Psychological correlates of self-reported functional limitation in patients with ankylosing spondylitis.
BACKGROUND
Functional status is an integral component of health-related quality of life in patients with ankylosing spondylitis (AS). The purpose of this study was to investigate the role of psychological variables in self-reported functional limitation in patients with AS, while controlling for demographic and medical variables.


METHODS
294 AS patients meeting modified New York Criteria completed psychological measures evaluating depression, resilience, active and passive coping, internality and helplessness at the baseline visit. Demographic, clinical, and radiologic data were also collected. Univariate and multivariate analyses were completed to determine the strength of correlation of psychological variables with functional limitation, as measured by the Bath AS Functional Index (BASFI).


RESULTS
In the multivariate regression analysis, the psychological variables contributed significantly to the variance in BASFI scores, adding an additional 24% to the overall R-square beyond that accounted by demographic and medical variables (R-square 32%), resulting in a final R-square of 56%. Specifically, arthritis helplessness, depression and passive coping beside age, ESR and the Bath AS Radiograph Index accounted for a significant portion of the variance in BASFI scores in the final model.


CONCLUSIONS
Arthritis helplessness, depression, and passive coping accounted for significant variability in self-reported functional limitation beyond demographic and clinical variables in patients with AS. Psychological health should be examined and accounted for when assessing functional status in the AS patients.
Brionez
Tamar F
TF
Department of Medicine, Division of Rheumatology, University of Texas-Houston, 6431 Fannin, Houston, Texas 77030, USA. jbrionez@gmail.com
Assassi
Shervin
S
Reveille
John D
JD
Learch
Thomas J
TJ
Diekman
Laura
L
Ward
Michael M
MM
Davis
John C
JC
Weisman
Michael H
MH
Nicassio
Perry
P
D000203:Activities of Daily Living / Q000523:psychology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology*; D012720:Severity of Illness Index; D013167:Spondylitis, Ankylosing / Q000523:psychology*