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Table 3 Subgroup analyses

From: The role of EGFR mutation as a prognostic factor in survival after diagnosis of brain metastasis in non-small cell lung cancer: a systematic review and meta-analysis

Group Number of cohorts HR and 95% CI P value Heterogeneity (%) P value for heterogeneity Ratio between subgroups P value between- subgroup
Country
 Eastern Countries 9 0.59 (0.37–0.92) 0.021 76.3 < 0.001 0.68 (0.38–1.21) 0.189
 Western Countries 10 0.87 (0.61–1.25) 0.455 81.6 < 0.001
Study design
 Prospective 3 0.81 (0.18–3.75) 0.792 83.7 0.002 1.16 (0.25–5.38) 0.852
 Retrospective 16 0.70 (0.55–0.89) 0.004 64.7 < 0.001
Disease status
 Adenocarcinoma 6 0.65 (0.36–1.18) 0.154 75.5 0.001 0.86 (0.43–1.72) 0.660
 Both 13 0.76 (0.53–1.10) 0.152 86.7 < 0.001
Sample size
 500 or more 2 0.52 (0.36–0.76) 0.001 49.4 0.160 0.68 (0.41–1.10) 0.117
 <  500 17 0.77 (0.56–1.06) 0.106 81.4 < 0.001
Mean age (years)
 65.0 or older 4 0.59 (0.36–0.98) 0.043 73.2 0.011 0.65 (0.35–1.19) 0.160
 <  65.0 11 0.91 (0.65–1.28) 0.595 78.0 < 0.001
Percentage male (%)
 50.0 or greater 12 0.81 (0.55–1.19) 0.290 86.2 < 0.001 1.35 (0.82–2.23) 0.242
 <  50.0 7 0.60 (0.43–0.82) 0.002 42.9 0.105
Percentage of current/past smokers (%)
 50.0 or greater 11 0.78 (0.52–1.17) 0.239 87.5 < 0.001 1.50 (0.64–3.50) 0.349
 <  50.0 5 0.52 (0.25–1.11) 0.092 81.1 < 0.001
Percentage of patients using TKI (%)
 30.0 or greater 9 0.60 (0.48–0.75) < 0.001 26.2 0.211 0.59 (0.32–1.10) 0.099
 <  30.0 4 1.01 (0.57–1.81) 0.963 87.3 < 0.001
Study quality
 High 10 0.67 (0.50–0.90) 0.007 58.0 0.011 0.85 (0.47–1.53) 0.585
 Low 9 0.79 (0.47–1.31) 0.357 88.3 < 0.001
  1. CI confidence intervals, HR hazards ratios, TKI tyrosine kinase inhibitor, bold entries P<0.05