Work Ability and Employment in Rheumatoid Arthritis: A Cross-Sectional Study on the Role of Muscle Strength and Lower Extremity Function

Table 3

Univariate analysis of associations between sociodemographic, clinical characteristics, and workability (workability index single item, WAS).

Workability (WAS)
Variable		p-value
Age - years	- 0.10	<0.001
Sex: male	Reference
female	0.94	0.108
Marital status: in a relationship	Reference
living alone	-0.19	0.757
Education: compulsory	Reference
secondary	1.26	0.083
higher	2.94	0.005
Disease duration - months	-0.01	0.003
Disease activity (CDAI) - points	-0.10	0.003
Pain (VAS) - points	-0.67	<0.001
Functional disability (HAQ) - points	-2.63	<0.001
CRP - mg/dl	-0.02	0.275
IL-6 - pg/dl	-0.03	0.291
TNF-alpha - µg/dl	-0.14	0.217
RA therapy: sDMARDs	1.09	0.111
bDMARDs	- 1.52	0.787
Corticosteroids	0.32	0.660
NSAIDs/Pain killers	- 1.02	0.185
Comedication	-1.81	0.001
Comorbidity	-1.50	0.009
Muscle strength: hand grip - kg	0.05	0.012
Knee extensor - kg	0.06	<0.001
Lower Extremity function (SPPB) - points	0.81	<0.001

=Beta coefficient, CDAI=clinical disease activity index, VAS=visual analogue scale, CRP=C-reactive protein, IL-6=interleukin-6, TNF-alpha=tumor necrosis factor-alpha, s/b DMARD=synthetic/biological disease-modifying antirheumatic drug, RA=rheumatoid arthritis, and SPPB=short physical performance battery.