Prediction of Postoperative Delirium After Cardiac Surgery with A Quick Test of Cognitive Speed, Mini-Mental State Examination and Hospital Anxiety and Depression Scale

Figures & data

Table 1 Comparing Preoperative and Perioperative Characteristics of Patients Who Developed Postoperative Delirium and Those Who Did Not Among 218 Patients Undergoing Cardiac Surgery at Two Participating Thoracic Surgery Centers in South Sweden

	Delirium (n=47)	Non-Delirium (n=171)	p-value
Age, years (median, range)	76 (61–85)	71 (50–85)	0.010
Age, 77 years or more, n	18 (38%)	34 (20%)	0.009
Women/Men, n	13/34 (21/22%)	46/125 (79/78%)	0.92
Diabetes, n	16 (34%)	43 (25)	0.22
Smoking, n	1 (2%)	18 (10)	0.071
Alcohol, n	8 (17%)	46 (27)	0.39
Memory complaints, n	13 (28%)	40 (23)	0.56
MMSE score (median, range)	27 (19–30)	28 (20–30)	0.009
MMSE score <27 points, n	20 (43%)	33 (19%)	0.001
AQT-color-form, seconds (median, range)	76 (48–181)	70 (40–182)	0.030
AQT-color-form >70 seconds, n	32 (71%)	86 (51%)	0.015
AQT-form, seconds (median, range)	44 (23–171)	40 (20–80)	0.058
AQT-form, >35 seconds, n	10 (22%)	39 (23%)	0.83
HADS-D, score (median, range)	3 (0–12)	2 (0–14)	0.13
HADS-D >4 points, n	14 (30%)	24 (14%)	0.012
HADS-A, score (median, range)	4 (0–14)	4 (0–14)	0.36
EQ5D, tto score (median, range)	0.771 (0.389–1.0)	0.818 (0.022–1.0)	0.038
EQ5D, tto score <0.771, n	27 (57%)	68 (40%)	0.030
EuroQoL barometer, mm (median, range)	60 (20–99)	68 (0–100)	0.11
EuroQoL barometer, <61 mm, n	29 (62%)	70 (42%)	0.015
Type of surgery, n			0.022*
CABG*	23 (49%)	106 (62%)	0.10**
Valve only*	10 (21%)	42 (25%)	0.63**
Valve+CABG*	14 (30%)	22 (13%)	0.006**
Cardiopulmonary bypass time, minutes (median, range)	112.5 (39–474)	94 (28–433)	0.011

Notes: Mann–Whitney’s and Chi-square tests. *3x2 Chi-square test; **2x2 Chi-square test - each surgery variable vs two other combined.

Abbreviations: MMSE, Mini-Mental State Examination; AQT, A Quick Test of Cognitive Speed; HADS-D, The Hospital Anxiety and Depression Scale-Depression; HADS-A, The Hospital Anxiety and Depression Scale-Anxiety; CABG, coronary artery bypass graft; CPB, cardiopulmonary bypass.

Table 2 Multivariable Analysis of Risk Factors Associated with Postoperative Delirium

Variables	OR	95% CI	p
MMSE <27 points	2.72	1.27–5.86	0.010
AQT color and form >70 seconds	2.26	1.03–4.95	0.043
HAD-D >4 points	2.60	1.21–5.58	0.014
Cardiopulmonary bypass time, minutes	1.007	1.002–1.013	0.007

Notes: The Hosmer-Lemeshow test: p = 0.469.

Abbreviations: MMSE, Mini-Mental State Examination; AQT, A Quick Test of Cognitive Speed; HADS-D, The Hospital Anxiety and Depression Scale-Depression; CPB, cardiopulmonary bypass.

Figure 1 ROC curve for the probabilities from logistic modeling using MMSE (>27 points), AQT color and form (>70 seconds), HADS-D (>4 points) and cardiopulmonary by-pass-time. The AUC (95% CI) was 0.736 (0.65–0.82).