Ways to assess the performance of methods used to estimate the prevalence of inadequacy should be investigated. Both the probability approach and the cut-point method assume that intakes and requirements are not correlated or exhibit only low correlation. In addition, the cut-point method requires that the distribution of requirements in the population is approximately symmetrical and that the variability of intakes is larger than the variability of requirements. The results presented in Appendix D (that assess the performance of the EAR cut-point method for estimating the prevalence of inadequate intakes) are from simulation studies that should be considered preliminary. A detailed investigation of the effect of violating these assumptions was beyond the scope of this report, but is a high research priority. This investigation would best be done using well-designed, well-planned, and well-implemented simulation studies. This type of study would permit recommendations to be made regarding the best approach for assessing each nutrient and would provide an estimate of the expected bias in prevalence estimates when the conditions for application of the cut-point method are not ideal.
Many of the statistical approaches suggested in this report for adjusting intake distributions and estimating the prevalence of inadequacy for groups can only be implemented with the aid of computer software. Although initial efforts have been made to develop these types of programs, a wider variety of software that can assist users of the Dietary Reference Intakes (DRIs) in correctly applying the methods recommended in this report is needed. There is also a need to upgrade the software used in dietary assessment to incorporate the appropriate statistical methodology described in this report.