Table 2

 Results of the best evidence synthesis

FactorStudiesAssociationEvidence (direction)
Note. Studies between brackets were not taken into account in the evidence synthesis.
Positive association, the presence of the factor or a higher level of the factor increases the chance of future work disability; negative association, the presence of the factor or a higher level of the factor decreases the chance of future work disability; RF+, rheumatoid factor positivity; ESR, erythrocyte sedimentation rate; BMI, body mass index.
The evidence synthesis is based on the univariate associations when available or the multivariate associations when univariate associations are unavailable.
1. Factors that mirror RA directly
RF+Sokka,2 Barrett,3 Wolfe,1 Mau30No,2,3 positive1,30Inconsistent
[Callahan,13 Young31No13,31]
Disease durationWolfe,1 Reisine,27 Callahan,13 De Roos,33 Chorus32No,1,27 positive13,32,33Inconsistent
2.Impaired body function or body structure
Variables of disease activityInconsistent
    ESRSokka,2 Borg,28 Wolfe,1 Young31No,2,28 positive1,31
[Callahan,13 Doeglas4No,13 positive4]
    Tender jointsWolfe1Positive1
[Callahan,13 Young31Positive13,31]
    Inflamed, swollen or flared jointsSokka,2 Reisine,27 Borg,28 Mau30No,2,27,28 positive30
[Callahan,13 Fex,34 Young31No,13 positive31,34]
Patient’s or physician’s global assessmentBorg,28 Wolfe1 [Sokka,2 Callahan13No,28 positive1 Positive2,13]
Pain and emotional functions
    PainReisine,27 Borg,28 Wolfe1No,27,28 positive1Inconsistent
[Fex,34 Sokka,2 Callahan,13 Young,31 De Roos33No,34 positive2,13,31,33]
    Emotional functionsFex,34 Borg,28 Wolfe1No,34 positive1,28Weak (positive)
[De Roos33Positive33]
Structural damageSokka,2 Reisine,27 Young,31 Mau30No,2,27 positive30,31Inconsistent
[Fex,34 Callahan13No,34 positive13]
3. Activity limitations
(Modified) HAQ-disabilityWolfe,1 Sokka,2 Barrett,3 Fex,34 Young,31 Borg28Positive1–3,28,31,34Strong (positive)
[Callahan,13 Doeglas,4 De Roos,33 Chorus32Positive4,13,32,33]
Grip strengthWolfe1Negative1No
Morning stiffness (min)[Callahan13No13]
4. (Work) environment
Work autonomyReisine27No27No
Job transitionSokka2Negative2No
Job training after diagnosis[Chorus32Negative32]No
Workplace accessibility/mobility[Chorus32Negative32]No
Work adjustments[Chorus32Negative32]No
Support at work[Chorus32Negative32]No
Complexity of working with things[Wolfe1No1]No
Complexity of working with data[Wolfe1Negative1]No
Supervising othersReisine,27 Chorus,32 Wolfe1No,27,32 negative1Inconsistent
Physical job demands
    Self reported[Reisine,27 Fex,34 Mau30Positive27,30,34]Strong (positive)
    OccupationBarrett,3 Wolfe,1 Sokka,2 Callahan,13 Reisine27 Holte,29 Young,31 De Roos,33 Chorus,32 Borg28No,3 positive1,2,13,27–29,31–33
Self employmentReisine27Negative27No
Working hoursReisine,27 Holte29Negative27,29Weak (negative)
Company sizeChorus32No32No
Temporary job positionChorus32No32No
Career opportunities[Chorus32Negative32]No
Job satisfaction[Fex,34 Reisine27No27,34]No
Financial situationReisine,27 Borg,28 Holte29No,27,28 negative29Inconsistent
Impact of RA on family roleReisine27No27No
Social supportReisine27No27No
Car/stair deprivation[Young31Positive31]No
5. Person
AgeBarrett,3 Sokka,2 Callahan,13 Reisine,27 Doeglas4 Fex,34 Young,31 Mau,30 De Roos,33 Chorus,32 Borg28No,3 positive2,4,13,27,28,30–34Strong (positive)
SexSokka,2 Barrett,3 Callahan,13 Reisine,27 Fex,34 Borg,28 Wolfe,1 Young,31 De Roos,33 Chorus32No,2,3,13,27,28,34 yes1,31–33Inconsistent
Marital statusCallahan,13 Reisine,27 Holte,29 Fex,34 De Roos,33 Borg,28 Sokka2No,13,27–29,33,34 yes2Strong (no)
EducationBarrett,3 Holte,29 Borg,28 Reisine,27 Wolfe,1 Sokka2 Callahan,13 Doeglas,4 Fex,34 De Roos33 Chorus32No,3,28,29 negative1,2,4,13,27,32–34Strong (negative)
RaceCallahan,13 Wolfe,1 De Roos33No,13 yes1,33Weak (non-white → work disability)
Desire for paid work[Reisine27No27No]
Comorbid conditions[Callahan13Positive13No]
Coping[Callahan,13 Chorus32Positive13,32No]