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

Table 2 Baseline characteristics in propensity score-matched cohorts

	Total (n = 309)		Spinal anaesthesia (n = 206)		General anaesthesia (n = 103)		Standardised difference	P value
	n/mean	%/SD	n/mean	%/SD	n/mean	%/SD
Age (yr)	84.23	5.12	84.33	5.21	84.04	4.95	-0.128	0.644
Sex							-0.021	0.401
Female	239	77.3	158	76.7	81	78.6
Male	70	22.7	48	23.3	22	21.4
ASA classification							-0.117	0.873
1	0	0	0	0	0	0
2	33	10.7	20	9.7	13	12.6
3	260	84.1	178	86.4	82	79.6
4	16	5.2	8	3.9	8	7.8
5	0	0	0	0	0	0
Position type							-0.114	0.261
Lateral decubitus position	150	48.5	95	46.1	55	53.4
Prone position	5	1.6	4	1.9	1	1.0
Supine position	56	18.1	34	16.5	22	21.4
Traction position	97	31.4	72	35	25	24.3
Others	1	0.3	1	0.5	0	0
Operation time (min)	76.10	33.1	77.23	31.90	73.81	35.50	-0.033	0.391
Anaesthesia time (min)	125.05	39.8	124.31	38.84	126.41	41.94	-0.034	0.672
Blood loss (mL)	75.71	67.0	72.48	62.96	82.18	74.22	-0.032	0.230
NNIS							0.050	0.635
0	40	12.9	6	29.6	34	33
1	213	68.9	143	69.4	67	65
2	4	1.3	2	1.0	2	1.9
CCI	5.05	1.4	5.09	1.39	4.97	1.39	0.033	0.470
Comorbidities
Respiratory system	37	12.0	28	13.6	9	8.7	0.062	0.266
Circulatory system	232	70.1	153	74.3	79	76.7	0.026	0.678
Digestive system	40	12.9	24	11.7	16	15.5	-0.046	0.370
Urogenital system	26	8.4	18	8.7	8	7.8	0.055	0.832
Blood system	10	3.2	6	2.9		3.9	-0.025	0.736
Endocrine system	83	26.9	55	26.7	28	27.2	-0.025	1.000
Autoimmune system	3	1.0	2	1.0	1	1.0	0.024	1.000
Nervous system	9	2.9	5	2.4	4	3.9	0.014	0.488
Cerebrovascular system	80	25.9	55	26.7	25	24.3	0.079	0.681
Facial features	4	1.3	3	1.5	1	1.0	0.047	1.000
Mental disorders	3	1.0	2	1.0	1	1.0	0.062	1.000
Osteoporosis	8	2.6	6	2.9	2	1.9	0.076	0.723
Tumour	23	7.4	14	6.8	9	8.7	0.008	0.646
Operation	117	37.9	77	37.4	40	38.8	0.189	0.901
Blood transfusion	14	4.5	8	3.9	6	5.8	-0.220	0.562
Laboratory examination
Urea	7.30	4.8	7.49	5.43	6.90	3.27	0.060	0.360
Creatinine	8.64	65.4	91.85	76.31	81.92	31.79	0.018	0.143
e-GFR	64.45	21.2	63.5	21.69	66.37	20.24	-0.036	0.313

ASA: American Society of Anaesthesiologists; CCI: Comprehensive complication index; e-GFR: Estimated glomerular filtration rate. NNIS: National nosocomial infection surveillance.