Perruccio AV, Power JD, Badley EM. Arthritis onset and worsening
self-rated health: the role of pain and activity limitations;
A longitudinal evaluation of the role of pain and activity limitation.
Arthritis Care Res. 2005 Aug;53(4):57-77. [Pub
Med ID 16082649]
Objective
To longitudinally explore the hypothesized role of worsening pain and development
of activity limitations as mediators in the relationship between
arthritis onset and worsening self-rated health (SRH).
[more…]
One of the most significant predictors of poor self-rated health is the
presence of chronic conditions. Pain is a common reason for seeking
medical care and is associated with poor self-rated health. Studies indicate
that chronic pain seems to relate to poor health more strongly than chronic
diseases or age, and the significant association persists even
when sociodemographic and relevant health factors are considered.
Methods
Data was obtained from the 1998/1999 and 2000/2001 cycles of the population-based
Canadian longitudinal National Population Health Survey (n = 10,859;
ages ≥18; response rate: time 1 = 81.6%, time 2 = 89.2%). Respondents were
asked about chronic conditions, pain, activity limitations, and self-perceived
health; change over time was assessed. Change in effect of arthritis onset
on worsening SRH upon considering potential mediators was assessed through
multivariate logistic regression, controlling for sociodemographic characteristics
and onset of other conditions.
[more…]
To evaluate self-rated health, respondents were asked, “In general,
would you say your health is: Excellent? Very good? Good? Fair?
Poor?” A dichotomous variable was created to indicate worse SRH at follow-up.
Worse was defined as a change in the following direction: excellent/very
good to good to fair/poor. Respondents were asked if a physical condition
or health problem limited the type or amount of activity they could do
at home, school, work, or in other activities such as leisure time activities,
or whether they had any long-term disabilities or handicaps.
A positive response to any one of the above was defined as having an activity
limitation. Development of an activity limitation was defined as a change
from a negative to a positive response over time.
Results
Worsening pain fully explained the effect of arthritis onset on worsening
SRH; a portion of the effect of worsening pain was mediated by
the development of activity limitation. Residual direct effect of arthritis
onset was statistically insignificant. Worsening pain and development of
activity limitations also mediated a portion of the effects of onset of
other chronic conditions but to a lesser extent than arthritis onset.
[more…]
See Tables 1 and 2 for more details.
Conclusion
This is the first study to examine these relationships longitudinally.
Identifying the role of mediators is necessary if target areas
of prevention and/or management are sought, either at the individual or
population level. Our results indicate that the development of arthritis
has a significant impact on worsening SRH. Pain and development of activity
limitations fully account for the relationship between arthritis onset and
worsening SRH. High priority should be placed on prevention and management
strategies for pain among people with arthritis.
[more…]
Pain seems to have the largest mediating effect on new disabling conditions.
This may be related to the fact that back problems are the most
frequent condition in this group. To some extent, the findings from the
study explain why there appears to be a stronger relationship between
pain and poor health status than between chronic diseases and poor health
status. Since worsening pain fully explained the effects of developing
arthritis on worsening self reported health and that the effects of pain
were further mediated by the development of activity limitations, this
suggests that it is these symptoms rather than arthritis as such that
were associated with worse SRH. This has definite implications for the
clinical management of this condition.
List of Tables and Figures (in the publication)
- Figure 1. Hypothesized conceptual model (A), main effect models
(B), and mediated models (C). All estimates are adjusted for
age, sex, education, income, and all new conditions.
- Table 1. Prevalence of selected characteristics in the Canadian
population at baseline, 1998/2000 Canadian longitudinal National
Population Health Survey.
- Table 2. Percentage distribution of self-rated health (SRH)
status by sociodemographic characteristics in the Canadian population
using data from the 1998/2000 Canadian longitudinal National
Population Health Survey.
- Table 3. Percentage of people who developed specified outcomes,
and also reported developing additional outcomes, from the 1998/2000
Canadian longitudinal National Population Health Survey.
- Table 4. Results from the main effects models for reporting
specified outcome at follow-up, 1998/2000 Canadian longitudinal
National Population Health Survey.
- Table 5. Results from the mediated models for reporting specified
outcome at followup, 1998/2000 Canadian longitudinal National
Population Health Survey.
- Table 6. Percentage of decrease in the effect of conditions
on outcomes having accounted for worse pain and/or new activity
limitation, 1998/2000 Canadian longitudinal National Population
Health Survey.
Selected Tables from the Publication (with interpretation)
Table 1. Prevalence of selected characteristics in the Canadian population
at baseline, 1998/2000 Canadian longitudinal National Population Health
Survey.
| Variable |
% Prevalence at baseline (95% CI) |
|
|
|
| Self-rated health |
|
|
Fair/Poor |
9.1 (8.34-9.88) |
|
Good |
26.7 (25.55-27.84) |
|
Excellent/Very good |
64.2 (62.98-65.42) |
| Usual intensity of pain/discomfort |
|
|
No pain |
85.8 (85.02-86.65) |
|
Mild |
4.4 (3.88-4.92) |
|
Moderate |
8.1 (7.42-8.73) |
|
Severe |
1.7 (1.42-1.96) |
| With activity limitation |
18.9 (17.90-19.98) |
| With arthritis |
17.0 (16.18-17.8) |
| ≥ 1 non-disabling condition |
47.2 (45.91-48.43) |
| ≥ 1 disabling condition |
19.0 (18.00-20.06) |
| ≥ 1 life-threatening condition |
9.0 (8.30-9.67) |
Table 1 presents the prevalence of characteristics of interest at baseline.
Approximately 10% of respondents reported their health as being
fair/poor, 15% reported some level of pain, and 17% reported the
presence of arthritis. Almost 50% reported at least one non-disabling
condition, and 20% reported at least one disabling condition. At follow-up,
a greater proportion of individuals reporting worse SRH were older,
of lower income, and lower education levels than those without worse SRH
(see Table 2 below).
Table 2. Distribution of socio-demographic characteristics by self-rated
health status in the Canadian population, 1998/2000 Canadian longitudinal
National Population Health Survey.
| Variable |
Worse SRH
% Distribution |
No worse SRHi
% Distribution |
| Age |
|
|
|
18-34 |
26.7 |
31.9 |
|
35-44 |
20.9 |
24.9 |
|
45-54 |
16.9 |
18.4 |
|
55-64 |
12.3 |
11.9 |
|
65-74 |
12.4 |
8.0 |
|
75+ |
10.9 |
5.0 |
| Sex |
|
|
|
Men |
46.3 |
49.2 |
|
Women |
53.7 |
50.8 |
| Income adequacy |
|
|
|
Lowest |
14.3 |
10.6 |
|
Lower-middle |
26.8 |
24.0 |
|
Upper-middle |
34.9 |
35.6 |
|
Highest |
18.0 |
23.6 |
|
Non-stated |
6.0 |
6.2 |
| Education level |
|
|
|
Less than secondary |
26.3 |
20.1 |
|
Secondary |
16.8 |
15.0 |
|
Some post-secondary |
28.6 |
28.7 |
|
Post-secondary |
28.4 |
36.2 |
Supplementary Tables (with interpretation)
No supplementary information is available for this paper.
- “no worse” SRH indicates that self-rated health did not
worsen over time.
