Table 1

Characteristics of cases and controls and univariate associations between risk factors and medicinal poisoning

CharacteristicCases (%), n = 1316Controls (%), n = 12 836Unadjusted odds ratio (95% CI)
Child characteristics
Sex of child
 Female627 (48)6284 (49)1.00
 Male689 (52)6552 (51)1.05 (0.94 to 1.18)
Age when poisoning occurred, months
 0–12108 (8)4272 (33)1.00
 13–24430 (33)2799 (22)6.22 (5.01 to 7.74)
 25–36516 (39)2308 (18)9.24 (7.44 to 11.47)
 ≥37262 (20)3457 (27)3.15 (2.49 to 3.97)
Birth order of child
 1st853 (65)9093 (71)1.00
 2nd390 (30)3192 (25)1.34 (1.17 to 1.53)
 3rd or more73 (5)551 (4)1.48 (1.14 to 1.92
Maternal characteristics
Maternal age at birth of child, years
 <20111 (8)733 (6)1.00
 20–29724 (55)6308 (49)0.75 (0.60 to 0.93)
 30–39448 (34)5481 (43)0.53 (0.42 to 0.66)
 ≥4033 (3)314 (2)0.67 (0.44 to 1.02)
Maternal diagnosis of depression
 No1177 (89)11 938 (93)1.00
 Yes139 (11)898 (7)1.58 (1.31 to 1.92)
Maternal smoking
 Never smoked586 (44)6414 (50)1.00
 Ex-smoker63 (5)556 (4)1.26 (0.95 to 1.66)
 Current smoker343 (26)2809 (22)1.35 (1.17 to 1.56)
 Missing324 (25)3057 (24)1.17 (0.99 to 1.37)
Maternal alcohol misuse
 Never1299 (98.71)12 774 (99.52)1.00
 ≤1 year before poisoning7 (0.53)12 (0.09)5.54 (2.17 to 14.15)
 >1 year before poisoning10 (0.76)50 (0.39)1.99 (1.00 to 3.93)
Social characteristics
Townsend index quintile
 1 (least deprived)260 (20)2843 (22)1.00
 2200 (15)2370 (18)0.93 (0.76 to 1.13)
 3252 (19)2439 (19)1.17 (0.96 to 1.41)
 4266 (20)2300 (18)1.35 (1.12 to 1.65)
 5 (most deprived)242 (19)1876 (15)1.57 (1.28 to 1.93)
 Missing96 (7)1008 (8)0.94 (0.63 to 1.39)
Single parenthood
 Single adult581 (44)4906 (38)1.00
 Two adults646 (49)6817 (53)0.78 (0.69 to 0.89)
 Other89 (7)1113 (9)0.66 (0.52 to 0.84)