refer to nishiura's figures and interpretation

episodes/severity-static.Rmd

@@ -299,9 +299,9 @@ We just found that the difference between the _naive_ and _delay-adjusted_ CFR e
 
 The main benefit of using `cfr_static()` is to reduce the time to get an _delay-adjusted CFR_ estimate closer to the overall CFR of the epidemic. 
 
-`cfr_static()` can assess the virulence of an emerging infectious disease at an epidemic's **early stage**. This is particularly useful when an _epidemic curve of confirmed cases_ is the only data available (i.e. when individual data from onset to death are unavailable, especially during the early stage of the epidemic).
+`cfr_static()` can assess the virulence of an emerging infectious disease at an epidemic's **early stage**. This is particularly useful when an _epidemic curve of confirmed cases_ is the only data available (i.e. when individual data from onset to death are unavailable, especially during the early stage of the epidemic). Nishiura et al., 2009 depict this in the figures below.
 
-In the figure below, Figures A and B show the cumulative numbers of cases and deaths of SARS, and Figure C shows the observed (biased) CFR estimates as a function of time, i.e. the ratio of the cumulative number of cases to deaths at time $t$. Due to the delay from the onset of symptoms to death, the biased estimate of CFR at time $t$ underestimates the realised CFR at the end of an outbreak (i.e. 302/1755 = 17.2 %). 
+Figures A and B show the cumulative numbers of cases and deaths of SARS, and Figure C shows the observed (biased) CFR estimates as a function of time, i.e. the ratio of the cumulative number of cases to deaths at time $t$. Due to the delay from the onset of symptoms to death, the biased estimate of CFR at time $t$ underestimates the realised CFR at the end of an outbreak (i.e. 302/1755 = 17.2 %). 
 
 ![Observed (biased) confirmed case fatality ratio of severe acute respiratory syndrome (SARS) in Hong Kong, 2003.](fig/cfr-pone.0006852.g003-fig_abc.png)