Table 3

Results from a multivariate logistic regression model using the variables selected and defined based on the factor analysis.

Variable	Comparison	B	p Value	OR (95% CI)	Weight^*
Swollen MCP	Present vs absent	0.38	0.003	1.5 (1.1 to 1.9)	1.5
Swollen PIP	Present vs absent	0.41	0.001	1.5 (1.2 to 1.9)	1.5
Swollen wrist	Present vs absent	0.48	<0.001	1.6 (1.3 to 2.0)	1.5
Hand tenderness	Present vs absent	0.59	<0.001	1.8 (1.3 to 2.4)	2
Acute phase^†	Moderate vs normal	0.22	0.172	1.2 (0.9 to 1.7)	1
Acute phase^†	High vs normal	0.52	0.001	1.7 (1.2 to 2.3)	2
Serology^†	Moderate vs normal	0.89	<0.001	2.2 (1.8 to 3.3)	2
Serology^†	High vs normal	1.35	<0.001	3.9 (3.0 to 5.0)	4

↵* Variable weight approximated based on the OR of the variable in the model.
↵† Definition of ‘normal’ is based on local standards and definitions of ‘moderate’ and ‘high’ are based on distributions of values below or above the median of the non-normal values.
MCP, metacarpophalangeal; PIP, proximal interphalangeal.