Fig1.

Forest plots from the meta-analyses of case control (CC, interview-based) and nested case-control (NCC, registry-based, record-linkage) studies on the association of (A) paternal and (B) maternal age (5-year increments) with childhood (0–14 years) acute lymphoblastic leukemia.

Random-effect meta-analysis of maximally adjusted Odds Ratios from individual studies for any of the following variables that were available (<20% missing values in the total dataset): index child’s age (categorical; <1, 1–4 [reference], 5–9, 10–14 years), sex, ethnicity (Caucasian vs. non-Caucasian), birth weight (continuous; 500 gr increment), maternal education (categorical; low, intermediate [reference], high) pre-term birth (yes vs. no), maternal smoking during pregnancy (yes vs. no), multiple pregnancy (yes vs. no) and birth order (continuous; 1, 2, ≥3). Studies are presented in ascending order according to the mean maternal and paternal age. Maternal and paternal age are simultaneously introduced in all models.