Table 2. Association between PD-L1 expression and driver gene status among different clinicopathological conditions.

Driver gene	Subgroup	Studies	OR	95% CI	p	Heterogeneity test
						Q	I2	p1	p2
EGFR
	Median age(years)
	≥60	16	0.56	0.35–0.89	0.013	64.05	76.6%	0.000	0.109
	<60	4	1.18	0.70–2.00	0.526	6.84	56.1%	0.077
	Gender
	Male > Female	16	0.68	0.41–1.12	0.129	62.45	76.0%	0.000	0.720
	Male ≤ Female	8	0.55	0.33–0.94	0.030	29.33	76.1%	0.000
	Smoking status
	Smoker > non-Smoker	13	0.52	0.29–0.96	0.035	52.76	77.3%	0.000	0.129
	Smoker ≤ non-Smoker	9	0.82	0.53–1.27	0.367	31.64	74.7%	0.000
	Cutoff
	1% cutoff	3	0.35	0.22–0.55	0.000	1.25	0.0%	0.536	0.440
	5% cutoff	16	0.68	0.43–1.08	0.104	83.17	82.0%	0.000
	10% cutoff	2	0.54	0.15–1.88	0.332	1.16	13.6%	0.282
	50% cutoff	5	0.33	0.14–0.81	0.015	2.31	0.0%	0.679
	Race
	East-Asian	17	0.68	0.48–0.98	0.037	59.26	73.0%	0.000	0.711
	Other	7	0.45	0.14–1.48	0.188	53.85	75.4%	0.000
	Primary antibody
	PoAba	6	0.93	0.46–1.90	0.852	21.55	76.8%	0.001	0.150
	MoAbb	17	0.50	0.33–0.75	0.001	61.91	74.2%	0.000
	Historical type
	ADCc	12	0.69	0.43–1.10	0.119	60.32	81.8%	0.000	0.833
	SCCd	2	0.55	0.15–2.02	0.365	1.23	18.4%	0.268
	Stage
	I–II	12	0.73	0.45–1.19	0.207	42.67	74.2%	0.000	0.525
	III–IV	2	1.38	0.71–2.69	0.344	0.95	0.0%	0.400
	Quality
	Me	22	0.67	0.47–0.97	0.033	91.05	76.9%	0.000	0.187
ALK
	Median age(years)
	≥60	8	1.74	0.99–3.07	0.056	3.32	0.0%	0.854	/
	<60	2	0.95	0.37–2.43	0.968	1.30	23.2%	0.254
	Gender
	Male > Female	6	1.39	0.77–2.49	0.272	1.45	0.0%	0.919	/
	Male ≤ Female	5	1.41	0.74–2.68	0.301	4.69	14.7%	0.321
	Smoking status
	Smoker > non-Smoker	5	1.23	0.58–2.57	0.591	2.04	0.0%	0.728	/
	Smoker ≤ non-Smoker	5	1.51	0.84–2.70	0.168	3.82	0.0%	0.432
	Cutoff
	5% cutoff	7	1.62	0.99–2.63	0.054	3.45	0.0%	0.750	/
	50% cutoff	2	1.08	0.17–6.96	0.569	0.32	0.0%	0.569
	Race
	East-Asian	7	1.52	0.93–2.47	0.095	5.06	0.0%	0.536	/
	Other	4	1.02	0.39–2.66	0.962	0.66	0.0%	0.883
	Historical type
	ADC	7	1.30	0.78–2.17	0.138	3.33	0.0%	0.650	/
KRAS
	Median age (years)
	≥60	12	1.58	1.23–2.04	0.000	8.51	0.0%	0.667	/
	<60	2	0.71	0.25–2.00	0.517	1.32	24.0%	0.251
	Gender
	Male > Female	12	1.34	1.04–1.72	0.025	10.38	0.0%	0.497	/
	Male ≤ Female	4	1.77	1.19–2.62	0.004	1.81	0.0%	0.613
	Smoking status
	Smoker > non-Smoker	8	1.35	1.03–1.77	0.032	7.8	10.3%	0.350	/
	Smoker ≤ non-Smoker	6	1.16	0.70–1.19	0.576	4.52	0.0%	0.477
	Cutoff
	1% cutoff	2	1.84	1.23–2.74	0.003	0.88	0.0%	0.347	/
	5% cutoff	10	1.35	1.00–1.86	0.049	10.21	11.9%	0.333
	50% cutoff	5	1.32	0.93–1.89	0.13	0.83	0.0%	0.935
	Race
	East-Asian	9	1.24	0.78–1.96	0.358	7.15	0.0%	0.520	/
	Other	7	1.54	1.20–1.96	0.001	5.69	0.0%	0.459
	Historical type
	ADC	8	1.69	1.20–2.39	0.003	7.65	8.5%	0.364	/
	SCC	2	0.51	0.09–3.07	0.464	0.26	0.0%	0.609

Note: a: “PoAb” represents “polyclonal antibody”; b: “McAb” represents “monoclonal antibody”; c: “ADC” represents adenocarcinoma; d: “SCC” represents squamous-cell carcinoma; e: “M” represents moderate quality; 1: p for heterogeneity within each subgroup; 2: p for heterogeneity between subgroups with meta-regression analysis.