A value of information framework for assessing the trade-offs associated with uncertainty,duration, and cost of chemical toxicity testing

A number of investigators have explored the use of value of information (VOI) analysis to evaluate alternative information collection procedures in diverse decision-making contexts. This paper presents an analytic framework for determining the value of toxicity information used in risk-based decision making. The framework is specifically designed to explore the trade-offs between cost, timeliness, and uncertainty reduction associated with different toxicity-testing methodologies. The use of the proposed framework is demonstrated by two illustrative applications which, although based on simplified assumptions, show the insights that can be obtained through the use of VOI analysis. Specifically, these results suggest that timeliness of information collection has a significant impact on estimates of the VOI of chemical toxicity tests, even in the presence of smaller reductions in uncertainty. The framework introduces the concept of the expected value of delayed sample information, as an extension to the usual expected value of sample information, to accommodate the reductions in value resulting from delayed decision making. Our analysis also suggests that lower cost and higher throughput testing also may be beneficial in terms of public health benefits by increasing the number of substances that can be evaluated within a given budget. When the relative value is expressed in terms of return-on-investment per testing strategy, the differences can be substantial.     

Social Contagion and General Diffusion Models of Adolescent Religious Transitions: A Tutorial,and EMOSA Applications

Epidemic Models of the Onset of Social Activities (EMOSA) describe behaviors that spread through social networks. Two social influence methods are represented, social contagion (one-to-one spread) and general diffusion (spread through cultural channels). Past models explain problem behaviors—smoking, drinking, sexuality, and delinquency. We provide review, and a tutorial (including examples). Following, we present new EMOSA models explaining changes in adolescent and young adult religious participation. We fit the model to 10 years of data from the 1997 U.S. National Longitudinal Survey of Youth. Innovations include a three-stage bi-directional model, Bayesian Markov Chain Monte Carlo (MCMC) estimation, graphical innovations, and empirical validation. General diffusion dominated rapid reduction in church attendance during adolescence; both diffusion and social contagion explained church attendance stability in early adulthood.     

Long-Term RCT outcomes for adolescent alcohol and cannabis use within a predominantly Hispanic sample

Because adolescents are unlikely to seek, receive, or complete treatment for alcohol and/or cannabis misuse, it is important to enhance the lasting impact of clinical contacts when they do occur. Adolescents (N = 506; 72.5% Hispanic) were randomized to motivational interviewing (MI) versus alcohol and cannabis education (ACE). Latent growth models estimated change over time. Significant reductions in alcohol use were observed, with slightly greater reductions by 12-month follow-up for MI. Both interventions significantly reduced cannabis use, with no treatment group differences. When outcomes were examined comparing Hispanic to non-Hispanic participants, there were no significant differences in intervention efficacy by group. MI's inherently client-centered and culturally adaptive approach may contribute to its equitable degree of behavior change for youth across race/ethnic backgrounds.