Developing a nomogram for postoperative delirium in elderly patients with hip fractures

Table 1 Baseline data, n

Variable	Total	Non-delirium group (n = 453)	Delirium group (n = 79)	χ2/t	P value
Age, years	78.00 [74.00, 82.00]	77.68 ± 4.84	81.33 ± 4.72	6.313	< 0.001
Gender
Male	359	308	51	0.362	0.548
Female	173	145	28
Fracture type
Femoral neck fracture	312	267	45	0.109	0.742
Femoral intertrochanteric fracture	220	186	34
Body mass index, kg/m2	23.44 ± 2.30	23.36 ± 2.17	23.94 ± 2.93	1.695	0.093
History of cognitive impairment
With	19	14	5	2.049	0.152
Without	513	439	74
Smoking history
With	224	195	29	1.108	0.292
Without	308	258	50
Preoperative comorbidities
With	317	267	50	0.529	0.467
Without	215	186	29
Number of comorbidities
≥ 2	473	408	65	4.138	0.042
< 2	59	45	14
Hypertension
With	222	186	36	0.563	0.453
Without	310	267	43
Diabetes
With	73	63	10	0.089	0.766
Without	459	390	69
COPD
With	51	45	6	0.056	0.812
Without	481	408	73
Walking ability before injury
Normal	372	322	50	2.446	0.294
Mild limitation	85	68	17
Inability to walk	75	63	12
ASA grading
1-2	381	335	46	8.182	0.004
3-4	151	118	33

COPD: Chronic obstructive pulmonary disease; ASA: American Society of Anesthesiologists.