Issues involved in the phenotypic classification of orofacial clefts ascertained through a state birth defects registry for the North Carolina Cleft Outcomes Study.

Background: Epidemiologic studies involving birth defects are extremely sensitive to phenotype accuracy and precision. We devised a case review and classification protocol for a project to study school achievement in children with idiopathic, nonsyndromic orofacial clefts to improve the reliability of phenotypic classification from the statewide birth defects registry.

Methods: Surveillance-program abstraction data and medical records at the birth or treating hospitals were used when available.

The Effect of altering ADL thresholds on active life expectancy estimates for older persons.

Objectives: Research on disability and active life expectancy (ALE) has often criticized the measurement of disability but has rarely empirically investigated the effect of changing measurement. The purpose of this study was to determine whether altering the number of activities of daily living (ADLs) required to consider an individual "disabled" affects population-based ALE estimates after considering parametric uncertainty and sampling error.

Methods: The authors develop a Bayesian approach to estimating multistate life tables for a three-dimensional state space, using data on community-dwelling older adults from the 1989 and 1994 National Long Term Care Survey analytic files.