Context: Several studies have searched for factors that significantly influence adult height (AH) of children with growth hormone deficiency (GHD) who have been treated with biosynthetic GH, but a prediction model for AH has not yet been presented.

Objective: To develop models for prediction of AH, using information available at start of GH treatment or after one year of treatment.

Design: Retrospective study.

Setting: Data were collected from the National Registry of Growth Hormone Treatment in Children, which contained data of Dutch children treated with GH.

Patients / Intervention: Males born prior to 1985, females prior to 1987, with either diagnosis of GHD (excluded: syndromes, tumours, other diseases) or maximum GH response during provocation tests < 11 ng/ml, treated with biosynthetic GH for at least one year. To be able to use the complete group of 342 children for the development of the models, multiple imputation was used for missing values.

Main Outcome Measure: Adult height SDS.

Results: Each prediction model contained both target height SDS and current height SDS. The change in height SDS during the first year proved an important predictor for AH. In all models addition of GH dose was not significant. The percentage explained variance, after correction for overfitting, ranged from 37% (prepubertal children, prediction at start) to 60% (pubertal children, prediction after one year).

Conclusion: The presented prediction models give accurate predictions of AH for children with GHD at start and after one year of GH treatment. They are useful tools in the treatment of these children.