Table III.

Risk factors for increased use of opioids following UKA

UKA (mths)	Female vs male	Age < 50 yrs vs ≥ 50 yrs	Anxiety/depression vs none	Low back pain vs none	Myalgia vs none	Drug dependence vs none	Smoker vs none
1	1.02 (0.9 to 1.1)*	1.2 (1.2 to 1.3)	1.1 (1.1 to 1.2)	1.1 (1.01 to 1.1)	1.01 (1.01 to 1.11)	1.2 (1.1 to 1.3)	1.02 (0.9 to 1.1)*
2	1.3 (1.1 to 1.4)	1.8 (1.5 to 2.2)	1.6 (1.4 to 1.9)	1.4 (1.3 to 1.6)	1.4 (1.2 to 1.6)	2.2 (1.9 to 2.7)	1.6 (1.4 to 1.9)
3	1.2 (1.01 to 1.3)	2.2 (1.7 to 2.8)	1.9 (1.5 to 2.3)	1.8 (1.6 to 2.1)	1.5 (1.2 to 1.7)	3.0 (2.4 to 3.8)	1.9 (1.6 to 2.3)
4	1.1 (0.9 to 1.3)*	2.0 (1.5 to 2.7)	2.2 (1.8 to 2.7)	1.9 (1.6 to 2.2)	1.7 (1.5 to 2.1)	3.5 (2.8 to 4.5)	2.0 (1.7 to 2.5)
5	1.1 (0.9 to 1.3)*	2.0 (1.5 to 2.7)	2.3 (1.9 to 2.9)	2.0 (1.7 to 2.4)	1.9 (1.6 to 2.3)	3.7 (2.9 to 4.9)	2.1 (1.7 to 2.6)
6	1.3 (1.1 to 1.5)	2.0 (1.4 to 2.7)	2.4 (1.9 to 3.0)	2.2 (1.9 to 2.6)	2.2 (1.8 to 2.6)	3.6 (2.7 to 4.7)	2.3 (1.8 to 2.8)
7	1.2 (1.02 to 1.4)	2.1 (1.5 to 2.9)	2.3 (1.8 to 2.9)	2.4 (2.0 to 2.8)	2.1 (1.8 to 2.6)	4.8 (3.8 to 6.1)	2.4 (2.0 to 3.0)
8	1.2 (1.03 to 1.4)	1.7 (1.2 to 2.4)	2.3 (1.8 to 2.9)	2.4 (2.0 to 2.8)	1.9 (1.6 to 2.3)	4.4 (3.4 to 5.6)	2.5 (2.0 to 3.0)
9	1.2 (1.03 to 1.5)	1.6 (1.1 to 2.3)	2.3 (1.8 to 2.9)	2.4 (2.1 to 2.9)	2.0 (1.7 to 2.4)	3.8 (2.9 to 5.0)	2.0 (1.6 to 2.5)
10	1.2 (1.04 to 1.5)	1.7 (1.2 to 2.4)	2.6 (2.1 to 3.3)	2.4 (2.0 to 2.8)	1.9 (1.6 to 2.3)	4.5 (3.5 to 5.8)	2.5 (2.0 to 3.1)
11	1.1 (0.9 to 1.3)*	2.0 (1.4 to 2.8)	2.5 (2.1 to 3.2)	2.3 (1.9 to 2.7)	2.1 (1.8 to 2.5)	3.7 (2.9 to 4.9)	2.3 (1.9 to 2.9)
12	1.2 (0.9 to 1.4)*	1.4 (0.9 to 2.2)*	2.3 (1.8 to 2.9)	2.5 (2.1 to 2.9)	2.3 (2.0 to 2.8)	4.0 (3.0 to 5.2)	2.3 (1.8 to 2.8)

Data presented as risk ratios (95% confidence interval) *95% confidence interval crosses one, thus risk ratio is not significant UKA, unicompartmental knee arthroplasty