Increased early mortality and morbidity after total hip arthroplasty in patients with socioeconomic disadvantage: a report from the Swedish Hip Arthroplasty Register

Figures & data

Table 1. Description of the study population

Factor	Number	%
Total	166,076
Women	93,855	57
Men	72,221	43
Median age at index surgery (range)	70 (16–100)
Median follow-up, years (range)	7 (0–22)
Year of surgery
1992–1998	44,746	27
1999–2005	54,222	33
2006–2012	67,108	40
Income
Low	57,397	35
Middle	55,151	33
High	53,528	32
Education
Low	78,422	47
Middle	57,594	35
Higher	30,060	18
Cohabiting status
Cohabiting	97,257	59
Non-cohabiting	68,819	41
Immigration status
Non-immigrant	153,403	92
Immigrant	12,673	8
Charlson Comorbidity Index
Low	139,197	84
Moderate	23,925	14
High	2,954	2
Hospital type
County	125,801	76
Private	21,342	13
University	18,933	11
Implant fixation
Cemented	136,554	82
Uncemented	13,233	8
Other^a	16,289	10
Revision after index surgery
No	157,698	95
Yes	8,378	5

a Hybrid, reversed hybrid, and resurfacing.

Table 2. Hazard ratio (HR) for mortality up to 30 days after THA

Factor	%	n	Crude HR (95% CI)	p-value	Adjusted HR (95% CI)	p-value
Age
	0.1	16	Ref.		Ref.
60–75 years	0.1	115	2.2 (1.3–3.7)	0.003	1.7 (1.0–2.8)	0.05
	0.5	264	9.3 (5.6–15.4)	< 0.001	5.1 (3.1–8.6)	< 0.001
Sex
Female	0.2	176	Ref.		Ref.
Male	0.3	219	1.6 (1.3–2.0))	< 0.001	1.9 (1.5–2.4)	< 0.001
Year of surgery
1992–1998	0.4	174	Ref.		Ref.
1999–2005	0.2	123	0.6 (0.5–0.7)	< 0.001	0.6 (0.5–0.8)	0.001
2006–2012	0.1	98	0.4 (0.3–0.5)	< 0.001	0.3 (0.3–0.4)	< 0.001
Income
Low	0.4	213	Ref.		Ref.
Middle	0.2	127	0.6 (0.5–0.8)	< 0.001	0.7 (0.6–0.9)	0.006
High	0.1	55	0.3 (0.2–0.4)	< 0.001	0.5 (0.3–0.7)	< 0.001
Education
Low	0.3	261	Ref.		Ref.
Middle	0.2	100	0.5 (0.4–0.7)	< 0.001	0.9 (0.7–1.1)	0.4
Higher	0.1	34	0.3 (0.2–0.5)	< 0.001	0.8 (0.6–1.2)	0.4
Cohabiting status
Cohabiting	0.2	191	Ref		Ref.
Non-cohabiting	0.3	204	1.5 (1.2–1.8)	< 0.001	1.4 (1.1–1.8)	0.001
Immigration status
Non-immigrant	0.2	374	Ref.		Ref.
Immigrant	0.2	21	0.7 (0.4–1.1)	0.1	0.8 (0.5–1.2)	0.3
Charlson Comorbidity Index
Low	0.1	193	Ref.		Ref.
Moderate	0.7	159	4.8 (3.9–5.9)	< 0.001	4.4 (3.6–5.4)	< 0.001
High	1.5	43	10.6 (7.6–14.7)	< 0.001	9.9 (7.0–13.9)	< 0.001
Hospital type
County	0.3	314	Ref.		Ref.
Private	0.1	25	0.5 (0.3–0.7)	< 0.001	0.9 (0.6–1.3	0.5
University	0.3	56	1.2 (0.9–1.6)	0.2	1.0 (0.8–1.4	0.9

Number of events = 395; adjusted for age, sex, year of surgery, income, education, cohabiting status, immigration status, Charlson Comorbidity Index and hospital type.

Table 3. Level of income and education divided by Charlson Comorbidity Index. Values are frequency (%)

Charlson Comorbidity Index
Factor	Low	Moderate	High
Income
Low	47,581 (83)	8,822 (15)	994 (2)
Middle	45,440 (82)	8,559 (16)	1,152 (2)
High	46,176 (86)	6,544 (12)	808 (2)
Level of education
Low	64,849 (83)	12,098 (15)	1,475 (2)
Middle	48,442 (84)	8,119 (14)	1,033 (2)
Higher	25,906 (86)	3,708 (12)	446 (2)