Table 1.

Relative risk for prolonged length of stay, extremely prolonged length of stay, and index hospitalization mortality stratified by comorbidity subgroup among primary and revision TJA patients in the United States, 2006–2014.

	Prolonged LOS (≥5 days)			Extremely Prolonged LOS (≥10 days)			Index Hospitalization Mortality
	RR		P Value	RR		P Value	RR		P Value
Primary Hip
Minor	1.00	–	–	1.00	–	–	1.00	–	–
Moderate	1.98	(1.96–2.00)	<0.0001	1.36	(1.34–1.39)	<0.0001	8.79	(6.88–11.23)	<0.0001
Major	3.78	(3.74–3.83)	<0.0001	3.09	(3.01–3.19)	<0.0001	93.13	(74.65–116.19)	<0.0001
Extreme	5.40	(5.33–5.48)	<0.0001	7.25	(7.02–7.49)	<0.0001	780.85	(634.05–961.63)	<0.0001
Primary Knee
Minor	1.00	–	–	1.00	–	–j	1.00	–	–
Moderate	1.72	(1.71–1.74)	<0.0001	1.10	(1.08–1.12)	<0.0001	3.86	(3.15–4.75)	<0.0001
Major	3.67	(3.63–3.72)	<0.0001	2.19	(2.12–2.26)	<0.0001	37.78	(31.38–45.49)	<0.0001
Extreme	5.62	(5.55–5.70)	<0.0001	6.62	(6.42–6.83)	<0.0001	494.87	(425.80–575.15)	<0.0001
Revision Hip
Minor	1.00	–	–	1.00	–	–	1.00	–	–
Moderate	1.79	(1.76–1.82)	<0.0001	1.78	(1.72–1.84)	<0.0001	9.26	(6.02–14.25)	<0.0001
Major	2.63	(2.59–2.67)	<0.0001	3.73	(3.60–3.87)	<0.0001	62.01	(41.43–92.79)	<0.0001
Extreme	3.01	(2.96–3.06)	<0.0001	6.36	(6.12–6.61)	<0.0001	443.85	(301.26–653.92)	<0.0001
Revision Knee
Minor	1.00	–	–	1.00	–	–	1.00	–	–
Moderate	1.94	(1.90–1.98)	<0.0001	1.70	(1.63–1.78)	<0.0001	6.44	(3.52–11.75)	<0.0001
Major	3.36	(3.29–3.43)	<0.0001	4.05	(3.86–4.25)	<0.0001	46.54	(26.82–80.76)	<0.0001
Extreme	4.32	(4.23–4.40)	<0.0001	8.61	(8.21–9.02)	<0.0001	517.76	(314.67–851.92)	<0.0001

The values are given as relative risk with 95% CI in parentheses.