Compression or expansion of morbidity: evaluating life expectancy with and without cardiovascular diseases in Denmark

Background: Cardiovascular diseases (CVDs) are among the leading causes of death in high-income countries and represent a major source of morbidity across the life course. Understanding how the time spent with CVD has evolved over time and how it differs between men and women requires going beyond summary measures of health expectancy, which condense complex health trajectories into a single number. Methods: Using Danish population registers from 2005 to 2018, we employ novel bivariate age-at-death distributions to examine how the experience of cardiovascular morbidity is distributed across the population, how it has changed over time and how it differs between sexes. Results: Our findings point towards an expansion of CVD morbidity, with individuals who experienced a CVD hospitalisation spending an increasing number of years with the condition prior to death. This occurs alongside a decline in CVD incidence, as a growing proportion of individuals reach advanced ages without ever being hospitalised for a cardiovascular condition. Women are more likely than men to die without ever experiencing a CVD hospitalisation, and spend fewer years with the condition before death. Conclusions: The coexistence of expanding morbidity and declining incidence reflects progress on both prevention and treatment fronts, and need not be interpreted as a sign of worsening population health. The bivariate framework and visualisations introduced offer a valuable complement to existing health indicators, capturing the full distribution of morbidity experiences that summary measures conceal.