Disparity in disease, equality in death? Socioeconomic disparities in life expectancy after disease onset: a full-population cohort study over 64 non-communicable diseases in Denmark 2013-2022.

Individual socioeconomic position is known to affect the progression of disease and mortality after disease onset. Existing studies generally focus on single diseases, making it unclear whether this is a universal pattern or a common characteristic across disease classes. The objective of this study is to examine educational and income inequalities in life expectancy after diagnosis of noncommunicable diseases. Based on full population Danish registers (N = 4 420 226), we created multistate models for 64 noncommunicable diseases according to education, income, age and sex. Transition probabilities from healthy to sick and deceased were estimated with a multinomial logit model and used for the construction of life tables from which we estimated life expectancy after diagnosis. We observed education and income inequalities in life expectancy after diagnosis across all noncommunicable diseases studied for both men and women. For example, a woman diagnosed with cirrhosis of the liver at age 50, has a life expectancy of almost 17 years if she has a high education and 14 years if she has a low education. For men, life expectancy after diagnosis of cirrhosis is 13 years for the high educated and 10 years for the low educated. Our findings show that socioeconomic inequalities in life expectancy after disease onset are consistent across a wide range of noncommunicable diseases. In terms of policy, our study highlights the need for interventions that reduce the accumulation of risk before individuals become patients, and strengthen the healthcare system's ability to mitigate inequalities.