(a) Subgroup comparisons for Helicobacter pylori infection on the risk of esophageal squamous cell carcinoma |
| | Subgroup | No. of studies | (%) | Overall OR (95% CI) | value§ | | DL | HKSJ | | Esophageal squamous cell carcinoma |
| | Case/control (2,063/35,051) | | | | | | | All studies | 21 | 78.5 | 0.84 (0.64, 1.09) | 0.74 (0.54, 0.97) | | | Ethnicity | | | | | 0.144 | | Caucasians | 11 | 70.8 | 0.80 (0.54, 1.17) | 0.73 (0.48, 1.11) | | | Mongolians | 8 | 86.9 | 0.89 (0.56, 1.41) | 1.13 (0.79, 1.60) | | | Negroes | 1 | — | 0.34 (0.07, 1.58) | — | | | Australian | 1 | — | 1.18 (0.84, 1.65) | — | | | Study area | | | | | <0.001 | | North America | 2 | 0 | 1.83 (1.17, 2.87) | 1.79 (0.25, 12.9) | | | East Asia | 8 | 86.9 | 0.89 (0.56, 1.41) | 1.13 (0.79, 1.60) | | | Europe | 7 | 0.9 | 0.84 (0.65, 1.10) | 0.72 (0.46, 1.12) | | | Middle East | 3 | 0 | 0.34 (0.22, 0.52) | 0.34 (0.26, 0.44) | | | Oceania | 1 | — | 1.18 (0.84, 1.65) | — | | | Study type | | | | | 0.250 | | Case-control | 19 | 80 | 0.85 (0.65, 1.13) | 0.70 (0.51, 0.97) | | | Cohort | 2 | 49 | 0.59 (0.19, 1.86) | 0.80 (0.0, 967.18) | | | Study object | | | | | 0.005 | | Population-based studies | 14 | 79.5 | 0.93 (0.68, 1.28) | 0.91 (0.66, 1.24) | | | Clinical-based studies | 7 | 72.5 | 0.66 (0.40, 1.07) | 0.53 (0.28, 0.99) | | | Matching | | | | | 0.290 | | Studies with matched controls | 2 | 86.5 | 0.87 (0.30, 2.52) | 1.14 (0.0, 563.04) | | | Studies without matched controls | 19 | 78.7 | 0.83 (0.63, 1.11) | 0.71 (0.52, 0.96) | | | Helicobacter pylori detection method | | | | | 0.003 | | Serology | 16 | 81.4 | 0.83 (0.61, 1.12) | 0.83 (0.61, 1.14) | | | Rapid urease test | 2 | 0 | 0.39 (0.22, 0.69) | 0.35 (0.17, 0.69) | | | Serology, histology, and rapid urease test | 3 | 0 | 1.32 (0.87, 2.01) | 1.33 (0.72, 2.44) | |
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Note: DL: DerSimonian-Laird; HKSJ: Hartung-Knapp-Sidik-Jonkman. §Differences between subgroups; the difference was statistically significant. |
(b) Subgroup comparisons for Helicobacter pylori infection on the risk of esophageal adenocarcinoma |
| | Subgroup | No. of studies | (%) | Overall OR (95% CI) | value§ | | DL | HKSJ | | Esophageal adenocarcinoma |
| | Case/control (7687/301085) | | | | | | | All studies | 20 | 73.4 | 0.55 (0.43, 0.70) | 0.23 (0.15, 0.36) | | | Ethnicity | | | | | <0.001 | | Caucasians | 18 | 33.9 | 0.60 (0.50, 0.73) | 0.23 (0.14, 0.37) | | | Mixed race | 1 | — | 0.29 (0.25, 0.35) | — | | | Australian | 1 | — | 0.52 (0.36, 0.76) | — | | | Study area | | | | | 0.100 | | North America | 11 | 80.5 | 0.62 (0.42, 0.93) | 0.54 (0.35, 0.81) | | | Europe | 7 | 56.2 | 0.49 (0.34, 0.69) | 0.13 (0.06, 0.27) | | | Middle East | 1 | — | 0.32 (0.10, 1.02) | — | | | Oceania | 1 | — | 0.52 (0.36, 0.76) | — | | | Study type | | | | | 0.287 | | Case-control | 19 | 74.4 | 0.56 (0.44, 0.72) | 0.23 (0.14, 0.37) | | | Cohort | 1 | — | 0.23 (0.06, 0.83) | — | | | Study object | | | | | <0.001 | | Population-based studies | 11 | 37.9 | 0.59 (0.48, 0.73) | 0.15 (0.08, 0.28) | | | Clinical-based studies | 9 | 73.4 | 0.52 (0.35, 0.79) | 0.47 (0.29, 0.77) | | | Matching | | | | | <0.001 | | Studies with matched controls | 5 | 0 | 0.73 (0.57, 0.92) | 0.71 (0.60, 0.84) | | | Studies without matched controls | 15 | 73.3 | 0.48 (0.36, 0.65) | 0.21 (0.13, 0.36) | | | Helicobacter pylori detection method | | | | | <0.001 | | Serology | 14 | 36.3 | 0.62 (0.51, 0.75) | 0.19 (0.11, 0.32) | | | Histology | 5 | 62.1 | 0.39 (0.26, 0.60) | 0.39 (0.18, 0.84) | | | Serology, histology | 1 | — | 0.81 (0.32, 2.07) | — | |
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Note: DL: DerSimonian-Laird; HKSJ: Hartung-Knapp-Sidik-Jonkman. §Differences between subgroups; the difference was statistically significant. |
