Table 2 Summary statistics for the association between consumption of pickled vegetables and oesophageal cancer

From: Pickled vegetables and the risk of oesophageal cancer: a meta-analysis

  Number of studies Q -statistic a P -value b I2 (%)c Random effects OR (95% CI)
All studies 34 282.18 <0.001 88 2.08 (1.66–2.60)
After excluding the three most influential studies 31 120.45 <0.001 75 2.32 (1.92–2.81)
Prospective studies 3 10.26 0.006 81 1.52 (0.82–1.63)
Case-control studies 31 179.25 <0.001 83 2.18 (1.75–2.73)
Large studies (standard error 0.5) 30 259.42 <0.001 89 2.09 (1.67–2.63)
Studies with population-based controls 18 185.63 <0.001 91 2.11 (1.56–2.85)
Studies with age-matched controls 27 171.69 <0.001 85 2.14 (1.66–2.76)
Adjusted results 24 196.16 <0.001 88 2.15 (1.64–2.81)
Studies reporting consumption rates among cases and controls 18 57.61 <0.001 70 2.55 (2.01–3.24)
Studies from Linxian, China 4 18.69 <0.001 84 1.51 (0.98–2.33)
Studies not from Linxian, China 30 220.89 <0.001 87 2.17 (1.70–2.78)
Studies initiated in 1990 or earlierd 13 160.43 <0.001 93 1.73 (1.14–2.62)
Studies initiated after 1990d 20 51.69 0.002 63 2.28 (1.89–2.76)
Studies from China (Mainland) 29 246.64 <0.001 89 2.10 (1.63–2.69)
Studies not from China (Mainland) 5 25.31 <0.001 84 1.96 (1.12–3.43)
Studies published in English literature 15 198.34 <0.001 93 2.10 (1.47–3.00)
Studies published in Chinese literature 19 60.06 <0.001 70 2.10 (1.65–2.67)
  1. Abbreviations: CI=confidence interval; OR=odds ratio.
  2. aChi-square Q-statistic for homogeneity.
  3. bP-value for the Q-statistic.
  4. cHiggins I2 statistic for heterogeneity.
  5. dOne study was excluded from these analyses because the starting year was not reported.