Download Figure 1. The Symptom Intensity Scale: A Measure

The Association of Fibromyalgia Symptoms with SLE Outcome and Diagnosis
1
Katz ,
2
Wolfe ,
2
Michaud ,
3
Cooney
Robert S.
Frederick
Kaleb
Carisa M.
1Rush University Medical Center, Chicago, IL; 2National Data Bank for Rheumatic Diseases, Wichita, KS;
3Oklahoma Medical Research Foundation, Oklahoma City, OK
Abstract
PURPOSE. To describe the association between fibromyalgia
symptoms and systemic lupus erythematosus (SLE) diagnosis and
outcome.
Figure 1. The Symptom Intensity Scale:
A Measure of Fibromyalgianess
.8
Proportion with symptom
METHODS. We studied 421 patients with SLE diagnosed by
rheumatologists and compared them to 10,492 patients with other
rheumatic disorders. Fibromyalgia was identified using survey
fibromyalgia criteria (VAS fatigue score >= 6 and a Regional Pain
Score (RPS) >= 8) and further analyzed as a continuous variable as the
Symptom Intensification scale (SIS) (fatigue + (RPS/2))/2. We used the
4 quartiles of the SI Scale to classify patients according to the degree of
fibromyalgia symptoms. All patients in Quartile 4 and 33% of patients
in Quartiles 3 satisfy fibromyalgia criteria. Quality of life (QOL) was
determined using the EQ-5D utility.
.6
Low Platelets
Low WBC
Pleurisy
Raynauds
Oral Ulcers
Rash
Photosensitivity
Purpura
.4
.2
Table 1. Quartiles of Fibromyalgia Symptom Intensity and SLE Outcomes
Fibromyalgianess Quartile
1
2
3
4
Satisfies Fibromyalgia Criteria (%)
0
0
33
93
Vasculitis (%)
15
16
18
20
Renal Disease (%)
36
30
34
39
HCQ (%)
59
66
54
59
Prednisone (%)
47
51
49
56
SLE ROS Count
1.5
2.2
3.0
3.9
Pain (0-10)
1.5
3.4
4.9
7.3
Work Disability (%)
13
32
37
55
EQ-5D Utility (0-1)
0.87 0.76 0.68 0.52
Medical costs ($US)
3,002 3,732 4,282 7,770
Total
31
18
35
60
50
2.6
4.2
33
0.72
4,652
•31% of patients with
SLE and 19% of patients
without SLE satisfied
survey fibromyalgia
criteria
•Fibromyalgia (characteristics) exists as a continuum among SLE patients rather than
as a dichotomous condition
Proportion with symptom
RESULTS. Using multivariate regression, we determined that
photosensitivity Raynaud’s, rash, oral ulcers, purpura, pleurisy, low
WBC, low platelet count, vasculitis, renal disease, age sex, ethnicity,
hydroxychloroquine and prednisone best separated SLE and non-SLE
patients (area under ROC = .91); and the 8 symptoms from a review of
systems (ROS) described above had a ROC curve of 0.79 alone.
Additionally, the 8 ROS variable were summed to make a Lupus ROS
scale (0-8). Among SLE patients, 31% satisfied FM criteria, 18% had
vasculitis and 35% had renal disease (Table 1). We examined the
relation between lupus symptoms and degree of fibromyalgia in Figure
1 where it can be seen that SLE symptoms increased stepwise in each
quartile of the SI scale. Similarly, Table 1 showed strong and
statistically significant associations between the SLE symptom scale,
VAS pain, Social Security disability, QOL and direct medical costs; by
contrast, there were weak or no associations with vasculitis, renal
disease and SLE treatment.
Association of SLE predictors with fibromyalgia in 437 SLE patients
0
1
2
3
4
Quartiles of fibromyalgia intensity
Comparison of SLE symptoms in Patients with and without SLE
.8
.6
•There is no clear separation of fibromyalgia status at any level of the SI scale.
CONCLUSIONS. Fibromyalgia (characteristics) exists as a continuum
among SLE patients rather than as a dichotomous condition, and there
is no clear separation of fibromyalgia status at any level of the SI scale.
Fibromyalgia symptom intensity reflects the total burden of SLE illness,
as manifested by pain intensity, QOL and medical costs. This
association is similar to what is seen in all other rheumatic disorders
and suggests that fibromyalgia diagnosis and symptoms are a response
to illness severity
•Fibromyalgia symptom intensity reflects the total burden of SLE illness, as manifested
by pain intensity, QOL and medical costs. This association is similar to what is seen in
all other rheumatic disorders and suggests that fibromyalgia diagnosis and symptoms
are a response to illness severity
Low Platelets
Low WBC
Pleurisy
Raynauds
Oral Ulcers
Rash
Photosensitivity
Purpura
.4
.2
References
F. Wolfe and J. J. Rasker. The symptom intensity (SI) scale,
fibromyalgia, and the meaning of fibromyalgia-like symptoms. J
Rheumatol. November 2006.
R. S. Katz, F. Wolfe, and K. Michaud. Fibromyalgia diagnosis: A
comparison of clinical, survey, and American College of
Rheumatology criteria. Arthritis Rheum. 54 (1):169-176, 2006.
0
Not SLE
SLE
Not Fibromyalgia
Not SLE
SLE
Fibromyalgia