Table 4.

Logistic regression model of clinically important weight gain (≥ 5% body weight) and TKA case/REP control status

	Unadjusted Analysis		Adjusted Analysis
Variable	Odds Ratio (95% CI)	P-value	Odds Ratio (95% CI)	P-value
Subject Status
TKA (follow-up arthroplasty)	2.3 (1.6, 3.2)	<0.001	2.1 (1.4, 3.1)	<0.001
TKA (no follow-up arthroplasty)	1.7 (1.3, 2.3)	<0.001	1.6 (1.2, 2.2)	0.003
REP Control	1.0 (reference)		1.0 (reference)
BMI
>= 25.0 – < 30.0	0.7 (0.5, 1.0)	0.054	0.7 (0.5, 1.0)	0.09
>= 30.0 – < 35.0	0.9 (0.7, 1.3)	0.58	0.8 (0.6, 1.2)	0.24
>= 35	0.8 (0.6, 1.1)	0.20	0.6 (0.4, 0.9)	0.02
<25	1.0 (reference)		1.0 (reference)
Age
<60	2.1 (1.5, 2.8)	<0.001	2.7 (1.8, 3.9)	<0.001
60 to 69	1.5 (1.1, 2.0)	0.01	1.7 (1.2, 2.3)	0.004
70 to 75	1.1 (0.9, 1.4)	0.55	1.2 (0.8, 1.8)	0.36
>75	1.0 (reference)		1.0 (reference)
Gender
Male	1.1 (0.9, 1.4)	0.41	1.2 (0.9, 1.5)	0.19
Female	1.0 (reference)		1.0 (reference)
Education
< HS diploma	1.0 (0.7, 1.5)	0.92	1.2 (0.8, 1.7)	0.50
HS or some college	1.0 (0.7, 1.2)	0.70	1.0 (0.7, 1.3)	0.86
College degree or >	1.0 (reference)		1.0 (reference)
Deyo-Charlson Index
0	0.9 (0.7, 1.1)	0.19	0.8 (0.6, 1.0)	0.08
1	1.0 (0.8, 1.4)	0.89	0.9 (0.6, 1.2)	0.36
>1	1.0 (reference)		1.0 (reference)
Pre-surgical 5-yr max wt loss, per 1 Kg*	1.10 (1.07, 1.13)	<0.001	1.10 (1.07, 1.13)	<0.001
Pre-surgical 5-yr max wt gain, per 1 Kg#	0.99 (0.97, 1.01)	0.92	0.99 (0.97, 1.01)	0.44

TKA = total knee arthroplasty, REP = Rochester Epidemiology Project

^*Maximum weight loss (in Kgs), relative to baseline, during the 5-years prior to the baseline knee arthroplasty.

^#Maximum weight gain (in Kgs), relative to baseline, during the 5-years prior to the baseline knee arthroplasty.