Table 2.
Subgroup analysis of all studies
| Subgroups | No. of studies | Unadjusted OR | 95% CI | Adjusted OR | 95% CI | Heterogeneity between groups (p)* | |
|---|---|---|---|---|---|---|---|
| EC type | EAC + ESCC | 8 | 0.80 | 0.65–1.00 | 0.75 | 0.61–0.93 | 0.18 |
| EAC (patients with BE) | 5 | 0.57 | 0.44–0.75 | 0.59 | 0.45–0.78 | ||
| Study design | Case-control | 7 | 0.71 | 0.54–0.94 | 0.66 | 0.51–0.85 | 0.19 |
| Cohort | 5 | 0.76 | 0.60–1.00 | 0.79 | 0.62–1.02 | ||
| RCT (post-hoc analysis) | 1 | 0.98 | 0.69–1.40 | NR | NR | ||
| Publication type | Full text | 10 | 0.80 | 0.68–0.94 | 0.78 | 0.68–0.89 | 0.73 |
| Abstracts | 3 | NR | NR | 0.70 | 0.39–1.24 | ||
| Study location | USA | 6 | 0.67 | 0.48–0.92 | 0.68 | 0.48–0.95 | 0.30 |
| Europe | 5 | 0.85 | 0.70–1.03 | 0.82 | 0.72–0.93 | ||
| Study setting | Population-based | 8 | 0.76 | 0.61–0.95 | 0.71 | 0.57–0.88 | 0.82 |
| Hospital-based | 5 | 0.70 | 0.47–1.03 | 0.74 | 0.53–1.05 | ||
| Method of ascertainment to exposure | Pharmacy | 5 | 0.88 | 0.77–1.01 | 0.85 | 0.77–0.94 | 0.10 |
| EMR | 2 | 0.81 | 0.42–1.56 | 0.81 | 0.42–1.55 | ||
| Interview | 3 | 0.51 | 0.35–0.75 | 0.56 | 0.39–0.82 | ||
*
- for adjusted OR; EAC – Esophageal adenocarcinoma, ESCC – Esophageal squamous cell carcinoma, N/A – Not applicable, NR – Not reported