Table 2. Quality assessment and subgroup analysis of HPV infection and esophageal carcinoma.
| Group | No. of Studies | Heterogeneity of ORs | Model used | Egger's test | ||||
|---|---|---|---|---|---|---|---|---|
| χ2 (df) | P | OR (95% CI) | χ2 | P | 95% CI | |||
| ALL | 33 | 78.4 | <0.001 | 1.45 (1.34–1.57) | REM | 2.05 | 0.058 | -0.01–2.64 |
| Area | ||||||||
| High | 13 | 31.93 (11) | <0.001 | 2.96 (2.01–4.34) | REM | 1.71 | 0.173 | -0.61–3.03 |
| Lower | 7 | 56.21 (7) | <0.001 | 3.57 (1.15–11.12) | REM | 0.37 | 0.443 | -2.90–5.68 |
| China | 21 | 31.93 (12) | <0.001 | 2.96 (2.01–4.35) | REM | 1.69 | 0.130 | -0.46–3.33 |
| Non-China | 12 | 56.21 (8) | <0.001 | 3.57 (1.15–11.13) | REM | 0.37 | 0.558 | -4.35–2.49 |
| Asia | 24 | 31.93 (13) | <0.001 | 2.96 (2.01–4.36) | REM | 1.73 | 0.090 | -0.24–0.017 |
| Non-Asia | 9 | 56.21 (9) | <0.001 | 3.57 (1.15–11.14) | REM | 0.37 | 0.091 | -0.67–7.04 |
| Method | ||||||||
| PCR | 18 | 20.39 (10) | 0.030 | 3.49 (2.49–4.90) | REM | 1.25 | 0.012 | 0.91–2.38 |
| IHC | 6 | 38.43 (5) | <0.001 | 4.76 (1.36–16.63) | REM | 0 | 0.659 | -5.02–7.10 |
| ELSIA | 4 | 20.02 (2) | <0.001 | 0.90 (0.13–6.48) | REM | 0 | 0.666 | -74.37–81.47 |
| ISH | 5 | 19.03(2) | <0.001 | 0.90 (0.15–6.42) | REM | 0 | 0.254 | -4.30–11.12 |
| Self | ||||||||
| Self | 14 | 56.09 (9) | <0.001 | 2.18 (1.02–4.66) | REM | 0.89 | 0.200 | -0.80–3.41 |
| NO | 19 | 36.69 (9) | <0.001 | 4.58 (2.69–7.80) | REM | 2.33 | 0.102 | -0.32–3.22 |
PCR: polymerase chain reaction; IHC: immunohistochemistry; ELISA: enzyme-linked immunosorbent assay; ISH: in situ hybridization; REM: random effects model; OR: odds ratio; CI: confidence interval.