Table 3.
The level of heterogeneity (I2) in the HPV type-specific summary prevalence ratios (PRs) within each phylogenetic group
| Grouping | List of HPV types | χ2 | DF | p | I2 (%) | Interpretation of heterogeneity |
|---|---|---|---|---|---|---|
| Phylogenetic | ||||||
| α3 | HPV61, 62, 72, 81, 83, 84, 89 | 18.48 | 6 | 0.005 | 67.54 | Substantial |
| α5 | HPV26, 51, 69, 82 | 1.07 | 3 | 0.785 | <0 | Not detectable |
| α6 | HPV53, 56, 66 | 3.00 | 2 | 0.223 | 33.32 | Small |
| α7 | HPV18, 39, 45, 59, 68, 70, 85 | 10.91 | 6 | 0.091 | 45.01 | Moderate |
| α9 | HPV16, 31, 33, 35, 52, 58, 67 | 17.39 | 6 | 0.008 | 65.49 | Substantial |
| α10 | HPV6, 11 | 5.71 | 1 | 0.017 | 82.49 | Substantial |
| α13 | HPV54, 55 | 0.04 | 1 | 0.838 | <0 | Not detectable |
| Carcinogenicity | ||||||
| Carcinogenic | HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59,68 | 28.39 | 12 | 0.005 | 57.73 | Substantial |
| Noncarcinogenic | HPV6, 11, 26, 32, 40, 53–55, 61, 62, 66, 67, 69–73,81–85, 89 | 53.39 | 22 | <0.001 | 58.79 | Substantial |
The level of heterogeneity was estimated using methods similar to those employed in meta-analysis. Specifically, the I2 statistic was obtained by adding an interaction between HPV type and HIV/CD4 strata in the GEE logistic regression models and then assessing the test statistics for the significance of this interaction.