This project addresses statistical problems generated from collaboration with scientists in other program areas and general statistical problems of current interest. This project is a continuing activity of the Section on Mathematical Statistics. Papers have been submitted, are in review or were published in FY 1990 on the following statistical subjects: estimation of the joint survival and censoring distribution in the presence of dependent censoring; statistical planning, design and analysis of randomized clinical trials in neurology; development of a Weibull model for survival data with dependent censoring; an empirical Bayes procedure for examining the relationships between multiple time series; establishing statistical quality control methods for biomedical laboratories; design of panel studies under alternating Poisson process assumptions. Other work in progress includes: selection criteria for use of the Kaplan-Meier or parametric MLE for survival analysis; influence of missing data in randomized clinical trials; methods to improve coverage in surveys; analysis of time-to-event data with non-regular censoring; estimation of time-to-event with interval data in the presence of left and right censoring; site selection for epidemiological surveys; adjustments or covariates in the analysis of categorical data; two-state models for analyzing time series count data; analysis of response surface data with both spatial and temporal components; development of sampling strategies for count data in the presence of multiple types of clustering; estimation of hazard functions with time-dependent covariates in the presence of competing risks.
