Table 2 Risk factors of PONV using stepwise forward regression and full model (n = 205)

Age

0.98 (0.94–1.01)

0.188

-0.08

0.93 (0.87–0.99)

0.015^c

Female sex

2.70 (1.43–5.08)

0.002^c

2.64 (1.16–6.00)

0.021^c

0.94

2.55 (0.61–10.59)

0.198

BMI

0.90 (0.85–0.96)

0.001^c

-0.01

1.00 (0.88–1.13)

0.979

ASA classification

 II

1

Ref

Ref

 III

5.55 (2.92–10.53)

< 0.001^c

-0.69

0.50 (0.12–2.13)

0.349

Apfel risk score

 0

1

Ref

Ref

 1

1.50 (0.28–8.14)

0.638

0.51

1.66 (0.13–21.42)

0.699

 2

3.42 (0.70–16.76)

0.129

0.45

1.58 (0.08–31.69)

0.767

 3

3.21 (0.64–16.18)

0.157

0.33

1.38 (0.05–35.52)

0.844

 4

 N/A

> 0.999

43.65

 N/A

> 0.999

Diabetes mellitus

0.37 (0.20–0.70)

0.002^c

0.24 (0.11–0.55)

0.001^c

-0.98

0.38 (0.11–1.30)

0.123

Hypertension

0.95 (0.48–1.89)

0.893

0.58

1.79 (0.59–5.39)

0.301

Smoking

0.37 (0.17–0.81)

0.012^c

-0.57

0.57 (0.11–2.95)

0.501

His_PONV

N/A

> 0.999

-1.06

 N/A

> 0.999

His_MS

N/A

> 0.999

-22.21

 N/A

> 0.999

Type of surgery

 LSG

1

Ref

Ref

 LSG-JJB

0.29 (0.15–0.54)

< 0.001^c

1.39

4.02 (0.82–19.85)

0.088

 LSG-DJB

N/A

> 0.999

-19.28

 N/A

> 0.999

 OAGB

0.21 (0.02–1.96)

0.171

-18.87

 N/A

> 0.999

Dur_anesthesia

0.21 (0.09–0.49)

< 0.001^c

-3.18

0.04 (0.01–5.62)

0.204

Dur_operation

0.23 (0.10–0.54)

0.001^c

-4.88

0.01 (0.01–5.83)

0.150

IOC

0.94 (0.90–0.98)

0.002^c

3.95

51.69 (0.34–7843.66)

0.124

PHC

0.68 (0.38–1.22)

0.196

-0.46

0.63 (0.25–1.57)

0.323

Sugammadex

0.05 (0.02–0.12)

< 0.001^c

0.03 (0.01–0.09)

< 0.001^c

-4.27

0.01 (0.01–0.06)

< 0.001^c

Total fluid input

0.99 (0.98–1.00)

0.003^c

-0.01

1.00 (1.00–1.00)

0.270

Rescue opioids

0.82 (0.46–1.44)

0.484

 N/A