Is preoperative anxiety associated with postoperative delirium in older persons undergoing cardiac surgery? Secondary data analysis of a randomized controlled trial

Table 3 Risk factors for delirium

Risk factor	Unadjusted OR (95% CI)	Adjusted OR (95% CI)
Main model ^a
Treatment allocation	0.87 (0.49–1.55)	1.19 (0.61–2.32)
Age	1.09 (1.04–1.15)	1.10 (1.03–1.18) *
Mini-Mental State Examination	0.88 (0.77–1.01)	0.90 (0.77–1.06)
Geriatric Depression Scale	1.05 (0.88–1.26)	1.04 (0.84–1.29)
Katz ADL index	0.95 (0.73–1.25)	0.69 (0.50–0.96) *
EuroSCORE 2	1.13 (1.06–1.21)	1.07 (0.99–1.15)
Time on cardiopulmonary bypass	1.01 (1.00–1.02)	1.01 (1.00–1.02) *
Diabetes mellitus	2.05 (1.05–3.97)	3.15 (1.42–7.00) *
Postoperative infection	2.46 (1.23–4.93)	1.90 (0.87–4.12)
Anxiety measures ^b
APAIS, anxiety score ^c	0.98 (0.91–1.06)	0.97 (0.88–1.07)
APAIS, need for information score ^d	0.91 (0.81–1.03)	0.95 (0.83–1.10)
Visual Analogue Scale, anaesthesia ^e	1.00 (0.99–1.02)	1.00 (0.99–1.02)
Visual Analogue Scale, surgery ^f	0.99 (0.98–1.01)	1.00 (0.98–1.01)

* Statistical significant at p < 0.05
^a Performance of the main model: Pseudo R2 = 0.17, C-index = 0.77, Discrimination slope = 0.21 GOF chi2 = 34.98, p = 0.760, Mean VIF = 1.18;
^b Anxiety measures were tested seperately in four different models: model 1 = Main model + APAIS anxiety score, model 2 = Main model + APAIS need for information score, model 3 = Main model + Visual Analogue Scale anaesthesia, model 4 = Main model + Visual Analogue Scale surgery
^c Performance of Main model + APAIS anxiety score (in comparison with main model): Δ R2 = 0, Δ C-index = 0, Δ Discrimination slope = 0; GOF chi2 = 5.88, p = 0.661
^d Performance of Main model + APAIS need for information score (in comparison with main model): Δ R2 = 0, Δ C-index = 0, Δ Discrimination slope = 0; GOF chi2 = 5.94, p = 0.654
^e Performance of Main model + Visual Analogue Scale anaesthesia (in comparison with main model): Δ R2 = 0, Δ C-index = 0, Δ Discrimination slope = 0; GOF chi2 = 7.03, p = 0.534
^f Performance of Main model + Visual Analogue Scale surgery (in comparison with main model): Δ R2 = 0, Δ C-index = 0, Δ Discrimination slope = 0; GOF chi2 = 6.56, p = 0.585
Abbreviations: APAIS Amsterdam Preoperative Anxiety and Information Scale, ADL activities of daily living

ISSN: 1471-2318