Predictive value of the Merrill-Palmer-R Scale applied during the first year of live

The predictive value of a developmental scale used during the first year of life is of great interest when planning early interventions. The predictive value of an instrument is the probability of hitting the diagnosis of disorder or developmental delay of a child. The cut-off point between normal and disability development recommended by the Merrill-Palmer-R Scale (MP-R) is the mean - 1 σ, assuming a normal distribution. The MP-R scores in a sample of 291 children under one year old from the Valencian community were analysed. Even though the distribution of the MP-R scale in this sample was not normal, the forecast results were good. Additionally, the development scores using a new version of the scale were assessed using the Rasch model. Comparing the predictive value of the MP-R using two calculated cut-off points, both methods achieved good predictive values. We discuss if the cut-off point scores based on criteria should be used instead of typical scores.