Table 1.

Parameter values for simulation studies

Simulation parameter	Values
Randomization of complete twin pairs	Same arm, independently, opposite arms
Total sample size	250, 500
Proportion of infants from complete twin pairs	0.1, 0.2
Continuous outcomes
Standardized effect size	0, 0.5, 1, 1.5
Within-birth correlation	0, 0.25, 0.5
Binary outcomes
Treatment effect, measured on log scale	-1, -0.5, 0
Log odds ratio measuring within-birth correlation	-2, -1.5, -1, -0.5