The differences in the prevalence of NE between co-sleepers and non-co-sleepers were significant in the 9-year age group ( OR , 1.49 ; 95 % CI , 1.06-2 .11 ; p = .025 ) and 11 - to 12-year age group ( OR , 3.16 ; 95 % CI , 2.19-4 .57 ; p < .001 ) .