Table 5.

Logistic regression model of clinically important weight gain (≥ 5% body weight) among persons with knee arthroplasty

Variable	Unadjusted Analysis		Adjusted Analysis
	Odds Ratio (95% CI)	P-value	Odds Ratio (95% CI)	P-value
Subject Status
TKA Case (follow-up arthroplasty)	1.3 (1.0, 1.7)	0.02	1.3 (0.9, 1.7)	0.13
TKA Case (no follow-up arthroplasty)	1.0 (reference)		1.0 (reference)
BMI
>= 25.0 – < 30.0	0.7 (0.5, 1.0)	0.08	0.8 (0.5 (1.2)	0.25
>= 30.0 – < 35.0	0.8 (0.6, 1.2)	0.35	0.8 (0.5, 1.3)	0.36
>= 35	0.8 (0.5, 1.1)	0.13	0.8 (0.5, 1.2)	0.23
<25	1.0 (reference)		1.0 (reference)
Age
<60	2.2 (1.6, 3.1)	<0.001	3.0 (1.9, 4.8)	<0.001
60 to 69	1.5 (1.1, 2.0)	0.02	1.6 (1.1, 2.4)	0.02
70 to 75	1.2 (0.8, 1.7)	0.34	1.4 (0.9, 2.2)	0.13
>75	1.0 (reference)		1.0 (reference)
Gender
Male	1.1 (0.8, 1.4)	0.65	1.2 (0.9, 1.5)	0.34
Female	1.0 (reference)		1.0 (reference)
Diagnosis
Osteoarthritis	0.8 (0.5, 1.1)	0.13	1.0 (0.6, 1.6)	0.99
Other	1.0 (reference)		1.0 (reference)
Education
< HS diploma	1.2 (0.8, 1.7)	0.40	1.3 (0.8, 2.2)	0.22
HS or some college	1.1 (0.8, 1.4)	0.63	1.0 (0.7, 1.4)	0.97
College degree or >	1.0 (reference)		1.0 (reference)
ASA score
III or IV	0.9 (0.7, 1.2)	0.44	0.9 (0.7, 1.2)	0.50
I or II	1.0 (reference)		1.0 (reference)
Charlson Index
0	0.9 (0.7, 1.2)	0.41	0.8 (0.6, 1.1)	0.24
1	1.1 (0.8, 1.4)	0.77	0.8 (0.6, 1.2)	0.39
>1	1.0 (reference)		1.0 (reference)
Pre-surgical 5-yr max wt loss, per 1 Kg*	1.09 (1.06, 1.12)	<0.001	1.1 (1.07, 1.13)	<0.001
Pre-surgical 5-yr max wt gain, per 1 Kg#	1.0 (0.98, 1.02)	0.84	0.98 (0.96, 1.01)	0.19

TKA = total knee arthroplasty

^*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.