Early mortality and morbidity after total hip arthroplasty in patients with femoral neck fracture

Figures & data

Table 1. Baseline demographic information on the study population of 143,217 individuals (arthroplasty cases and controls)

Description of the study population	Controls		THA patients
	N	%	N	%
Sex
Male	29,827	25	6,259	25
Female	88,691	75	18,440	75
Age
60–69	21,443	18	4,453	18
70–79	49,985	42	10,304	42
80–89	42,171	36	8,852	36
90–99	4,919	4.2	1,090	4.4
CCI^a
0	100,957	85	16,131	65
1–2	14,467	12	6,998	28
> 2	3,094	2.6	1,570	6.4
Income^b
1st quarter	31,487	27	6,408	26
2nd quarter	30,658	26	6,828	28
3rd quarter	29,182	25	6,393	26
4th quarter	27,178	23	5,068	21
Education
None^c	10,913	9.2	2,242	9.1
9 years	62,262	53	13,426	54
High school	31,621	27	6,556	27
University	13,722	12	2,475	10

a CCI: Charlson comorbidity index.

b First quarter had the lowest income.

c No school education or level of education unknown.

Table 2. Crude survival for different time intervals with 95% confidence intervals, for controls and THA patients

	Controls		THA patients
	Survival	95% CI	Survival	95% CI
30-day survival	99.6	99.5–99.6	98.1	97.9–98.3
60-day survival	99.1	99.1–99.2	97.1	96.9–97.3
180-day survival	97.3	97.3–97.4	94.4	94.1–94.7
365-day survival	94.6	94.4–94.7	90.9	90.5–91.2

Table 4. Crude and adjusted risk of 90-day mortality with 95% confidence intervals. The adjusted hazard ratio (HR) for each variable was derived from a model adjusting for the other variables included in the model (i.e. gender, age, Charlson comorbidity index (CCI), personal income, and education). By definition, reference groups had an HR of 1

Risk of 90-day mortality	Crude HR	95% CI	Adj. HR	95% CI
Case^a
Arthroplasty	2.96	2.72–3.21	2.18	2.00–2.37
Sex^b
Female	0.69	0.63–0.75	0.71	0.65–0.78
Age^c
60–69	0.53	0.44–0.64	0.58	0.48–0.70
80–89	2.64	2.39–2.90	2.32	2.10–2.56
90–99	6.23	5.47–7.10	4.80	4.16–5.55
CCI^d
1–2	4.03	3.69–4.41	3.14	2.87–3.44
> 2	10.4	9.36–11.6	8.41	7.52–9.41
Income^e
2nd quarter	1.04	0.94–1.15	1.02	0.92–1.13
3rd quarter	0.88	0.79–0.98	0.95	0.85–1.06
4th quarter	0.57	0.50–0.65	0.84	0.73–0.97
Education^f
9 years	0.46	0.42–0.51	0.74	0.66–0.83
High school	0.31	0.27–0.35	0.57	0.49–0.66
University	0.24	0.20–0.29	0.50	0.41–0.61

a Reference = controls.

b Reference = male.

c Reference =70–79

d Reference =0.

e Reference = first quarter (lowest income).

f Reference = No school education or level of education unknown.

Figure 2. Unadjusted first-year survival functions of THA patients and controls. A. Females aged 70–79, CCI =0. B. Males aged 80–89, CCI =3 or more. 95% confi dence intervals are shaded, but they may appear so narrow as to be indistinguishable. Numbers at risk: A: 5,268 THA patients and 33,025 controls; B: 230 THA patients and 542 controls.

Table 5. Crude and adjusted risk of 90-day mortality with 95% confidence intervals in the subgroup of arthroplasty patients for whom information on ASA grade was available. The adjusted hazard ratio (HR) for each variable was derived from a model adjusting for the other variables included in the model (i.e. gender, age, Charlson comorbidity index (CCI), personal income, and education). By definition, reference groups had an HR of 1

Risk of 90-day mortality	Crude HR	95% CI	Adj. HR	95% CI
ASA^a
2	2.94	1.08–8.03	2.55	0.93–7.04
> 2	12.5	4.66–33.4	9.53	3.52–25.8
Sex^b
Female	0.54	0.47–0.61	0.48	0.36–0.62
Age^c
60–69	0.82	0.65–1.04	0.79	0.53–1.18
80–89	2.03	1.74–2.37	1.65	1.22–2.24
90–99	4.44	3.57–5.52	3.11	2.00–4.82
Income^d
2nd quarter	1.06	0.89–1.26	1.18	0.80–1.75
3rd quarter	0.95	0.79–1.13	0.97	0.66–1.45
4th quarter	0.76	0.62–0.93	1.12	0.73–1.71
Education^e
9 years	0.61	0.51–0.73	2.20	0.54–8.94
High school	0.45	0.36–0.56	1.75	0.43–7.20
University	0.37	0.28–0.51	1.38	0.32–5.88

a Reference = ASA grade 1.

b Reference = male.

c Reference =70–79 years.

d Reference = first quarter (lowest income).

e Reference = No school education or level of education unknown.