Table 3.

Subgroup analyses for presence of distant metastasis, local recurrence, TNM stage, and disease progression. CI, confidence interval; HR, hazard ratio; PS, propensity score; TNM, tumour–node–metastasis

Stratified variable	Anaesthesia	Crude HR (95% CI)	P-value	P=value (interaction)	PS-adjusted HR (95% CI)	P=value	PS-matched HR (95% CI)		P=value
Non-stratified
	Desflurane	1.00			1.00			1.00
	Propofol	0.28 (0.23–0.34)	<0.001		0.41 (0.33–0.50)	<0.001		0.47 (0.38–0.59)	<0.001
Metastasis				0.002
No	Desflurane	1.00			1.00			1.00
	Propofol	0.27 (0.22–0.34)	<0.001		0.39 (0.32–0.49)	<0.001		0.47 (0.37–0.60)	<0.001
Yes	Desflurane	1.00			1.00			1.00
	Propofol	0.66 (0.41–1.07)	0.088		0.60 (0.37–0.98)	0.040		0.73 (0.43–1.23)	0.224
Recurrence				<0.001
No	Desflurane	1.00			1.00			1.00
	Propofol	0.12 (0.09–0.18)	<0.001		0.28 (0.19–0.42)	<0.001		0.22 (0.14–0.34)	<0.001
Yes	Desflurane	1.00			1.00			1.00
	Propofol	0.59 (0.47–0.74)	<0.001		0.71 (0.56–0.89)	0.003		0.98 (0.76–1.27)	0.884
TNM stage				0.909
TNM: I+II	Desflurane	1.00			1.00			1.00
	Propofol	0.27 (0.21–0.36)	<0.001		0.39 (0.29–0.53)	<0.001		0.41 (0.29–0.56)	<0.001
TNM: III+IV	Desflurane	1.00			1.00			1.00
	Propofol	0.32 (0.24–0.42)	<0.001		0.40 (0.30–0.52)	<0.001		0.47 (0.35–0.64)	<0.001
Cancer-specific mortality
	Desflurane	1.00			1.00			1.00
	Propofol	0.38 (0.31–0.47)	<0.001		0.60 (0.48–0.74)	<0.001		0.55 (0.44–0.69)	<0.001
Disease progression
Local recurrence	Desflurane	1.00			1.00			1.00
	Propofol	0.31 (0.26–0.37)	<0.001		0.39 (0.32–0.47)	<0.001		0.42 (0.34–0.52)	<0.001
Distant metastasis	Desflurane	1.00			1.00			1.00
	Propofol	0.13 (0.08–0.20)	<0.001		0.41 (0.25–0.69)	0.001		0.25 (0.15–0.41)	<0.001
Local recurrence + Distant metastasis	Desflurane	1.00			1.00			1.00
	Propofol	0.32 (0.27–0.38)	<0.001		0.43 (0.36–0.52)	<0.001		0.44 (0.36–0.54)	<0.001