Table 2

Level of aerobic versus anti-anaerobic antibiotic use and risk of colorectal cancer

AuthorOutcomeLevel of exposureAnti-anaerobic agents,
ES (95% CI)
Anti-aerobic agents,
ES (95% CI)
Zhang28Colon0 daysReferenceReference
Zhang28Colon1–15 days1.07 (1.03 to 1.12)1.00 (0.96 to 1.05)
Zhang28Colon16–30 days1.10 (1.04 to 1.16)1.11 (1.03 to 1.20)
Zhang28Colon31–60 days1.12 (1.06 to 1.19)1.00 (0.90 to 1.12)
Zhang28Colon>60 days1.14 (1.07 to 1.21)0.97 (0.86 to 1.10)
Zhang28Rectal0 daysReferenceReference
Zhang28Rectal1–15 days1.01 (0.95 to 1.07)0.96 (0.90 to 1.03)
Zhang28Rectal16–30 days0.96 (0.89 to 1.04)0.92 (0.81 to 1.05)
Zhang28Rectal31–60 days0.97 (0.89 to 1.06)0.84 (0.70 to 1.01)
Zhang28Rectal>60 days0.88 (0.80 to 0.97)0.84 (0.68 to 1.03)
Wang27ColonNo useReferenceReference
Wang27ColonAny use2.31 (2.12 to 2.52)0.94 (0.79 to 1.12)
Wang27ColonLowest tertile of number of prescriptions3.77 (3.39 to 4.20)0.90 (0.75 to 1.08)
Wang27ColonSecond tertile of number of prescriptions1.90 (1.67 to 2.16)0.99 (0.82 to 1.20)
Wang27ColonHighest tertile of number of prescriptions1.27 (1.10 to 1.46)0.77 (0.63 to 0.94)
Wang27RectalNo useReferenceReference
Wang27RectalAny use1.69 (1.50 to 1.90)0.93 (0.76 to 1.14)
Wang27RectalLowest tertile of number of prescriptions2.47 (2.13 to 2.86)0.88 (0.71 to 1.09)
Wang27RectalSecond tertile of number of prescriptions1.35 (1.13 to 1.62)0.99 (0.80 to 1.23)
Wang27RectalHighest tertile of number of prescriptions1.10 (0.91 to 1.35)0.82 (0.65 to 1.05)
Dik29CRCNo useReferenceReference
Dik29CRC1–2 prescriptions1.12 (1.03 to 1.23)1.08 (0.99 to 1.18)
Dik29CRC3–4 prescriptions1.27 (1.02 to 1.58)1.01 (0.90 to 1.13)
Dik29CRC5–7 prescriptionsn/a1.09 (0.95 to 1.25)
Dik29CRC8 or more prescriptionsn/a1.25 (1.08 to 1.45)
Dik29CRC5 or more prescriptions1.45 (1.07 to 1.97)n/a
  • CRC, colorectal cancer; ES, effect size; n/a, not available.