Table 3

Risk of the primary long-term outcomes by exposure group

Outcome*Unadjusted HR (95% CI)†IPTW-weighted HR (95% CI)‡
Metformin versus insulinCombination treatment versus insulinMetformin versus insulinCombination treatment versus insulin
Obesity1.15
(0.82 to 1.60)		1.35
(1.02 to 1.78)		1.14
(0.83 to 1.55)		1.09
(0.76 to 1.58)
Hypoglycemia0.80
(0.49 to 1.30)		1.11
(0.65 to 1.89)		1.00
(0.61 to 1.64)		1.14
(0.71 to 1.83)
Hyperglycemia1.00
(0.61 to 1.64)		0.42
(0.14 to 1.25)		1.23
(0.63 to 2.42)		0.22
(0.05 to 1.01)
Diabetes mellitus1.32
(0.65 to 2.67)		0.70
(0.09 to 5.21)		1.19
(0.51 to 2.82)		0.14
(0.02 to 1.15)
Challenges in motor–social development1.25
(1.11 to 1.40)		1.58
(1.26 to 1.98)		1.09
(0.93 to 1.27)		1.11
(0.77 to 1.59)

  • *No events of the long-term primary outcomes hypertension and PCOS were observed in the metformin or combination treatment groups.

  • †Metformin and combination treatment were compared with insulin. In the unadjusted comparison, 3967 children were exposed to metformin; 889 children were exposed to combination treatment; and 5273 were exposed to insulin.

  • ‡Metformin and combination treatment were analyzed separately, in pairwise comparisons with insulin (reference in all analyses). Analyses were conducted in the main cohort after trimming of children outside the overlapping range of the propensity score. In the IPTW analyses of metformin versus insulin, 3671 children exposed to metformin and 5218 exposed to insulin included; in the analyses of combination treatment versus insulin, 882 children exposed to combination treatment and 5252 exposed to insulin included.

  • IPTW, inverse probability of treatment weighting; PCOS, polycystic ovary syndrome.