Table 3.

Univariate and multivariate analysis for variables significantly associated with postoperative delirium

Variables	n	Delirium (n = 29)	Crude RR (95% CI)	p-value	Adjusted RR (95% CI)	p-value
Pre-existing dementia, n (%)
No	207	13 (6.3)	1		1
Yes	42	16 (38.1)	6.07 (3.16–11.65)	< 0.001	3.95 (1.91–8.17)	< 0.001
Age ≥ 75 years, n (%)
No	124	6 (4.8)	1		1
Yes	125	23 (18.4)	3.80 (1.60–9.03)	0.001	2.54 (1.11–5.80)	0.027
Preoperative hematocrit <30%, n (%)
No	214	21 (9.8)	1		1
Yes	35	8 (22.9)	2.33 (1.12–4.84)	0.042	1.53 (0.79–2.96)	0.204
Preoperative opioids, n (%)
No	213	18 (8.5)	1		1
Yes	36	11 (30.6)	3.62 (1.87–7.01)	0.001	1.80 (0.83–3.91)	0.139
Preoperative benzodiazepines, n (%)
No	212	20 (9.4)	1		1
Yes	37	9 (24.3)	2.58 (1.27–5.22)	0.022	1.41 (0.66–3.01)	0.370
Preoperative infection, n (%)
No	225	23 (10.2)	1		1
Yes	24	6 (25.0)	2.45 (1.11–5.41)	0.044	1.47 (0.68–3.19)	0.329
Barthel Index score ≤ 70, n (%)
No	198	16 (8.1)	1		1
Yes	51	13 (25.5)	3.15 (1.62–6.13)	0.001	1.14 (0.54–2.40)	0.734

A p-value < 0.05 indicates statistical significance

Abbreviations: RR risk ratio, CI confidence interval