Table 1. Quality criteria for the included studies*.
| Quality parameter | Score | ||
|---|---|---|---|
| 2 | 1 | 0 | |
| Study design | Cohort study or nested case-control study | Incidence case-control study. Prevalence case-control study | - |
| No. of case subjects | >100 | 50-100 | <50 |
| Source of population | Community-based or from two or more countries | ≥2 hospitals | 1 hospitals |
| Mutation detection method | DNA direct sequencing | Innogenetics line-probe assay | Single-strand conformation polymorphism; Mass spectrometer |
| Matching of case and control subjects | |||
| Confounder group 1 | Age and sex | Age or sex | None |
| Confounder group 2 | HBeAg status and HBV genotype | HBeAg status or HBV genotype | None |
*
-, designs other than cohort or nested, incidence, or prevalence case-control not included in meta-analysis; HBeAg, hepatitis B e antigen; HBV, hepatitis B virus.