Table 3.

Subgroup analysis for the association between different levels of troponin-I (all compared to Group I as a reference) and hospital mortality. The following variables were used as covariates in the model: age, APACHE II, sex, admission diagnosis, diabetes, chronic liver disease, chronic respiratory disease, chronic renal diseases, chronic immunosuppression, vasopressor use, sepsis, cardiac arrest, acute kidney injury, Glasgow Coma Scale, platelet, INR, bilirubin and lactic acid levels) Interaction test was performed for each subgroup

	Group II 0.03–0.3 ng/ml			Group III 0.3–3 ng/ml			Group IV >3 ng/ml
Subgroups	aOR (95% CI)	P value	P valuefor interaction	aOR (95% CI)	P value	P value for interaction	aOR (95% CI)	P value	P value for interaction
Age
< 50	1.72 (1.06, 2.78)	0.03	0.02	2.86 (1.68, 4.85)	0.0001	0.03	4.71 (2.55, 8.72)	<0.0001	0.0005
≥ 50	0.87 (0.64,1.17)	0.34		1.28 (0.91,1.80)	0.16		1.20 (0.82,1.77)	0.35
Gender
Male	0.99 (0.72,1.35)	0.95	0.50	1.68 (1.18, 2.39)	0.004	0.82	1.64 (1.10, 2.44)	0.02	0.63
Female	1.23 (0.82,1.86)	0.32		1.59 (1.00, 2.53)	0.05		2.16 (1.22, 3.81)	0.008
Sepsis
Yes	1.07 (0.66,1.74)	0.78	0.77	1.73 (1, 2.99)	0.05	0.95	1.69 (0.90, 3.17)	0.10	0.74
No	1.11 (0.83, 1.49)	0.47		1.68 (1.21, 2.33)	0.002		1.85 (1.26, 2.72)	0.002
Vasopressors
Yes	0.81 (0.55, 1.19)	0.28	0.24	0.97(0.64,1.47)	0.88	0.008	0.94 (0.59,1.49)	0.78	0.002
No	1.22 (0.87, 1.71)	0.24		2.39 (1.62, 3.53)	<0.0001		3.23 (1.97, 5.28)	<0.0001
Admission category
Non-operative	1.02 (0.77, 1.35)	0.91	0.53	1.48 (1.07, 2.03)	0.02	0.29	1.5 (1.03, 2.17)	0.03	0.07
Post-operative	1.47 (0.85, 2.55)	0.17		2.74 (1.48, 5.07)	0.001		3.29 (1.62, 6.71)	0.001
Chronic liver disease
Yes	0.79 (0.38, 1.64)	0.53	0.37	1.23 (0.51, 2.97)	0.65	0.52	3.19 (0.84,12.16)	0.09	0.4584
No	1.13 (0.87, 1.48)	0.36		1.74 (1.29, 2.34)	0.0003		1.82 (1.29, 2.56)	0.0006
Advanced heart failure
Yes	1.24 (0.71, 2.18)	0.45	0.63	2.29 (1.23, 4.26)	0.009	0.30	1.38 (0.73, 2.63)	0.32	0.23
No	1.04 (0.79,1.37)	0.79		1.52 (1.11, 2.09)	0.01		2.11 (1.43, 3.12)	0.0002
Chronic respiratory disease
Yes	0.76 (0.41, 1.42)	0.39	0.53	1.29 (0.65, 2.56)	0.47	0.64	1.2 (0.49, 2.95)	0.69	0.55
No	1.13 (0.86, 1.48)	0.39		1.70 (1.25, 2.32)	0.0007		1.85 (1.30, 2.63)	0.0006
Chronic renal disease
Yes	0.98 (0.44, 2.18)	0.96	0.94	2.27 (0.95, 5.42)	0.07	0.33	1.37 (0.55, 3.42)	0.50	0.45
No	1.09 (0.84, 1.41)	0.52		1.52 (1.13, 2.05)	0.006		1.94 (1.36, 2.75)	0.0002
Chronic immunosuppression
Yes	0.85 (0.45, 1.60)	0.61	0.19	1.49 (0.68, 3.28)	0.32	0.36	1.36 (0.49, 3.74)	0.55	0.37
No	1.11 (0.85, 1.46)	0.43		1.68 (1.24, 2.28)	0.0007		1.87 (1.32, 2.64)	0.0005
Diabetes
Yes	0.94 (0.63, 1.42)	0.77	0.76	1.05 (0.66,1.66)	0.84	0.05	1.05 (0.64,1.73)	0.84	0.01
No	1.1 (0.8,1.50)	0.57		2.12 (1.49, 3.02)	<0.0001		2.80 (1.79, 4.38)	<0.0001
Acute Kidney injury
Yes	1.02 (0.49, 2.12)	0.97	0.97	1.17 (0.54, 2.52)	0.70	0.23	1.27 (0.55, 2.95)	0.5811	0.33
No	1.08 (0.82,1.4)	0.59		1.8 (1.33, 2.44 )	0.0002		1.92 (1.34, 2.76)	0.0004
Chronic hypertension
Yes	1.08 (0.74,1.58)	0.70	0.64	1.4 (0.91, 2.15)	0.13	0.57	1.37 (0.85, 2.2)	0.20	0.15
No	1.01 (0.73,1.4)	0.96		1.79 (1.24, 2.59)	0.002		2.23 (1.41, 3.51)	0.0006
Cardiac arrest
Yes	4.21 (0.68, 26.19)	0.12	0.23	4.92 (0.79, 30.77)	0.09	0.50	6.48 (1.02, 41.23)	0.05	0.43
No	1.03 (0.80, 1.33)	0.81		1.62 (1.21, 2.16)	0.001		1.74 (1.23, 2.46)	0.002