Table 3.

Multivariable logistic regression analyses for the association of AUSCAN for hand OA physical function subscale score with clinical hand OA^*

Model	Clinical hand osteoarthritis	βa	Standard Error	P	Δβ%b	OR	95% CI
1	Plus sex, age, country of origin, education level (less than secondary)	2.7806	0.1503	<0.0001		16.129	12.015-21.652
2	Plus sex, age, country of origin, education level (less than secondary), and comorbidity (≥ 3 diseases)	2.7642	0.1522	<0.0001	0.6	15.866	11.773-21.382
3	Plus sex, age, country of origin, education level (less than secondary), comorbidity (≥ 3 diseases), and AUSCAN for hand OA pain subscale scorec	0.9977	0.2042	<0.0001	177.1	2.712	1.817-4.047
4	Plus sex, age, country of origin, education level (less than secondary), comorbidity (≥ 3 diseases), AUSCAN for hand OA pain subscale scorec, and interaction of clinical hand OA with AUSCAN for hand OA pain subscale score	1.6275	0.2775	<0.0001			#

^*The outcome being measured was the likelihood of having more impairment (an AUStralian/CANadian Osteoarthritis Hand Index [AUSCAN] for hand osteoarthritis [OA] physical function score in the highest quartile) versus not having more impairment (a score in the lower quartiles).

^aEstimated coefficients.

^bAmount of adjustment = 100 x (β previous Model – β Model) / β Model.

^cPossible AUSCAN for hand OA pain subscale scores range from 0 to 100, with 0 indicating no pain.

Controlled direct effect: P <0.0001, odds ratio (OR) 5.091 (95% confidence interval [95% CI] 2.955-8.773); natural direct effect: P = 0.5622, OR 0.763 (95% CI 0.305-1.907); natural indirect effect: P <0.0001, OR 5.563 (95% CI 3.222-9.604); total effect: P <0.0001, OR 14.463 (95% CI 8.300-25.200)

^#Estimated ORs for clinical hand OA as a function of AUSCAN for hand OA pain subscale scores of 0, 5, 15, and 25 were 5.091 (95% CI 2.955-8.773), 4.016 (95% CI 2.533-6.366), 2.498 (95% CI 1.657-3.767), 1.554 (95% CI 0.906-2.665), respectively.