Figure 3

Trace plots of logit of proportion of current or former smokers among exposed to carbon black (= xsm_exp) and logit of proportion of previously exposed to crystalline silica among exposed to carbon black (= xpq_exp). Names (xsm_exp, xpq_exp) correspond to the variable names used in the R program (see Additional File 3). Results from an MCMC random walk of length 1,000,000 (Metropolis sampler) in Analysis 4 (expert's assessment, case-control smoking data). Plots include the burn-in phase of 50,000 cycles to give a complete graphical impression of the convergence behaviour of the Markov chain (Time measures 1,050,000 cycles).