Table 4.

Multivariate logistic model for whether separate SES variables individually predict facility discharge (37.9%) among primary TKAs (n=2,196)^a

	With SES Variables			No SES Variables
Variable	OR	95% CI	P-Value	OR	95% CI	P-Value
Race (ref = Non-Hispanic White)
Other	4.43	2.03–9.64	<0.001	--	--	--
Living Alone (ref = No)
Yes	2.62	1.62–4.23	<0.001	--	--	--
Missing	0.83	0.44–1.58	0.577	--	--	--
Education (ref = Postgrad)
College	0.92	0.50–1.67	0.778	--	--	--
Some College	1.19	0.67–2.13	0.555	--	--	--
High School or Less	1.01	0.56–1.82	0.965	--	--	--
Missing	1.08	0.41–2.81	0.878	--	--	--
Employment (ref = Working/Student)
Retired, Not for Health	1.25	0.75–2.06	0.390	--	--	--
Not Working	1.78	1.05–3.01	0.031	--	--	--
Missing	1.12	0.43–2.91	0.823	--	--	--
Household Annual Income (ref = $75,000+)
$50–75,000	1.06	0.50–2.28	0.875	--	--	--
$35–50,000	0.76	0.34–1.68	0.498	--	--	--
<$35,000	0.94	0.46–1.92	0.864	--	--	--
Refused to Answer	0.58	0.29–1.15	0.117	--	--	--
Missing	1.22	0.58–2.54	0.596	--	--	--
Surgeon (ref = Surgeon 1)
Surgeon 2	1.69	1.13–2.53	0.011	1.66	1.12–2.46	0.012
Surgeon 3	0.48	0.15–1.55	0.220	0.51	0.16–1.57	0.239
Surgeon 4	0.93	0.19–4.48	0.931	0.82	0.17–3.99	0.809
Surgeon 5	1.52	0.69–3.31	0.295	1.72	0.79–3.76	0.176
Surgeon 6	0.83	0.56–1.24	0.367	0.83	0.56–1.25	0.375
Surgeon 7	1.06	0.74–1.51	0.752	1.10	0.78–1.55	0.598
Surgeon 8	1.29	0.76–2.20	0.350	1.31	0.77–2.23	0.321
Surgeon 9	0.45	0.19–1.08	0.073	0.47	0.19–1.15	0.099
Surgeon 10	1.10	0.71–1.69	0.682	1.09	0.71–1.66	0.706
Age Group (ref = <55)
55–59	1.36	0.83–2.23	0.224	1.30	0.80–2.13	0.289
60–64	2.41	1.50–3.88	<0.001	2.33	1.45–3.74	<0.001
65–69	4.42	2.75–7.10	<0.001	4.20	2.63–6.71	<0.001
70–74	7.49	4.56–12.31	<0.001	7.14	4.38–11.65	<0.001
75–79	16.65	9.55–29.03	<0.001	15.66	9.12–26.91	<0.001
80+	20.38	11.22–37.02	<0.001	18.75	10.44–33.67	<0.001
Sex (ref = Male)
Female	2.00	1.56–2.57	<0.001	2.07	1.62–2.66	<0.001
Preoperative Alcohol Use (ref = No)
Yes	0.60	0.47–0.78	<0.001	0.60	0.47–0.76	<0.001
Preoperative Tobacco Use (ref = Never)
Quit	1.03	0.80–1.33	0.792	1.06	0.83–1.36	0.620
Yes	1.22	0.71–2.11	0.477	1.29	0.76–2.19	0.353
Charlson Score (ref = 0)
1	1.23	0.92–1.66	0.162	1.23	0.92–1.64	0.163
2+	1.55	1.14–2.10	0.005	1.53	1.13–2.06	0.005
VR-12 PCS Preoperative (ref = 50+)
40–49.99	2.38	1.33–4.23	0.003	2.53	1.44–4.44	0.001
30–39.99	2.53	1.47–4.37	0.001	2.74	1.60–4.68	<0.001
20–29.99	3.43	2.02–5.82	<0.001	3.69	2.19–6.22	<0.001
<20	4.91	2.66–9.05	<0.001	5.25	2.89–9.52	<0.001
VR-12 MCS Preoperative (ref = 60+)
50–59.99	1.64	1.20–2.24	0.002	1.64	1.21–2.21	0.001
40–49.99	2.53	1.75–3.66	<0.001	2.59	1.81–3.73	<0.001
30–39.99	2.91	1.89–4.47	<0.001	2.94	1.92–4.49	<0.001
<30	2.29	1.32–3.99	0.003	2.26	1.32–3.85	0.003
Year (ref = 2011)
2012	1.38	0.89–2.14	0.145	1.43	0.94–2.19	0.098
2013	1.76	1.13–2.75	0.013	1.84	1.21–2.81	0.005
2014	1.40	0.86–2.27	0.171	1.48	0.93–2.34	0.098
2015	1.16	0.68–1.97	0.588	1.13	0.68–1.89	0.640
2016	1.70	0.74–3.93	0.213	1.67	0.75–3.73	0.208
Bilateral TKA (ref = No)
Yes	21.43	15.72–29.23	<0.001	18.99	14.04–25.69	<0.001
BMI Preoperative (ref = Normal, <25)
Overweight, 25–29.99	0.92	0.62–1.36	0.661	0.93	0.63–1.36	0.694
Obese, 30–34.99	1.27	0.85–1.91	0.245	1.30	0.88–1.93	0.193
Severe Obese, 35–39.99	1.27	0.82–1.98	0.290	1.27	0.82–1.96	0.276
Morbid Obese, 40+	3.89	2.44–6.20	<0.001	3.81	2.40–6.03	<0.001
10-fold cross-validation AUC
	0.87	0.85 – 0.88		0.86	0.84 – 0.87

Clustered on 2,059 patients and using robust standard errors to account for observational data

^a2 in-hospital deaths occurred and were not discharged.