Presenteeism
==============
Presenteeism was calculated as a function of absenteeism. In general, research on presenteeism is 
scarce, and represents less than one percent of all productivity-related research, based on a 
published review :cite:p:`Zhang2011`. A similar, non-published review by the 
World Health Organization has only identified three presenteeism studies of sufficiently high quality 
to quantify obesity-condition related absenteeism. Further, most evidence comes from the 
United Kingdom and the United States, where sick leave is much less predominant than in EU countries.

As a result of the scarce evidence, a ratio of condition-specific presenteeism:absenteeism rates from a 
high quality productivity study was calculated and applied to the econometric absenteeism results 
:cite:p:`Goetzel2004`. For example, if diabetes led 
to missing seven annual work days in country X, then 7*1.8 days of presenteeism would have been observed 
in this country.

.. _ehis_abstenteeism:
.. figure:: files/Absenteeism_ratio.png
   :alt: ratio.png 
   :width: 450px
   :align: center
   :figclass: align-center

   Absenteeism and presenteeism ratio for select chronic conditions 

Source: :cite:p:`Goetzel2004`