Table 2.

Linear regression analysis showing a significant interaction between ethnicity, cortisol concentrations obtained prior to the CPT, and pain intensity ratings during the CPT in persons with knee OA (N = 91).

Variable	B (SE)	β	95% CI	P value
Age	−0.06 (0.37)	−0.02	−0.78, 0.67	0.88
Sex	−7.65 (6.12)	−0.13	−19.86, 4.55	0.22
Education	−6.75 (5.59)	−0.12	−17.88, 4.39	0.23
Smoking Status	6.19 (7.17)	0.09	−8.09, 20.47	0.39
Corticosteroid
Medication Use	7.36 (7.60)	0.09	−7.78, 22.50	0.34
BMI	0.01 (0.35)	0.00	−0.69, 0.71	0.97
OA Pain Intensity	0.21 (0.14)	0.15	−0.06, 0.49	0.13
CPTo	−13.86 (3.16)	−0.40	−20.17, −7.56	< 0.001
Ethnicity	−2.83 (5.98)	−0.05	−14.73, 9.08	0.64
Cortisol	−0.45 (0.97)	−0.05	−2.38, 1.48	0.65
Ethnicity*Cortisol	−3.52 (1.51)	−0.26	−6.52, −0.51	0.02

Note: CPT = cold-pressor task; OA = knee osteoarthritis; Sex: 0 = female; 1 = male; Education: 0 = high school or less, 1 = some college or more; Smoking Status: 0 = not a current smoker, 1 = current smoker; Corticosteroid Medication Use: 0 = no corticosteroid medication use, 1 = current use of corticosteroid medications; BMI = body mass index; CPTo = cold pain tolerance