Variability in time of the relative slope of correlations of PCPI for each state with age-adjusted AD death rates (AADRs) for the respective states in 2005.

<p>The Relative slope was calculated by dividing slope data from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126139#pone.0126139.g004" target="_blank">Fig 4</a> by the coefficient of stratification of PCPI between poorest and richest states; f = PCPI highest/PCPI lowest. This procedure removes the time-dependent influence of stratification of PCPI between states. Solid line regression curve obtained as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126139#pone.0126139.g003" target="_blank">Fig 3</a>, dashed lines—95% confidence intervals. The oscillatory character of the relative slope resembles the oscillations of R in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126139#pone.0126139.g003" target="_blank">Fig 3</a>. Numbers of states as in legend to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126139#pone.0126139.g003" target="_blank">Fig 3</a>