleep [45] and sleep apnea [32]. We generally failed to find associations between body mass index and the sleep parameters we included. Had we included items designed to screen specifically for sleep apnea (e.g. an item about excessively loud snoring), we might have obtained relationships with body mass index. Psychotropic drug use was associated with an increased likelihood of long sleep latency and a decreased likelihood of feeling rested in the morning. Because this report is cross-sectional, we cannot comment on the direction of the relationship. That is, it may be that persons with poorer sleep are more likely to take psychotropics and that their sleep will improve with continued medication use. Drugs may be taken for depression or anxiety, of which sleep disorders are a part. On the other hand, the sleep-promoting properties of anti-anxiety drugs may be considerably reduced after 2 weeks of consecutive use [46]. Thus some of the sleep complaints reported by persons using psychotropic drugs may be a result of ineffective treatment. Psychological health and function were also related to sleep patterns. As noted above, our findings are consistent with previous reports that higher levels of depressive symptoms were associated with higher levels of sleep problems [27-301. Clinically, sleep problems may be a common manifestation of depression in the elderly [471. Poorer life satisfaction was also associated with higher levels of sleep problems, possibly because lower levels of life satisfaction are associated with higher levels of depressive symptoms. The relationship between sleep and
12
EYASSUHABTE-GALIR et al.
memory performance may reflect several factors. Persons who recall fewer words on this test are generally older, less educated, and in poorer health than those who recall more words [48]. The observed relationship between sleep and memory performance may thus be mediated by any of these factors, or may represent independent manifestations of age-associated neurological changes. The relationship between sleep patterns and social recreational activity seems likely to be a function of both physical and psychological factors. Persons who are in better health and moods may be more likely to be active, and their sleep patterns may reflect their health status. Poorer sleep among persons reporting vigorous levels of exercise may indicate that they are not getting sufficient sleep. Several limitations should be noted in these analyses. We rely on self-reported sleep patterns which may be inaccurate [49]. Indeed, it has been suggested that persons who complain of poor sleep may be especially likely to overestimate their sleep latency and underestimate their total sleep time [50]. This would not necessarily void contrasts among groups, however. Moreover, the patterns of differences we found are consistent with other reports of the associations between sleep and health and functional status. It should also be remembered that sleep problems often come to the attention of clinicians as a result of patient complaints, and may never be documented with extensive psychophysiological sleep tests. It is thus important to understand the relationship between self-reported sleep problems and health in the general population. Self-reported medical conditions may also be inaccurate. In addition, because the analysis is cross-sectional, we are unable to make inferences about the direction of the relationships. This is especially important with regard to the analysis of the effects of psychotropic medications. Longitudinal studies of the elderly may also be particularly useful in determining the relationship between changes in health status and sleep patterns. This population-based survey of rural elders has demonstrated prevalence rates of sleep problems similar to those seen in urban elders. The relationships between sleep problems and physical and psychobehavioral health and functioning are similar to those reported in the clinical and experimental literature. Additional epidemiologic investigations using longitudinal designs and assessing health and function vari-
ables such as those reported here will further understanding of the natural history and therapeutic implications of sleep problems among the elderly. Acknowledgements-This research was supported by National Institute of Aging Contract NOl-AG-0-2106 and Grant AG-07094.
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