Another analysis was conducted for ever vs never breastfed, including 14 studies because 3 studies did not have
data for never breastfed.18, 41,43 The definition of never breastfed differed among studies, with some defining never as no and some as
less than 1 month; therefore, between - study
heterogeneity was significantly higher (Cochran - Q = 38; P <.01; I2 = 65.8 %; 95 % CI, 30.8 % -79.2 %).