TABLE 3.
Subgroup analyses of the association between STAS and OS
| Test of association | Test of heterogeneity | Egger's test | Begg's test | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Studies | HR | 95%CI | p value | I 2 | p value | t (Bias) | p value | z | p value |
| Total | 11 | 2.02 | 1.78–2.29 | <0.001 | 15.0% | 0.297 | 1.32 | 0.216 | 1.03 | 0.304 |
| Treatment | ||||||||||
| Limited resection | 2 | 3.77 | 1.94–7.34 | <0.001 | 20.8% | 0.261 | – | – | 0.00 | 1.000 |
| Lobectomy | 2 | 1.56 | 0.98–2.48 | 0.061 | 0.0% | 0.581 | – | – | 0.00 | 1.000 |
| AJCC TNM | ||||||||||
| 7th | 3 | 2.43 | 1.70–3.46 | <0.001 | 18.1% | 0.282 | 2.29 | 0.242 | 0.00 | 1.000 |
| 8th | 8 | 1.96 | 1.71–2.25 | <0.001 | 0.0% | 0.372 | 0.41 | 0.554 | −0.10 | 1.000 |
| Research region | ||||||||||
| Korea | 2 | 1.17 | 0.51–2.70 | 0.715 | 0.0% | 0.907 | – | – | 0.00 | 1.000 |
| China | 4 | 1.94 | 1.68–2.24 | <0.001 | 30.6% | 0.217 | 1.06 | 0.365 | 1.22 | 0.221 |
| America | 1 | 1.88 | 1.07–3.30 | 0.028 | – | – | – | – | – | – |
| Japan | 3 | 2.75 | 1.91–3.96 | <0.001 | 0.0% | 0.462 | 6.14 | 0.103 | 1.04 | 0.296 |
| Hungary | 1 | 2.98 | 1.30–6.85 | 0.01 | – | – | – | – | – | – |
| Sample size | ||||||||||
| ≤400 | 5 | 2.39 | 1.74–3.28 | <0.001 | 0.0% | 0.466 | 0.38 | 0.79 | −0.24 | 1.000 |
| >400 | 6 | 1.95 | 1.698–2.25 | <0.001 | 25.60% | 0.234 | 0.61 | 0.496 | 0.60 | 0.548 |
Abbreviations: AJCC, American Joint Committee on Cancer; OS, overall survival; STAS, spread through air space; TNM, tumor, node, metastasis.