30

Figure 2.4: Estimated mixture of normal distribution of the latent variable ι⅛∙ con-
ditioned on τi — 0 for j = 1,..., 7. Shaded curve corresponds to placebo (x = — 1)
and dashed to isotretinoin (τ = 1). Darkly and lightly shaded areas represent, re-
spectively, the probability of no toxicity (πj∙0) and toxicity at grade 1 (π7∙1) under
placebo.
2.7 Discussion
We have proposed a Bayesian hierarchical model to analyze ordinal data nested within
categories. Our model characterizes the ordinal∕categorical data structure by a varia-
tion of the ordinal probit model. We provide posterior summaries to assess treatment
effects. In the phase III clinical trial example, traditional analysis might simply group
the toxicities levels into two: no toxicity (0) and some toxicity (1+2+3+4), and then,
apply a Chi-squared test or Fisher’s exact test to compare the two treatment groups
More intriguing information
1. Population ageing, taxation, pensions and health costs, CHERE Working Paper 2007/102. Julkinen T&K-rahoitus ja sen vaikutus yrityksiin - Analyysi metalli- ja elektroniikkateollisuudesta
3. Wirkt eine Preisregulierung nur auf den Preis?: Anmerkungen zu den Wirkungen einer Preisregulierung auf das Werbevolumen
4. The demand for urban transport: An application of discrete choice model for Cadiz
5. Legal Minimum Wages and the Wages of Formal and Informal Sector Workers in Costa Rica
6. The name is absent
7. The name is absent
8. The name is absent
9. PRIORITIES IN THE CHANGING WORLD OF AGRICULTURE
10. AN ANALYTICAL METHOD TO CALCULATE THE ERGODIC AND DIFFERENCE MATRICES OF THE DISCOUNTED MARKOV DECISION PROCESSES