Detecting the "Big Red Spot" of age-period excess mortality in 25 countries: Age-period-cohort residual analysis

In times of wide availability of yearly mortality information of age and period groups all over the
world, we lack in tools that detect and graph fine-grained deviations from mortality trends. We
provide a new age-period-cohort based methodology, combining information from age-period
(AP) and APC-Detrended (APCD) analyses to detect all-cause mortality increases. Plotting the
resulting AP coefficients and APCD residuals in equilateral Lexis diagrams, mortality patterns
can easily be distinguished as age, period, or cohort trends and fluctuations. Additionally, we
detect abnormalities as interactions of age and period (‘big red spots’). We then investigate the
‘red spots’ of mortality of young-adult cohorts in the early 1990s in Spain, other southern
European countries and the U.S. to delineate their simultaneously occurring public health crises.
Additional analyses with WHO mortality data show that mortality increases are mostly due to
increased HIV/AIDS mortality. We discuss possible applications of the new method.