Table 2.

Associations between high (SSS-8 ≥ 12) or very high somatising tendency (SSS-8 ≥ 16) and disability due to knee pain from multiple logistic regression models (n = 14,695)

	SSS8 ≥ 12			SSS8 ≥ 16
	OR [95% CI]a	p-value	Type 3 p-value	OR [95% CI]a	p-value	Type 3 p-value
Disability due to pain			< 0.001			< 0.001
Knee pain without difficulty in ADL	1			1
Knee pain with difficulty but without sick leave	2.36 [2.10, 2.66]	< 0.001		2.80 [2.42, 3.23]	< 0.001
Knee pain with sick leave	3.23 [2.66, 3.92]	< 0.001		4.51 [3.64, 5.58]	< 0.001
Chronic knee pain yes vs. no	1.28 [1.16, 1.41]	< 0.001		1.12 [0.98, 1.28]	0.103

SSS-8 Somatic Symptom Scale-8, OR odds ratio, CI confidence interval, ADL activities of daily living

^aAdjusted for age, sex, body mass index, depressive symptoms (Patient Health Questionnaire-2 (PHQ-2)), education, regular exercise, osteoarthritis, rheumatoid arthritis, and fibromyalgia