Comparison of different indices of dietary control in phenylketonuria

Acta Paediatr. 1995 May;84(5):521-7. doi: 10.1111/j.1651-2227.1995.tb13686.x.


Ten different indices of dietary control (IDCs) applied frequently to investigate compliance of phenylketonuric patients were calculated for a set of blood phenylalanine levels for 98 patients in the German Collaborative Study of Children Treated for Phenylketonuria during their first 9 years of life. The results were compared for similarities and differences. Cluster analysis of longitudinal phenylalanine data was introduced to analyse phenylalanine blood levels independent of a priori defined criteria of classification. Three groups of good, intermediate and poor long-term dietary control were identified. Internal validation of the IDCs was corroborated by the high inter-correlations of the indices. External validity was determined by the inter-relations of the WISC-R IQ and the IDCs. The different algorithms of IDCs suggest different clinical conclusions. To facilitate comparisons of results of future research, IDCs should be standardized.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Cluster Analysis
  • Female
  • Humans
  • Male
  • Nutrition Assessment*
  • Phenylalanine / blood*
  • Phenylketonurias / blood*
  • Phenylketonurias / diet therapy*
  • Reproducibility of Results


  • Phenylalanine