Table 1

The intergroup balance tests of possible confounding factors among different surgical techniques

		Surgical methods (in total sample) (n=516)					Surgical methods (in sample that survived) (n=340)
		Total	SA	EE	OC	P value	Total	SA	EE	OC	P value
Gender	Male	319	184	64	71	0.5539	212	114	54	44	0.1030
Gender	Female	197	120	41	36		128	77	36	15
Age (years)	<60	313	178	70	65	0.3407	236	131	67	38	0.4003
Age (years)	≥60	203	126	35	42		104	60	23	21
Consciousness	Drowsy	84	65	12	7	<0.0001*	66	51	11	4	<0.0001*
	Lethargic	127	82	31	14		110	71	27	12
	Light coma	213	122	53	38		130	65	44	21
	Deep coma	92	35	9	48		34	4	8	22
Smoking	Yes	130	72	31	27	0.4936	94	49	27	18	0.6474
Smoking	No	386	232	74	80		246	142	63	41
Diabetes	Yes	37	26	7	4	0.2458	23	14	5	4	0.8584
Diabetes	No	479	278	98	103		317	177	85	55
Hypertension	Yes	422	253	88	81	0.1855	284	161	75	48	0.8667
Hypertension	No	94	51	17	26		56	30	15	11
History of craniocerebral disease	Yes	63	37	14	12	0.8945	35	20	11	4	0.5605
History of craniocerebral disease	No	453	267	91	95		305	171	79	55
Herniation	Yes	84	29	10	45	<0.0001*	32	3	8	21	<0.0001*
Herniation	No	432	275	95	62		308	188	82	38
Interval between onset and operation (hours)	8 hours	132	80	17	35	0.0202*	68	37	14	17	0.1338
Interval between onset and operation (hours)	8 hours	384	224	88	72		272	154	76	42
Hematoma volume (mL)	>20–<40	161	131	18	12	<0.0001*	127	102	17	8	<0.0001*
	≥40–<80	253	134	69	50		168	82	57	29
	≥80	102	39	18	45		45	7	16	22
Rehabilitation treatment	PRT	184	108	42	34	0.1101	176	103	42	31	0.2318
	NPRT	128	68	41	19		124	66	40	18
	NRT	43	24	7	12		39	22	7	10
Decompressive craniectomy	Yes	112	21	11	80	<0.0001*	55	6	9	40	<0.0001*
Decompressive craniectomy	No	404	283	94	27		285	185	81	19
Tracheotomy	Yes	90	41	25	24	0.0174*	59	21	20	18	0.0009*
Tracheotomy	No	426	263	80	83		281	170	70	41
Lumbar puncture	Yes	111	42	47	22	<0.0001*	87	30	41	16	<0.0001*
Lumbar puncture	No	405	262	58	85		253	161	49	43
External lumbar drainage	Yes	54	31	15	8	0.2620	32	14	13	5	0.1568
External lumbar drainage	No	462	273	90	99		308	177	77	54

*P values show statistical significance.
EE, endoscopic evacuation; NPRT, non-professional rehabilitation treatment; NRT, no rehabilitation treatment; OC, open craniotomy; PRT, professional rehabilitation treatment; SA, stereotactic aspiration.