Table 3.

Modeling of CHI3L1/YKL-40 With and Without IL-6 and CRP (a comparison of models) and Their Association With Delirium

Marker	Models 1: Individual Models	Model 2: Single Multivariable Model
	RR (95% CI)	RR (95% CI)
PREOP:
YKL-40
Q1	Reference	Reference
Q2	2.0 (1.1–3.9)	1.9 (1.0a–3.6)
Q3	2.5 (1.4–4.7)	2.2 (1.1–4.3)
Q4	2.9 (1.6–5.5)	2.4 (1.2–5.0)
p-for trend	<.01	.03
CRP
Q1	Reference	Reference
Q2	1.2 (0.7–2.2)	1.3 (0.7–2.3)
Q3	1.6 (1.0b–2.8)	1.5 (0.8–2.6)
Q4	1.8 (1.0 c –3.0)	1.4 (0.8–2.4)
p-for trend	.02	.23
POD2:
YKL-40
Q1	Reference	Reference
Q2	1.2 (0.7–2.2)	0.9 (0.5–1.7)
Q3	1.8 (1.0 d –3.1)	1.2 (0.6–2.1)
Q4	2.0 (1.1–3.4)	1.1 (0.5–2.1)
p-for trend	<.01	.66
CRP
Q1	Reference	Reference
Q2	1.1 (0.7–2.0)	1.0 (0.6–1.8)
Q3	1.5 (0.9–2.5)	1.2 (0.7–2.0)
Q4	1.5 (0.9–2.5)	1.0 (0.6–1.7)
p-for trend	.06	.99
IL-6
Q1	Reference	Reference
Q2	1.5 (0.8–2.8)	1.5 (0.8–2.7)
Q3	2.0 (1.1–3.5)	1.8 (0.9–3.3)
Q4	2.3 (1.3–4.1)	2.1 (1.1–4.1)
p-for trend	<.01	.02

Notes: All models adjusted for age, sex, surgery type, Charlson comorbidity index, medical complications, and baseline general cognitive performance.

Bold indicates significant at p < .05.

CHI3L1/YKL-40 (ng/l): PREOP - Q1 ≤38.97, Q2 38.98–70.80, Q3 70.81–122.69, Q4 ≥122.70; POD2 – Q1 ≤286.74, Q2 286.75–542.84, Q3 54.85–1040.66, Q4 ≥1040.67.

CRP (mg/l): POD2 - Q1 ≤127.53, Q2 127.54–177.05, Q3 177.06–235.73, Q4 ≥235.74.

IL-6 (mg/l): POD2 – Q1 ≤110.12, Q2 110.13–127.53, Q3 127.54–169.22, Q4 ≥265.4.

Model 1: CHI3L1/YKL-40 PREOP (N = 553), CHI3L1/YKL-40 POD2 (N = 556), CRP PREOP (N = 553), CRP POD2 (N = 556), IL6 POD2 (N = 555).

Model 2: N = 547.

CHI3L1/YKL-40 = Chitinase-3-like protein 1; CI = Confidence interval; CRP = C-reactive protein; IL6 = Interleukin-6; POD2 = Postoperative day 2; PREOP = Preoperative; RR = Relative risk.

Actual values: ^a0.97, ^b0.96, ^c1.04, ^d1.02.