Nonparametric Evaluations of Familial Aggregation

✍ Scribed by Dr. R. Chakraborty

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 653 KB
• Volume: 30
• Category: Article
• ISSN: 0323-3847
• DOI: 10.1002/bimj.4710300413

✦ Synopsis

Limitations of detection of familial aggregation, examined by nonparametric aggregate measures (e.g., SMR), or by parametric methods (e.g., segregation analysis) may involve: (1) heterogeneity of risk patterns in different kindreds, or (2) restricted choice of parametric models. Nonparametric approaches dealing with individual kindreds, on the contrary, involve sparce data for which large sample theory may not apply. Wben the expected risk schedules of individuals 8R3 known, some optimal test procedures may be developed. Nevertheless, the optimality criteria 8I-0 shown to be satisfied for only restricted choice of alternatives, end large sample approximation are not warranted in analysis of individual kindreds. Truncations of points of entry and exit of individuals in the study are needed to avoid complications due to loss of followup, in presence of which expected risk calculations are not reliable.

Covarianm of components of a goodness-of-fit test criterion detect specific modes of aggregation. It is i~~ustrated that this teat statistic is not always less powerful than the aggregate meanures in detecting aggregation, and the covariancea of its components partitioned by relative classes are in ' conformity with the results of segregation analysis.