Table 2 Subgroup Analyses of the Associations between LMR and overall survival
Variables | No. of studies | Test of association | Test of heterogeneity | |||
|---|---|---|---|---|---|---|
HR | 95% CI | P value | I2 (%) | P value | ||
Total | 35 | 0.578 | 0.522–0.641 | < 0.001 | 70.10 | < 0.001 |
Publication year | ||||||
 ≤ 2016 | 18 | 0.572 | 0.497–0.660 | < 0.001 | 67.20 | < 0.001 |
 > 2016 | 17 | 0.583 | 0.499–0.681 | < 0.001 | 72.60 | < 0.001 |
Initial inclusion period | ||||||
 ≤ 2006 | 19 | 0.554 | 0.480–0.640 | < 0.001 | 72.90 | < 0.001 |
 > 2006 | 16 | 0.604 | 0.516–0.707 | < 0.001 | 68.20 | < 0.001 |
Research region | ||||||
 Asia | 28 | 0.584 | 0.520–0.656 | < 0.001 | 74.90 | < 0.001 |
 Europe | 5 | 0.553 | 0.446–0.685 | < 0.001 | 0.00 | 0.712 |
 America and others | 2 | 0.584 | 0.459–0.744 | < 0.001 | 0.00 | 0.596 |
Number of cases | ||||||
 < 200 | 19 | 0.632 | 0.547–0.730 | < 0.001 | 63.20 | < 0.001 |
 > 200 | 16 | 0.549 | 0.497–0.606 | < 0.001 | 41.30 | 0.043 |
Median age (years) | ||||||
 ≤ 60 | 13 | 0.585 | 0.496–0.691 | < 0.001 | 69.20 | < 0.001 |
 > 60 | 13 | 0.575 | 0.488–0.679 | < 0.001 | 75.70 | < 0.001 |
 NR | 9 | 0.557 | 0.427–0.727 | < 0.001 | 62.60 | 0.006 |
Tumor types | ||||||
 Breast cancer | 1 | 0.47 | 0.171–1.295 | 0.144 | – | – |
 Cervical carcinoma | 1 | 0.337 | 0.164–0.691 | 0.003 | – | – |
 Colon cancer and rectal cancer | 13 | 0.579 | 0.516–0.650 | < 0.001 | 0.00 | 0.496 |
 Ovarian cancer | 1 | 0.615 | 0.527-0.718 | < 0.001 | – | – |
 Esophageal cancer | 1 | 0.495 | 0.315– 0.778 | 0.002 | – | – |
 Gastric cancer | 2 | 0.664 | 0.523–0.843 | 0.001 | 0.00 | 0.622 |
 Head and neck cancer | 1 | 0.28 | 0.168–0.466 | < 0.001 | – | – |
 Hepatocellular carcinoma | 1 | 0.73 | 0.399–1.336 | 0.308 | – | – |
 Lung cancer | 5 | 0.594 | 0.435–0.811 | 0.001 | 85.50 | < 0.001 |
 Nasopharyngeal carcinoma | 2 | 0.479 | 0.406–0.566 | < 0.001 | 0.00 | 0.379 |
 Pancreatic cancer | 5 | 0.588 | 0.407–0.851 | 0.005 | 67.90 | 0.014 |
 Renal cancer | 2 | 0.827 | 0.755–0.906 | < 0.001 | 0.00 | 0.7 |
LMR cutoff | ||||||
 < 3.0 | 9 | 0.508 | 0.444–0.582 | < 0.001 | 16.00 | 0.3 |
 ≥ 3.0 | 26 | 0.612 | 0.546–0.686 | < 0.001 | 69.80 | < 0.001 |
Therapeutic strategies | ||||||
 Chemotherapy | 10 | 0.592 | 0.518–0.676 | < 0.001 | 31.90 | 0.153 |
 Molecular targeted | 2 | 0.622 | 0.304–1.271 | 0.193 | 93.00 | < 0.001 |
 Surgery | 10 | 0.683 | 0.579–0.807 | < 0.001 | 54.30 | 0.02 |
 Combined therapy | 11 | 0.507 | 0.442–0.582 | < 0.001 | 37.90 | 0.097 |
 Others | 2 | 0.563 | 0.400–0.794 | 0.001 | 0.00 | 0.577 |
Follow-up period (months) | ||||||
 ≤ 33 | 13 | 0.545 | 0.454–0.653 | < 0.001 | 67.80 | < 0.001 |
 > 33 | 9 | 0.594 | 0.515–0.685 | < 0.001 | 15.60 | 0.303 |
 NR | 13 | 0.606 | 0.504–0.729 | < 0.001 | 81.10 | < 0.001 |
Quality score | ||||||
 < 7 | 3 | 0.753 | 0.592–0.958 | 0.021 | 83.20 | 0.003 |
 ≥ 7 | 32 | 0.558 | 0.504–0.619 | < 0.001 | 58.30 | < 0.001 |
Analysis of hazard ratio | ||||||
 Multivariate | 32 | 0.562 | 0.503–0.628 | < 0.001 | 68.70 | < 0.001 |
 Univariate | 3 | 0.755 | 0.643–0.887 | 0.001 | 23.30 | 0.272 |