Fig. 2

Pooled OR and 95% CI for the association between ever versus never smoking and risk of meningioma in women. Ever smoking was associated with a significantly reduced risk of meningioma in women, with pooled OR of 0.83 (95% CI 0.70–0.98, P for heterogeneity, 0.085). Considering the area, the OR of ever smoking was 0.77 (95% CI 0.68–0.87, P for heterogeneity, 0.362) in three American studies, 0.99 (95% CI 0.73–1.35, P for heterogeneity, 0.100) in four studies conducted in other countries.