BackgroundThe first-year growth in response to growth hormone (GH) treatment seems to be the most important factor in determining the overall success of GH treatment.MethodsData from children (n = 345) who were in the LG Growth Study Database were used to develop a model. All subjects had been diagnosed with idiopathic growth hormone deficiency (GHD) and presented in a prepubertal state during the first year of GH treatment.ResultsThe Δheight standard deviation score (SDS) during 1st year of GH treatment was correlated positively with weight-SDS (β = 0.304, P < 0.001), body mass index (BMI)-SDS (β = 0.443, P < 0.001), paternal height-SDS (β = 0.296, P = 0.001), MPH-SDS (β = 0.421, P < 0.001) and MPH SDS minus baseline height SDS (β = 0.099, P < 0.001) but negatively with chronological age (β = −0.294, P < 0.001), bone age (β = −0.249, P < 0.001). A prediction model of 1st year growth in response to GH treatment in prepubertal Korean children with idiopathic GHD is as follows: Δheight SDS during 1st year of GH treatment = 1.06 − 0.05 × age + 0.09 × (MPH SDS minus baseline height SDS) + 0.05 × BMI SDS. This model explained 19.6% of the variability in the response, with a standard error of 0.31.ConclusionThe present model to predict first-year response to GH treatment might allow more tailored and personalized GH treatment in Korean prepubertal children with idiopathic GHD.Trial RegistrationClinicalTrials.gov Identifier: NCT01604395