No influence of immigrant background on the outcome of total hip arthroplasty

Figures & data

Table 1. Patient data based on ethnicity

Variables	Born in Sweden n (%)	Born in the Nordic countries excl. Sweden n (%)	Born in Europe excl. the Nordic countries and the former Soviet Union n (%)	Born outside Europe including the former Soviet Union n (%)
Sex
M	56,480 (40.3)	2,029 (31.7)	1,416 (35.3)	417 (36.9)
F	83,818 (59.7)	4,367 (68.3)	2,597 (64.7)	713 (63.1)
Age ^a	69.7 (69.7–69.8)	67.8 (67.6–68.1)	67.1 (66.8–67.5)	61.4 (60.5–62.4)
< 50	5,864 (4.2)	298 (4.7)	288 (7.2)	298 (26.4)
50–59	17,798 (12.7)	955 (14.9)	593 (14.8)	168 (14.9)
60–69	38,468 (27.4)	2,102 (32.9)	1,250 (31.1)	225 (19.9)
70–79	52,690 (37.6)	2,355 (26.8)	1,424 (35.5)	304 (26.9)
≥ 80	25,479 (18.2)	686 (10.7)	458 (11.4)	135 (11.9)
Diagnoses
Primary OA	108,966 (77.7)	4,925 (77.0)	3,221 (80.3)	732 (64.8)
Inflammatory disease	5,275 (3.8)	283 (4.4)	131 (3.3)	51 (4.5)
Fracture	18,032 (12.9)	817 (12.8)	363 (9.0)	125 (11.1)
Pediatric hip disease	2,212 (1.6)	121 (1.9)	146 (3.6)	126 (11.2)
Idiopathic femoral head necrosis	4,297 (3.1)	201 (3.1)	116 (2.9)	73 (6.5)
Others without tumor	1,517 (1.1)	49 (0.8)	36 (0.9)	23 (2.0)
Cohabiting
Yes	81,319 (58.0)	3,439 (53.8)	2,267 (56.5)	621 (55.0)
No	58,980 (42.0)	2,957 (46.2)	1,746 (43.5)	509 (45.0)
Education (ISCED 97)
Low	94,331 (67.2)	4,188 (65.5)	2,126 (53.0)	667 (59.0)
Middle	32,188 (22.9)	1,688 (26.4)	1,264 (31.5)	272 (24.1)
High	13,780 (9.8)	520 (8.1)	623 (15.5)	191 (16.9)
Comorbidity ^b
Elixhauser 0	100,065 (71.5)	4,385 (68.8)	2,864 (71.5)	817 (72.6)
Elixhauser ≥1	39,808 (28.5)	1,984 (31.2)	1,139 (28.5)	309 (27.4)
Type of fixation
Cemented	124,502 (89.0)	5,538 (86.8)	3,370 (84.3)	777 (69.2)
Uncemented	6,120 (4.4)	380 (6.0)	292 (7.3)	182 (16.2)
Hybrid	5,557 (4.0)	269 (4.2)	186 (4.7)	68 (6.1)
Inverse hybrid	3,004 (2.1)	179 (2.8)	122 (3.1)	80 (7.1)
Hip resurfacing	761 (0.5)	15 (0.2)	29 (0.7)	16 (1.4)

^a mean (95% CI).

^b no comorbidity (0) or 1 or more comorbidities according to Elixhauser.

Table 2. Reoperation within 2 years. Hazard ratios according to regression analysis

Variables	HR	95% CI	p-value
Countries of birth (unadjusted)
Born in Sweden ^a	1
Born in the Nordic countries ^b	1.07	0.89–1.29	0.5
Born in Europe ^c	0.73	0.56–0.97	0.03
Born outside Europe ^d	1.16	0.77–1.75	0.5
Countries of birth (adjusted)
Born in Sweden ^a	1
Born in the Nordic countries ^b	1.09	0.91–1.31	0.4
Born in Europe ^c	0.76	0.58–1.01	0.05
Born outside Europe ^d	1.00	0.66–1.53	1.0
Sex
M	1.42	1.31–1.54	< 0.001
F	1
Age, years
< 50	0.84	0.67–1.05	0.1
50–59	1.04	0.90–1.19	0.6
60–69	0.95	0.85–1.06	0.4
70–79	1
≥ 80	1.02	0.91–1.13	0.8
Diagnosis
Primary OA ^a	1
Inflammatory disease	1.30	1.05–1.57	0.01
Fracture	2.72	2.47–2.99	< 0.001
Pediatric hip disease	1.56	1.19–2.06	< 0.001
Idiopatic femoral head necrosis	2.03	1.69–2.43	< 0.001
Others without tumor	2.12	1.58–2.84	< 0.001
Cohabiting
Yes	1.15	1.06–1.25	0.001
No ^a	1
Educational level (ISCED 97)
Low ^a	1
Middle	1.07	0.92–1.24	0.4
High	1.03	0.88–1.20	0.7
Comorbidities
Elixhauser 0 ^a	1
Elixhauser ≥ 1	1.41	1.30–1.52	< 0.001
Type of fixation
Cemented ^a	1
Uncemented	1.56	1.29–1.87	< 0.001
Hybrid	1.19	0.97–1.46	0.09
Inverse hybrid	2.06	1.67–2.53	< 0.001
Hip resurfacing	2.82	1.92–4.14	< 0.001

^a reference group.

^b excluding Sweden.

^c excluding the Nordic countries and the former Soviet Union.

^d including the former Soviet Union.

Table 3. Revision within 14 years. Hazard ratios according to regression analysis

Variables	HR	95% CI	p-value
Countries of birth (unadjusted)
Born in Sweden ^a	1
Born in the Nordic countries ^b	1.14	1.02–1.27	0.03
Born in Europe ^c	1.08	0.94–1.24	0.3
Born outside Europe ^d	1.49	1.18–1.88	0.001
Countries of birth (unadjusted)
Born in Sweden ^a	1
Born in the Nordic countries ^b	1.09	0.98–1.23	1.0
Born in Europe ^c	1.01	0.88–1.16	0.9
Born outside Europe ^d	1.04	0.82–1-31	0.8
Sex
M	1.42	1.35–1.49	< 0.001
F ^a	1
Age, years
< 50	2.20	1.99–2.44	< 0.001
50–59	1.72	1.59–1.86	< 0.001
60–69	1.32	1.24–1.41	< 0.001
70–79	1
≥ 80	0.83	0.75–0.91	< 0.001
Diagnosis
Primary OA ^a	1
Inflammatory disease	1.11	0.99–1.24	0.6
Fracture	1.80	1.67–1.94	< 0.001
Pediatric hip disease	1.49	1.31–1.70	< 0.001
Idiopatic femoral head necrosis	1.47	1.30–1.67	< 0.001
Others without tumor	1.38	1.15–1.65	< 0.001
Cohabiting
Yes ^a	1
No	0.98	0.93–1.03	0.5
Educational level (ISCED 97)
Low ^a	1
Middle	0.94	0.87–1.01	0.1
High	0.96	0.89–1.04	0.4
Comorbidities
Elixhauser 0 ^a	1
Elixhauser ≥ 1	1.14	1.06–1.20	< 0.001
Type of fixation
Cemented ^a	1
Uncemented	1.42	1.29–1.56	< 0.001
Hybrid	1.40	1.29–1.53	< 0.001
Inverse hybrid	1.29	1.08–1.54	0.004
Hip resurfacing	1.66	1.20–2.30	0.002

^a reference group.

^b excluding Sweden.

^c excluding the Nordic countries and the former Soviet Union.

^d including the former Soviet Union.