Predictive factors of work disability in rheumatoid arthritis: a systematic literature review.
BACKGROUND
Work disability-a common outcome of rheumatoid arthritis (RA)-is a societal (for example, financial costs) and individual problem (for example, loss of status, income, social support, and distraction from pain and distress). Until now, factors that predict work disability in RA have not been systematically reviewed.


OBJECTIVE
To determine predictive factors of work disability in RA as reported in the literature.


METHODS
A systematic literature search in Cinahl (1988-2004), Embase (1988-2004), and Medline (1989-2004) was followed by the application of two sets of criteria related to: (a) methodological quality, and (b) measurement of the predictive factor. Based on the quality and the consistency of the findings, a rating system was used to assess the level of evidence for each predictive factor.


RESULTS
Nineteen publications (17 cohorts) were identified, of which 13 met the general methodological quality criteria. Results provided strong evidence that physical job demands, low functional capacity, old age, and low education predict work disability in RA. Remarkably, biomedical variables did not consistently predict work disability. Moreover, owing to the lack of high quality studies no evidence was found for personal factors such as coping style, and work environmental factors such as work autonomy, support, work adjustments that are presumed crucial in the work disablement process.


CONCLUSIONS
The results indicate that work disability in RA is a biopsychosocially determined misfit between individual capability and work demands.
Coronel Institute for Occupational and Environmental Health, Academic Medical Centre, Research Institute Amsterdam Centre for Health and Health Care Research, 1105 AZ Amsterdam, The Netherlands. e.m.decroon@amc.uva.nl
E M
EM
de Croon
J K
JK
Sluiter
T F
TF
Nijssen
B A C
BA
Dijkmans
G J
GJ
Lankhorst
M H W
MH
Frings-Dresen
D000223:Adaptation, Psychological; D000367:Age Factors; D001172:Arthritis, Rheumatoid / Q000503:physiopathology* / Q000523:psychology; D004185:Disability Evaluation; D004522:Educational Status; D006801:Humans; D007596:Joints / Q000503:physiopathology*; D009042:Motivation; D011237:Predictive Value of Tests; D014937:Work; D016526:Workload