Appendix B.

Regression Models for Total Hip Arthroplasty.

Covariates	HOOS		PROMIS-PH		NPRS
	β	P	β	P	β	P
Surgical approach (ref = posterior)	0		0		0
Transgluteal	1.7	.040a	0.9	.051	−0.1	.316
Anterior	0.3	.661	0.2	.636	−0.1	.405
Follow-up (ref = baseline)	0		0		0
1 mo	28.3	.000c	7.7	.000c	−4.1	.000c
3 mo	35	.000c	10.1	.000c	−4.4	.000c
6 mo	37.8	.000c	10.9	.000c	−4.5	.000c
Approach interaction (ref = posterior)	0		0		0
Transgluteal, 1 mo	−2.2	.01a	−1.3	.002b	0.2	.125
3 mo	−1.9	.048a	−0.7	.081	0.1	.455
6 mo	−1.8	.063	−1.0	.026a	0.1	.514
Anterior, 1 mo	−0.8	.331	−0.1	.679	0.2	.073
3 mo	−0.8	.346	0.1	.679	0.1	.397
6 mo	−0.5	.508	0.2	.558	0	.71
Year	0.1	.000c	0	.001b	−0.0	.002b
Sex (ref = male)	0		0		0
female	−1.5	.000c	−1.4	.000c	0.2	.000c
Body mass index	−0.1	.033a	−0.2	.000c	0	.102
Race (ref = white)	0		0		0
Black	−3.7	.000c	−1.2	.001c	0.7	.000c
Other or multiple	−0.2	.887	0.2	.8	0	.935
Hispanic (ref = No)	0		0		0
Yes	−5.9	.000c	−1.6	.057	0.7	.001b
Education (ref = less than college)	0		0		0
College or higher	2.1	.000c	0.8	.000c	−0.3	.000c
Work status (ref = working)	0		0		0
Unemployed	−0.2	.901	−1.8	.043a	0.2	.35
Sick or disabled	−5.9	.000c	−5.0	.000c	0.9	.000c
Student, homemaker, retired	−0.8	.138	−0.9	.002b	0	.633
Alcohol use (ref = never)	0		0		0
Monthly or less	0.9	.139	0.5	.082	−0.2	.010b
2–4 Times a month	0.7	.271	1	.006b	−0.1	.174
2–3 Times a week	1.2	.078	1.7	.000c	−0.2	.009b
≥4 Times a week	2	.004b	1.8	.000c	−0.4	.000c
Smoking status (ref = never)	0		0		0
Current	−5.7	.000c	−2.9	.000c	0.7	.000c
Former	−2.3	.000c	−1.4	.000c	0.2	.000c
Comorbidity (ref = no)	0		0		0
COPD	−2.3	.028a	−2.0	.000c	0.4	.007b
Paralysis	−1.2	.663	0.9	.527	−0.7	.049a
Heart attack	−0.3	.805	−1.4	.020a	0	.945
Carotid artery disease	−3.5	.097	−1.6	.174	0.1	.703
Stroke	−1.9	.177	−2.0	.008b	0.3	.145
Rheumatoid arthritis	−2.5	.001c	−2.4	.000c	0.4	.000c
Diabetes	−0.7	.282	−1.0	.004b	0.1	.211
Cancer	0.8	.305	−0.2	.585	−0.2	.018a
Liver disease	−1.2	.457	−0.6	.459	0.1	.711
Peripheral vascular disease	−0.2	.927	0.3	.713	−0.2	.361
Kidney disease	−2.0	.116	−2.3	.001b	0.3	.094
Ulcer disease	−4.3	.005b	−1.8	.024a	0.8	.000c
HIV or AIDS	3.7	.042a	1.8	.074	−0.1	.7
Constant	46.4	.000c	45.6	.000c	6.1	.000c
Variance parameters
Center (se)	1.1	−.66	0.4	−.23	0.06	−.023
Participant (se)	67.8	−3.26	24.9	−.91	1.03	−.06
Residual (se)	137	−2.54	26.6	−.47	2.91	−.05

Based on multivariable mixed effects regression with robust standard errors clustering for observations within individual patients and patients nested within hospitals. HOOS Jr, the brief Hip disability and Osteoarthritis Outcomes Score; PROMIS-PH, Patient-Reported Outcomes Measurement Information System Physical Health Summary; NPRS, Numeric Pain Rating Scale; ref, reference; COPD, chronic obstructive pulmonary disease; HIV, human immunodeficiency virus; AIDS, acquired immune deficiency syndrome.

^aP < .05.

^b<0.01.

^c<0.001.