Table 3.
Effect of study characteristics on the association between Salmonella and gallbladder cancer (GBC) in a meta‐analysis of the published literature
| Summary effect estimatea | Ratio of effect estimates | |||||
|---|---|---|---|---|---|---|
| Study characteristic | N studies | Cochrane's Q P‐value | RR | 95% CI | Ratio of RRs | 95% CI |
| Salmonella detection method | ||||||
| VI antibody seropositivity | 7 | 0.6 | 4.6 | 3.1–6.8 | 1.0 | |
| Bile culture | 5 | 0.1 | 4.7 | 1.5–14.6 | 1.0 | 0.5–2.4 |
| Stool culture | 2 | 0.4 | 5.5 | 3.0–10.4 | 1.2 | 0.6–2.5 |
| Self‐report | 2 | 0.8 | 1.3 | 0.9–2.0 | 0.3 | 0.2–0.5 |
| Referent group | ||||||
| Stones (gallstones and/or bile duct) | 10 | 0.2 | 2.5 | 1.4–4.2 | 1.0 | |
| General populationb | 6 | 0.6 | 5.1 | 3.4–7.6 | 1.9 | 0.7–4.8 |
| Hepatobiliary patients | 4 | 0.005 | 2.1 | 0.4–11.0 | 0.9 | 0.3–2.9 |
| Nonhepatobiliary patients and cadavers | 6 | 0.003 | 5.5 | 2.2–13.9 | 2.2 | 0.8–5.9 |
| Study design | ||||||
| Case–control | 12 | 0.6 | 4.6 | 3.3–6.4 | 1.0 | |
| Cohort | 2 | 0.3 | 2.7 | 1.1–6.6 | 0.6 | 0.2–1.5 |
| Region | ||||||
| Asia | 8 | 0.5 | 4.3 | 3.0–6.3 | 1.0 | |
| Central/South America | 4 | 0.4 | 2.5 | 1.0–6.3 | 0.6 | 0.2–1.6 |
| Population | ||||||
| Hospital | 9 | 0.5 | 4.4 | 3.0–6.4 | 1.0 | |
| General | 5 | 0.3 | 3.9 | 2.1–7.2 | 1.0 | 0.5–1.8 |
| Statistical analysis | ||||||
| Crude/hand‐calculated | 8 | 0.3 | 4.3 | 2.9–6.5 | 1.0 | |
| Adjusted | 6 | 0.6 | 3.9 | 2.2–7.0 | 0.9 | 0.4–1.7 |
a
Random effects relative risks (RRs), 95% confidence limits (95% CIs).
b
Normal patients, population‐based controls, mortality rates, incidence rates.