Appendix 1.

Summary of the multiple regression analyses with the PROMIS-29 T-scores as dependent variables and demographic and clinical characteristics as independent variables

Dependent variable	Independent variable	Unstandardized coefficient (B)	SE B	Standardized coefficient (β)	p	R2	Adjusted R2
Physical function	(Intercept)	45.72	1.25	-	<.0001	0.26	0.26
	Amputation transtibiala	3.29	0.47	0.19	<.0001
	Traumatic etiologyb	3.34	0.56	0.20	<.0001
	Female gender	−2.11	0.48	−0.12	<.0001
	Non-Hispanic blackc	−1.52	0.78	−0.05	0.05
	Hispanicc	−2.79	0.92	−0.08	0.00
	Other ethnicityc	−3.10	1.11	−0.07	0.01
	Years since amputation	0.16	0.02	0.27	<.0001
	Age	−0.16	0.02	−0.25	<.0001
Anxiety	(Intercept)	53.16	1.60	-	<.0001	0.06	0.06
	Amputation transtibiala	−0.90	0.60	−0.05	0.13
	Traumatic etiologyb	−0.87	0.72	−0.05	0.22
	Female gender	2.33	0.62	0.11	0.00
	Non-Hispanic blackc	1.52	0.99	0.05	0.13
	Hispanicc	1.19	1.18	0.03	0.31
	Other ethnicityc	2.57	1.40	0.05	0.07
	Years since amputation	−0.11	0.02	−0.16	<.0001
	Age	−0.04	0.02	−0.06	0.07
Depression	(Intercept)	53.90	1.57	-	<.0001	0.06	0.06
	Amputation transtibiala	−0.67	0.59	−0.03	0.26
	Traumatic etiologyb	−1.46	0.70	−0.08	0.04
	Female gender	1.65	0.61	0.08	0.01
	Non-Hispanic blackc	0.31	0.97	0.01	0.75
	Hispanicc	1.07	1.16	0.03	0.35
	Other ethnicityc	3.90	1.38	0.08	0.00
	Years since amputation	−0.10	0.02	−0.16	<.0001
	Age	−0.05	0.02	−0.08	0.03
Fatigue	(Intercept)	50.89	1.58	-	<.0001	0.06	0.06
	Amputation transtibiala	0.35	0.59	0.02	0.55
	Traumatic etiologyb	−1.01	0.71	−0.05	0.15
	Female gender	2.23	0.61	0.11	0.00
	NonHispanic blackc	−1.34	0.98	−0.04	0.17
	Hispanicc	−1.01	1.17	−0.03	0.39
	Other ethnicityc	2.48	1.39	0.05	0.07
	Years since amputation	−0.12	0.02	−0.17	<.0001
	Age	−0.02	0.02	−0.03	0.34
Sleep disturbance	(Intercept)	55.16	1.55	-	<.0001	0.04	0.03
	Amputation transtibiala	0.01	0.58	0.00	0.99
	Traumatic etiologyb	−0.83	0.69	−0.05	0.23
	Female gender	1.17	0.60	0.06	0.05
	Non-Hispanic blackc	−0.43	0.96	−0.01	0.65
	Hispanicc	−0.68	1.14	−0.02	0.55
	Other ethnicityc	2.84	1.35	0.06	0.04
	Years since amputation	−0.05	0.02	−0.08	0.02
	Age	−0.09	0.02	−0.14	<.0001
Satisfaction with social role	(Intercept)	48.99	1.65	-	<.0001	0.09	0.08
	Amputation transtibiala	0.75	0.62	0.04	0.23
	Traumatic etiologyb	2.33	0.74	0.12	0.00
	Female gender	−0.47	0.64	−0.02	0.46
	Non-Hispanic blackc	0.89	1.03	0.03	0.39
	Hispanicc	−2.79	1.22	−0.07	0.02
	Other ethnicityc	−3.20	1.45	−0.07	0.03
	Years since amputation	0.14	0.02	0.19	<.0001
	Age	−0.07	0.03	−0.10	0.00
Pain interference	(Intercept)	56.52	1.51	-	<.0001	0.06	0.05
	Amputation transtibiala	0.89	0.57	0.05	0.12
	Traumatic etiologyb	−0.66	0.68	−0.04	0.33
	Female gender	1.74	0.58	0.09	0.00
	Non-Hispanic blackc	1.27	0.94	0.04	0.18
	Hispanicc	2.33	1.11	0.06	0.04
	Other ethnicityc	3.13	1.32	0.07	0.02
	Years since amputation	−0.09	0.02	−0.15	<.0001
	Age	−0.03	0.02	−0.05	0.18

Note:

^aReference group: Amputation transfemoral;

^bReference group: Dysvascular etiology;

^cReference group: non-Hispanic white.