Which Frailty Evaluation Method Can Better Improve the Predictive Ability of the SASA for Postoperative Complications of Patients Undergoing Elective Abdominal Surgery?

Figures & data

Table 1 Characteristics of the Patients at Baseline

Characteristics	Total (n=194)	FRAIL≥3 (n=85)	FI>0.4 (n=63)	CFS≥5 (n=71)
Anthropometrics/Demographics
Age (years), mean (SD)	77.0 (7.7)	81.9 (5.2)*	82.1 (5.7)*	81.7 (5.9)*
Male, n (%)	90 (46.4)	33 (38.8)	21 (33.3)*	26 (36.6)*
BMI (kg/m^2), mean (SD)	23.8 (2.2)	23.9 (2.2)	23.8 (2.3)	23.7 (2.2)
Education, n (%)		*	*	*
Illiterate	6 (3.1)	4 (4.7)	3 (3.5)	3 (4.2)
Elementary school	45 (23.2)	27 (31.8)	20 (23.5)	24 (33.8)
Junior/senior high school	125 (64.4)	51 (60)	39 (45.9)	43 (60.6)
Undergraduate	18 (9.3)	3 (3.5)	1 (1.2)	1 (1.4)
Type of surgery, n (%)
Gastrointestinal	75(38.7)	30(35.3)	27(42.9)	27(38.0)
Cholecystic	53(27.3)	29(34.1)	20(31.7)	25(35.2)
Epityphlon	31(16.0)	10(11.8)	5(7.9)	6(8.5)
Urinary system	18(9.3)	8(9.4)	5(7.9)	6(8.5)
Gynecology	17(8.8)	8(9.4)	6(9.5)	7(9.9)
Preoperative variables
Presence of malignancy, n (%)		*	*	*
None	107 (55.2)	48 (56.5)	31 (49.2)	35 (49.3)
Primary only	55 (28.4)	17 (20.0)	15 (23.8)	16 (22.5)
Metastases	32 (16.5)	20 (23.5)	17 (27.0)	20 (28.2)
Current smoker, n (%)	18 (9.3)	5 (5.9)	2 (3.2)*	2 (2.8)*
Current drinker, n (%)	12 (6.2)	5 (5.9)	4 (6.3)	4 (5.6)
CCI, mean (SD)	1.7 (1.2)	1.7 (1.3)	2.0 (1.5)	1.9 (1.4)
ADL, median (IQR)	85 (20)	75(10)*	70(15)*	70(15)*
ASA score		*	*	*
2	35 (18.0)	11 (12.9)	8 (12.7)	7 (9.9)
3	154 (79.4)	69 (81.2)	51 (81.0)	60 (84.5)
4	5 (2.6)	5 (5.9)	4 (6.3)	4 (5.6)
Surgical variables
Surgery duration (hours), median (IQR)	1.8(1.1)	1.8(0.8)	1.8(0.9)	1.9(1.0)
Total blood loss (mL), median (IQR)	200 (300)	200 (300)	200 (300)*	200 (300)*
Mean arterial pressure, mean (SD)	73.0 (10.0)	69.5 (10.5)*	68.2 (9.7)*	68.7 (10.6)*
Lowest heart rate, mean (SD)	68.3 (9.8)	71.7 (10.9)*	72.5 (11.4)*	72.1 (11.6)*
SASA, median (IQR)	14(3)	13(2)*	13(4)*	13(3)*

Note: *Significant difference can be seen between frail and non-frail group.

Abbreviations: BMI, body mass index; CCI, Charlson comorbidity index; ADL, activities of daily living; ASA, American Society of Anesthesiologists; FI, frailty index; CFS, clinical frailty scale.

Table 2 Association Between Frailty Category and In-Hospital Postoperative Complications

Complications/Classification	By FRAIL			By FI			By CFS
	Non-Frail	Frail	P-value	Non-Frail	Frail	P-value	Non-Frail	Frail	P-value
Complications, n	19	39	<0.001	23	35	<0.001	20	38	<0.001
Clavien-Dindo classification, n			0.001			0.002			<0.001
Grade 2	10	3		10	3		12	1
Grade 3	0	0		0	0		0	0
Grade 4	5	21		10	16		5	21
Grade 5	4	15		3	16		3	16

Table 3 Univariate Logistic Regression of Postoperative Complications in Hospital

