Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Performance of Different Criteria Sets for Inflammatory Back Pain in Patients with Axial Spondyloarthritis with and without Radiographic Sacroiliitis.

Solmaz3,  Dilek, Akar3,  Servet, Gunduz3,  Ozgul, Yuksel1,  Feride, Can3,  Gercek, Gerdan3,  Vedat, Akkoc2,  Yesim

Internal Medicine, Dokuz Eylul University Faculty of Medicine
Physical Therapy and Rehabilitation, Ege University Faculty of Medicine
Rheumatology, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey

Background:

The most prominent clinical feature of axial spondyloarthritis (SpA), is inflammatory back pain (IBP). Therefore it is of crucial impaortance to recognize inflammatory back pain for an early diagnosis of axial SpA, including ankylosing spondylitis (AS). Up to now several criteria sets have been proposed to define inflammatory back pain (IBP). Assessment of SpondyloArthritis International Society (ASAS) has just recently published new criteria set for diagnosing IBP. In the present study we evaluated the performance of the new ASAS criteria for IBP in comparison to Calin and Berlin criteria in patients with axial SpA using a control group of patients with chronic mechanical low back pain (MLBP).

Patients and Methods:

The study sample included a total of 214 patients [117 male (54,7%); mean age42,6±12,2] with a diagnosis axial SpA based on clinical and radiologic findings and 44 patients with a diagnosis of chronic (>3 moths) MLBP based upon the treating physician's clinical judgment (MLBP group). Among patients with axial SpA, 70 patients had active sacroiliitis (SI) on MRI as defined by ASAS (SI on MRI group) and 144 patients had radiographic SI as defined by the modified New York criteria (AS group). A face to face interview by using a standardized questionnaire addressing all the components of inflammatory back pain included in Calin, Berlin and new ASAS criteria sets was performed by the same trained physicain. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) were measured. Data about HLA B27 status, erythrocyte sedimentation rate and C reactive protein (CRP) levels were obtained from the patients charts if available.

Results:

There were significantly more male patients (p<0,001) in the AS group (%66) than in the SI on MR (%31,4) and also than in the MLBP group (%36,4). Some demographic and clinical features in the patient groups are shown in Table 1.

Among the criteria sets, Calin criteria showed the best sensitivity (92%), and Berlin criteria showed the best specificity (84%) in the differentiation of inflammatory back pain from chronic mechanical back pain. If the morning stiffness component of Calin's criteria set was defined as longer than30 minutes, the specificity improved (75%), but at a price of loss in sensitivity (84,5%). The performance of different criteria sets in different patient groups are shown in Table 2.

Conclusion:

New ASAS criteria for IBP did not seem to perform better in differentiating IBP from chronic mechanical back pain, than the existing criteria sets in patients followed at a rheumatology outpatient clinic.

Table 1. Demographic and clinical features in the study groups

 AS group (n = 144)SI on MRI group (n = 70)MLBP group (n = 44)
Males, n (%)95 (66)22 (31)16 (36,4)
Age, mean ± SD42,3 ± 11,643,1 ± 12,743,6 ± 11,6
Age at onset of back pain, mean ± SD24,7 ± 7,427,8 ± 7,429,7 ± 9,6
Education Level, mean ± SD (years)9,5 ± 3,810,4 ± 4,29,0 ± 4,2
BASDAI, mean ± SD3,4 ± 2,24,8 ± 2,63,2 ± 2,4
BASFI, mean ± SD2,7 ± 2,63,1 ± 2,42,2 ± 2,0
CRP, mean ± SD12,9 ± 14,58,2 ± 14,33,6 ± 3,7
HLA-B27 positivity72%36%7–11%*
*HLA-B27 positivity reported in the general Turkish population in previous publications.

Table 2. Performance of different criteria sets in different patient groups

 CalinCalin 30BerlinASAS
 ASSI on MRIASSI on MRIASSI on MRIASSI on MRI
Sensitivity (%)95,188,588,075,774,378,577,072,8
Specificity (%)50,050,075,075,084,084,072,772,7
+LR (%)1,91,73,53,04,64,92,82,6
-LR (%)0,090,20,10,20,30,20,30,3
Odds Ratio19,57,7249,315,219,38,97,1

To cite this abstract, please use the following information:
Solmaz, Dilek, Akar, Servet, Gunduz, Ozgul, Yuksel, Feride, Can, Gercek, Gerdan, Vedat, et al; Performance of Different Criteria Sets for Inflammatory Back Pain in Patients with Axial Spondyloarthritis with and without Radiographic Sacroiliitis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :544
DOI: 10.1002/art.28313

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