Power JD, Perruccio AV, Badley EM. Pain as a mediator of sleep
problems in arthritis and other chronic conditions. Arthritis Rheum.
2005 Dec 7;53(6):911-919. [Pub
Med ID 16342098]
Objective
To examine the associations between arthritis and insomnia symptoms and
unrefreshing sleep, as well as the role of pain as a mediator of these relationships.
[more…]
There is growing awareness that sleep is affected as a consequence of
physical health, with poor health precipitating or contributing to existing
sleep difficulties. Arthritis has been found to be associated with sleep
problems in a number of studies, although these studies have been mainly
conducted on small patient populations and have tended to focus on inflammatory
forms of the disease. Insomnia is generally defined as an impression of
inadequate sleep associated with deficits in initiating or maintaining
sleep and is the most common sleep difficulty in the general population.
Unrefreshing or unrestorative sleep refers to lack of satisfaction with
the sleep experience and is associated with a sense of being unrefreshed
after sleep. This specific sleep problem has not generally been the focus
of much research, particularly relative to insomnia.
Methods
Analyses were conducted on the cross-sectional, nationally representative,
weighted sample of adults ≥18 years of age (n = 118,336) in the 2000/2001
Canadian Community Health Survey. Four logistic regression models
were estimated for each sleep problem (model 1: arthritis only; model 2:
model 1 + sociodemographic characteristics, lifestyle factors, and other
chronic conditions; model 3: model 2 + mental health [stress, depression];
and model 4: model 3 + pain). Mediation by pain was quantified by the percentage
change in the effect of arthritis on a particular sleep problem by comparing
models 3 and 4.
[more…]
The 2000-2001 Canadian Community Health Survey is a cross-sectional
survey conducted by Statistics Canada and collects self-reported
information related to the health status, service use, and health determinants
of Canadians. It is the first major Canadian survey in 10 years
to incorporate questions on sleep difficulties.
Results
The prevalence of insomnia symptoms and unrefreshing sleep in persons
with arthritis was 24.8% and 11.9%, respectively. These estimates
are twice as high as those for persons without arthritis. In multivariate
regression analyses, the addition of pain decreased the effect
of arthritis by 53% (insomnia symptoms) and 64% (unrefreshing sleep).
The effect of arthritis was still statistically significant in these models,
suggesting that pain is a partial mediator of these relationships.
[more…]
See Table 1 and Figure 1 for more details.
Conclusion
Insomnia symptoms and unrefreshing sleep affect a considerable proportion
of individuals with arthritis. Pain mediates a substantial amount
of the relationship between arthritis and sleep problems. Better
pain management could significantly improve sleep in individuals with arthritis.
[more…]
Pain is a symptom of many of the conditions we included as control variables,
and not surprisingly, pain also appeared to play a substantial
mediating role in the effects of several of these conditions.
One of the strongest mediating effects of pain was observed for
other musculoskeletal conditions [fibromyalgia, back problems].
Adjustment for pain reduced the effect of musculoskeletal conditions
on unrefreshing sleep and insomnia symptoms by 57% and 48% respectively.
It should be noted that at least some of the individuals reporting
back problems are likely to actually have arthritis. As for our
findings for arthritis and other musculoskeletal conditions,
pain generally appeared to play a somewhat larger role in mediating
the effects of chronic conditions on unrefreshing sleep than
on insomnia symptoms.
List of Tables and Figures (in the publication)
- Table 1. Prevalence estimates of arthritis, sleep problems,
and pain in the Canadian adult population, Canadian Community
Health Survey 2000/2001.
- Figure 1. Prevalence of sleep problems by arthritis status
and pain severity in the Canadian adult population, Canadian
Community Health Survey 2000/2001.
- Table 2. Logistic regression models: predictors of insomnia
symptoms in the Canadian adult population, Canadian Community
health Survey 2000/2001.
- Table 3. Logistic regression models: predictors of unrefreshing
sleep in the Canadian adult population, Canadian Community Health
Survey 2000/2001.
Selected Tables from the Publication (with interpretation)
Table 1. Prevalence estimates of arthritis, sleep problems, and pain in
the Canadian adult population, Canadian Community Health Survey 2000/01.
|
|
Percentage (95% confidence interval) |
| Characteristic |
Number (in thousands) |
All Subjects |
With Arthritis* |
Without Arthritis |
| Arthritis |
3,914 |
16.8 (16.5-17.1) |
- |
- |
| Insomnia Symptoms |
3,032 |
14.1 (13.8-14.3) |
24.8 (24.1-25.6) |
10.6 (10.3-10.9) |
| Unrefreshing Sleep |
1,660 |
7.7 (7.5-7.9) |
11.9 (11.3-12.5) |
6.1 (5.9-6.4) |
| Pain |
|
|
|
|
|
Mild |
1,242 |
5.3 (5.1-5.5) |
10.7 (10.1-11.3) |
4.2 (4.0-4.4) |
|
Moderate |
2,155 |
9.2 (9.0-9.5) |
25.3 (24.5-26.0) |
6.0 (5.8-6.2) |
|
| Severe
| 668 |
2.9 (2.7-3.0) |
9.6 (9.0-10.3) |
1.5 (1.4-1.6) |
- * p ‹ 0.001 for all characteristics comparing subjects with
arthritis and those without arthritis.
This table shows the prevalence of arthritis was 16.8% affecting 3.9 million
Canadians ages ≥ 18 years. Slightly more than 17% of Canadians reported
usually experiencing some level of pain, with 9.2% and 2.9% reporting
that pain was moderate and severe, respectively. Prevalence estimates for
insomnia symptoms and unrefreshing sleep were 14.1% and 7.7% respectively.
Significantly higher proportions of individuals with arthritis reported
pain and both of the sleep problems than did subjects without arthritis
(Table 2). Approximately one-quarter of persons with arthritis reported
insomnia symptoms, more than twice the proportion of those without arthritis.
Approximately 12% of individuals with arthritis reported experiencing unrefreshing
sleep, again approximately twice the proportion of those without arthritis.
Figure 1: Prevalence of sleep problems by arthritis status and pain severity
in the Canadian adult population, Canadian Community Health Survey 2000/01.
We can see in Figure 1 that the prevalence of both insomnia symptoms and
unrefreshing sleep increased with increasing pain severity in persons
with and without arthritis. However, individuals with arthritis had a higher
prevalence of sleep difficulties, particularly insomnia symptoms,
at each pain level, with the exception of those with mild pain reporting
unrefreshing sleep.
Supplementary Tables (with interpretation)
No supplementary information is available for this paper.
