Showing papers by "Frank B. Hu published in 1996"
TL;DR: The authors calculated intraclass correlations for some common outcome variables in a school-based smoking prevention study, using a three-level model-i.e., students nested within classrooms and classrooms nested within schools.
Abstract: Most school-based smoking prevention studies employ designs in which schools or classrooms are assigned to different treatment conditions while observations are made on individual students. This design requires that the treatment effect be assessed against the between-school variance. However, the between-school variance is usually larger than the variance that would be obtained if students were individually randomized to different conditions. Consequently, the power of the test for a treatment effect is reduced, and it becomes difficult to detect important treatment effects. To assess the potential loss of power or to calculate appropriate sample sizes, investigators need good estimates of the intraclass correlations for the variables of interest. The authors calculated intraclass correlations for some common outcome variables in a school-based smoking prevention study, using a three-level model-i.e., students nested within classrooms and classrooms nested within schools. The authors present the intraclass correlation estimates for the entire data set, as well as separately by sex and ethnicity. They also illustrate the use of these estimates in the planning of future studies.
157 citations
TL;DR: By considering the characteristics of dropouts, one can reduce attrition bias using available procedures and can take appropriate strategies for reducing dropout rates in future smoking prevention studies.
129 citations
TL;DR: A problem-prone behavior perspective of ST use and cigarette smoking is supported and it is suggested that both products be targeted because the same programs are likely to apply to both products to counteract problem- prone type variables.
19 citations
TL;DR: Protein produced in time studies was shown by immunoblotting and sandwich EIA to bind human IgE from Alternaria sensitive patients and therefore should be useful as a model for studying allergy to the native Alternaria glycoprotein.
Abstract: Allergen content of extract derived from Alternaria is somewhat variable. Allergenic molecules from Alternaria that appear as differing molecular size bands on IgE probed immunoblots may have a great deal of sequence homology and differ only in the length of the amino acid chain. One method to study this problem is to produce recombinant proteins from Alternaria. To explore these possibilities, the following experiments were performed.
14 citations