Table 6.

Risks of surgically treated CTS associated with different numbers/combinations of biomechanical risk factors (use of vibratory tools; forceful hand/wrist movements; frequent repetitive hand/wrist movements; uncomfortable hand postures; frequent pinching actions; skin compression) among non-retired subjects

			Univariate	Multivariate*
	Cases (n = 191)	Controls (n = 286)	OR (95% CI)	OR (95% CI)
No risk factor†	82	215	1.0	1.0
1 risk factor	48	42	3.0 (1.8-4.9)	2.8 (1.6-4.8)
Either force or frequency	41	33	3.3 (1.9-5.6)	3.2 (1.7-5.8)
Any other factor	7	9	2.0 (0.7-5.7)	1.4 (0.5-4.6)
2 risk factors	23	9	6.7 (2.9-15.6)	7.1 (2.9-17.4)
Any 2 factors from: force, frequency and posture	15	4	9.8 (3.0-31.9)	10.3 (3.0-35.1)
Other combinations (of 2 risk factors)	8	5	4.2 (1.3-13.4)	4.0 (1.1-14.8)
3-4 risk factors	31	17	4.8 (2.4-9.3)	4.5 (2.1-9.3)
At least 3 factors from: force, frequency, posture and compression	16	3	14.0 (3.7-52.2)	14.9 (3.9-57.6)
Other combinations (of 3 or 4 risk factors)	15	14	2.8 (1.3-6.1)	2.2 (0.9-5.5)
5-6 risk factors	7	3	6.1 (1.5-24.8)	5.0 (1.1-22.6)

*The results derive from two separate multivariate unconditional logistic regression models (evaluating numbers/combinations of risk factors). Each model was adjusted for the individual factors entered in the multivariate model reported in Table 1 (ie BMI, height, alcohol, family history of CTS, rheumatoid arthritis, trigger finger and diabetes mellitus), as well as age, gender and center.

†Reference category.