Table 3 Summary of evidence grading for meta-analyses associating coffee intake with cancer incidence Level of evidence
From: Coffee drinking and cancer risk: an umbrella review of meta-analyses of observational studies
| Criteria used | Decreased risk | Increased risk | |
|---|---|---|---|
| Strong | P in random-effects model < = 0.001 Number of cases > 1000 I2 < = 50% 95% predictive intervals exclude the null value Small study effects P > 0.1 Excess significance bias P > 0.1 | None | Acute lymphocytic leukemia (H/L) |
| Highly suggestive | P in random-effects model < = 0.001Number of cases > 1000 I2 < = 75% | Endometrial cancer (H/L); Endometrial cancer (Per 1 cup); Liver cancer (H/L); Liver cancer (Per 1 cup); Melanoma (H/L); Oral cancer (H/L); Oral/pharyngeal cancer (H/L) | Bladder (H/L) |
| Suggestive | P in random-effects model < = 0.001Number of cases > 500 | None | Lung cancer (H/L) |
| Weak | P in random-effects model <= 0.05 | Breast cancer (Per 1 cup); Colon cancer (Per 1 cup); Colorectal cancer (H/L); Esophageal cancer (H/L); Nonmelanoma (H/L) | Leukemia (H/L); Lung (Per 1 cup) |
| No association | P in random-effects model > 0.05 | Pancreatic cancer (H/L); Breast cancer (H/L); Colon cancer (H/L); Ovarian cancer (H/L); Acute myelogenous leukemia (H/L); Pancreatic cancer (Per 1 cup); Rectal cancer (Per 1 cup); Kidney cancer (H/L); Laryngeal cancer (H/L); Rectal cancer (H/L); Colorectal cancer (Per 1 cup); Thyroid cancer (H/L); Prostate cancer (H/L); Gastric cancer (Per 1 cup); Gastric cancer (H/L); Lymphoma (H/L); Glioma (Per 1 cup); Glioma (H/L); Biliary tract cancer (H/L). | |