Table 2.

Summary of the subgroup analysis results of beta-blocker use and OS

Variables	Number of studies	Number of patients	Model	Outcome (OS)		Heterogeneity
				HR (95% CI)	P-value	I2 (%)	P-value
Ethnicity
Non-Europeans	16	30,607	R	0.90 (0.78–1.02)	0.106	87.2	<0.001
Europeans	8	12,182	R	1.00 (0.89–1.12)	0.958	72.2	0.001
Duration of drug use
>2 years	6	8,899	F	1.03 (0.93–1.14)	0.617	0.0	0.576
<2 years	6	10,812	R	1.01 (0.91–1.11)	0.897	54.7	0.051
Cancer stage
I/II	11	2,870	F	0.97 (0.89–1.06)	0.507	15.6	0.295
III/IV	13	4,835	R	1.04 (0.94–1.14)	0.468	59.1	0.003
Sample size
>1,500	15	65,834	R	1.01 (0.94–1.08)	0.783	76.7	<0.001
<1,500	18	11,839	R	0.81 (0.66–1.00)	0.053	83.5	<0.001
Beta-blocker type
Non-selective	12	17,714	R	1.04 (0.89–1.22)	0.596	75.7	<0.001
Selective	10	17,714	R	0.93 (0.83–1.05)	0.243	83.5	<0.001
Chronological order of drug use
Pre-diagnostic beta-blocker use	13	55,710	R	1.03 (0.95–1.11)	0.493	74.7	<0.001
Post-diagnostic beta-blocker use (time-fixed)	7	6,372	R	0.65 (0.43–0.99)	0.046	91.0	<0.001
Post-diagnostic beta blocker use (time-dependent)	2	2,406	R	0.87 (0.59–1.30)	0.508	76.8	0.038
Cancer type
Lung cancer	7	10,189	F	1.01 (0.96–1.05)	0.818	40.1	0.124
Melanoma	2	4,910	F	0.81 (0.67–0.97)	0.026	0.0	0.892
Mixed cancer	4	21,494	R	1.00 (0.83–1.21)	0.974	87.7	<0.001
Colorectal cancer	2	4,202	R	1.16 (0.84–1.61)	0.353	51.3	0.152
Ovarian cancer	5	3,140	R	0.59 (0.36–0.96)	0.034	88.0	<0.001
Breast cancer	6	16,637	R	0.97 (0.78–1.21)	0.783	61.20	0.024
Pancreatic cancer	2	16,096	R	0.85 (0.75–0.97)	0.014	71.10	0.063

Abbreviations: F, fixed-effects model; R, random-effects model; OS, overall survival.