Small area random effects models for capture/recapture methods with applications to estimating coverage error in the U.S. Decennial Census.

The synthetic estimation approach currently in use for estimating net coverage error in the U.S. Census is evaluated using random effects models. The synthetic estimates from the 2000 Accuracy and Coverage Evaluation (ACE) Revision II are evaluated in two parts. First, a model is used, which produces the synthetic estimate components and, second, the model is enlarged to include random effects at the small area level. Retaining all the fixed effects that characterize the synthetic model produces an extremely large, saturated random effects model. Hence, we selectively reduce the random effects model with an aim towards keeping all fixed effects in order to fairly evaluate the synthetic model. A super-population model is used for the bivariate outcome of erroneous enumeration rate and census omission rate. Both these outcomes were previously estimated using the current synthetic estimation approach. A major hurdle in this project was the development of defensible input data for the small areas due to the large number of effects in the synthetic model, which render simple design-based estimates for small areas crossed with post-strata, mostly, unusable. For this initial approach, the small areas were the 540 local census offices. Bayesian methods are employed to evaluate these models. The advantage of this model is that it can evaluate a key assumption about the homogeneity of rates within a post-stratum and if the assumption holds, then this model reduces to the current synthetic model.

Examining clinical judgment in an adaptive intervention design: The fast track program.

Although clinical judgment is often used in assessment and treatment planning, rarely has research examined its reliability, validity, or impact in practice settings. This study tailored the frequency of home visits in a prevention program for aggressive- disruptive children (n = 410; 56% minority) on the basis of 2 kinds of clinical judgment: ratings of parental functioning using a standardized multi-item scale and global assessments of family need for services. Stronger reliability and better concurrent and predictive validity emerged for the 1st kind of clinical judgment than for the 2nd. Exploratory analyses suggested that using ratings of parental functioning to tailor treatment recommendations improved the impact of the intervention by the end of 3rd grade but using more global assessments of family need did not.

Decoupling the relation between risk factors for conduct problems and the receipt of intervention services: participation across multiple components of a prevention program.

This study examined whether the link between risk factors for conduct problems and low rates of participation in mental health treatment could be decoupled through the provision of integrated prevention services in multiple easily-accessible contexts. It included 445 families of first-grade children (55% minority), living in four diverse communities, and selected for early signs of conduct problems. Results indicated that, under the right circumstances, these children and families could be enticed to participate at high rates in school-based services, therapeutic groups, and home visits. Because different sets of risk factors were related to different profiles of participation across the components of the prevention program, findings highlight the need to offer services in multiple contexts to reach all children and families who might benefit from them.

Two-level proportional hazards models.

We extend the proportional hazards model to a two-level model with a random intercept term and random coefficients. The parameters in the multilevel model are estimated by a combination of EM and Newton-Raphson algorithms. Even for samples of 50 groups, this method produces estimators of the fixed effects coefficients that are approximately unbiased and normally distributed. Two different methods, observed information and profile likelihood information, will be used to estimate the standard errors. This work is motivated by the goal of understanding the determinants of contraceptive use among Nepalese women in the Chitwan Valley Family Study (Axinn, Barber, and Ghimire, 1997). We utilize a two-level hazard model to examine how education and access to education for children covary with the initiation of permanent contraceptive use.