Characteristic	OR (95% CI)	P-value
Demographic
Age	1.03 (0.99, 1.07)	0.164
Gender
Male	1.00	N/A
Female	1.64 (0.87, 3.07)	0.124
Education
Illiterate	1	N/A
Elementary	0.28 (0.05, 1.68)	0.162
Junior/senior high school	0.18 (0.03, 1.03)	0.053
Undergraduate	0.19 (0.03, 1.40)	0.104
Presence of malignancy
None	1.00	N/A
Primary only	2.13 (0.96, 4.73)	0.062
Metastases	30.71 (10.30, 91.55)	<0.001
Current smoking status	1.12 (0.38, 3.30)	0.837
Current drinking status	0.84 (0.24, 2.92)	0.789
BMI	1.13 (0.98, 1.31)	0.091
CCI	2.78 (1.66, 4.63)	<0.001
ADL	0.96 (0.94, 0.98)	<0.001
ASA	2.94 (1.25, 6.94)	0.014
Type of surgery
Gastrointestinal	1.00	N/A
Cholecystic	0.30 (0.13, 0.68)	0.004
Epityphlon	0.14 (0.04, 0.49)	0.002
Urinary system	0.64 (0.22, 1.88)	0.412
Gynecology	0.69 (0.23, 2.07)	0.513
Surgery variables
Surgery duration	1.97 (1.37, 2.83)	<0.001
Total blood loss	1.01 (1.01, 1.01)	<0.001
SASA	0.33 (0.24, 0.45)	<0.001
Frailty status (FRAIL)
Non-frail	1.00	N/A
Frail	4.02 (2.09, 7.72)	<0.001
Frailty status (FI)
Non-frail	1.00	N/A
Frail	5.87 (3.00, 11.48)	<0.001
Frailty status (CFS)
Non-frail	1.00	N/A
Frail	5.93 (3.04, 11.57)	<0.001

Table 4 Multiple Logistic Regression Analysis of In-Hospital Postoperative Complications

	Non-Adjusted OR (95% CI) P-value	Model I OR (95% CI) P-value	Model II OR (95% CI) P-value	Model III OR (95% CI) P-value
Frailty^a	4.02 (2.09, 7.72), <0.001	5.37 (2.28, 12.66), <0.001	4.77 (1.35, 16.90), 0.016	5.11 (1.41, 18.44), 0.013
Frailty^b	5.87 (3.00, 11.48),<0.001	7.53 (3.30, 17.22), <0.001	3.88 (1.14,13.22), 0.030	4.25 (1.21,14.90), 0.024
Frailty^c	5.93 (3.04, 11.57),<0.001	7.80 (3.42, 17.80), <0.001	5.02 (1.52,16.56), 0.008	5.10 (1.52, 17.17), 0.008
SASA	0.33 (0.24, 0.45), <0.001	0.31 (0.23, 0.44), <0.001	0.33 (0.21, 0.53), <0.001	0.32 (0.20, 0.51), <0.001

Notes: ^aFRAIL; ^bFI; ^cCFS. Model I:+age and gender; Model II:+ presence of malignancy, BMI, CCI, ADL, ASA, type of surgery, surgery duration, total blood loss; Model III:+all covariates.

Table 5 Performance of Risk Assessment Tool and Frailty Assessment Methods in Predicting Postoperative Complications

	Cox&Snell R^2	Nagelkerke R^2	Hosmer-Lemeshow χ2 (P-value)	AUC (95% CI)	ΔAUC (P-value)★*
SASA	0.194	0.276	10.531 (0.104)	0.768 (0.702, 0.826)
Frailty^a	0.082	0.117	4.176 (0.243)	0.684 (0.614, 0.749)	★0.1034
SASA+ Frailty^a	0.219	0.310	17.689 (0.024)	0.787 (0.722, 0.842)	*0.0186 (0.2802)
Frailty^b	0.119	0.169	22.276 (0.004)	0.728 (0.660, 0.789)	★0.4586
SASA+ Frailty^b	0.236	0.335	16.976 (0.030)	0.798 (0.734, 0.852)	*0.0296 (0.1455)
Frailty^c	0.168	0.239	3.805 (0.283)	0.753 (0.686, 0.812)	★0.7411
SASA+ Frailty^c	0.255	0.362	8.637 (0.280)	0.815 (0.753, 0.867)	*0.0471 (0.0478)

Notes: ^aFRAIL; ^bFrailty index; ^cClinical frailty score. ★Difference between SASA and any frailty evaluation method. *Difference between SASA and SASA +any frailty evaluation method.

Figure 1 Receiver operating characteristic (ROC) curves showing the predictive ability of three different frailty method and SASA.

Figure 2 Receiver operating characteristic (ROC) curves showing the predictive ability of three different frailty method+SASA and SASA.