Association between anesthesia technique and complications after hip surgery in the elderly population

Table 1 Baseline characteristics of all patients

	Total (n = 718)		Spinal anaesthesia (n = 579)		General anaesthesia (n = 139)		Standardised difference	P value
	n/mean	%/SD	n/mean	%/SD	n/mean	%/SD
Age (yr)1	84.76	5.38	85.23	5.33	82.82	5.15	-0.529	< 0.001
Sex							-0.023	0.521
Female	532	74.1	426	73.6	106	76.3
Male	186	25.9	153	26.4	33	23.7
ASA1 classification							-0.322	< 0.001
1	0	0	0	0	0	0
2	85	11.8	56	9.7	29	20.97
3	575	80.1	473	81.7	102	73.4
4	55	7.7	47	8.1	8	5.8
5	0	0	0	0	0	0
Position type1							-0.619	< 0.001
Lateral decubitus position	282	39.3	199	34.5	83	59.7
Prone position	9	1.3	8	1.4	1	0.7
Supine position	134	18.7	106	18.4	28	20.1
Traction position	285	39.7	258	44.8	27	19.4
Others	5	0.7	5	0.9	0	0
Operation time (min)1	69.80	35.34	67.10	31.47	80.98	46.70	0.322	0.001
Anaesthesia time (min)1	117.48	45.84	113.13	42.50	135.54	54.22	0.458	< 0.001
Blood loss (mL)1	68.85	82.86	60.71	61.96	102.55	134.55	0.402	< 0.001
NNIS1							-0.292	< 0.001
0	214	29.8	155	26.8	59	42.4
1	496	69.1	420	72.5	76	54.7
2	8	1.1	4	0.7	4	2.9
CCI1	5.14	1.47	5.23	1.48	4.77	1.41	-0.368	0.001
Comorbidities
Respiratory system	88	12.3	77	13.3	11	7.9	-0.265	0.085
Circulatory system	533	74.2	429	74.1	104	74.8	0.027	0.914
Digestive system	91	12.7	72	12.4	19	13.7	0.069	0.695
Urogenital system	67	9.3	56	9.7	11	7.9	-0.008	0.627
Blood system	20	2.8	14	2.4	6	4.3	0.098	0.248
Endocrine system	207	28.8	167	28.8	40	28.8	-0.000	1.000
Autoimmune system	7	1	5	0.9	2	1.4	-0.020	0.626
Nervous system	20	2.8	14	2.4	6	4.3	0.067	0.248
Cerebrovascular system	193	26.9	162	28	31	22.3	-0.108	0.201
Facial features	8	1.1	7	1.2	1	0.7	-0.020	1.000
Mental disorders	10	1.4	9	1.6	1	0.7	-0.073	0.696
Osteoporosis	13	1.8	10	1.7	3	2.2	0.031	0.724
Tumour	62	8.6	51	8.8	11	7.9	-0.001	0.744
Operation	272	37.9	216	37.3	56	40.3	0.035	0.559
Blood transfusion	26	3.6	20	3.5	6	4.3	0.015	0.801
Laboratory examination
Urea	7.71	6.18	7.78	6.05	7.43	6.71	-0.039	0.581
Creatinine1	90.13	66.24	91.95	71.04	82.40	39.20	-0.161	0.049
e-GFR	64.82	21.16	64.07	21.36	67.96	20.07	0.194	0.075

¹P < 0.05. ASA: American Society of Anaesthesiologists; CCI: Comprehensive complication index; eGFR: Estimated glomerular filtration rate; NNIS: National nosocomial infection surveillance.