March 19, 2019

A study of 6 million people found  a strong link between socioeconomic status (SES) and life expectancy among a population with universal healthcare. Men and women in the lowest SES group had 12 and 9 years’ lower life expectancy respectively, than those in the highest SES group of the same age.  The study also found that the lower the SES, the higher odds of death, independent of age and sex.

Led by Usama Bilal, MD, PhD, MPH, assistant professor in the Urban Health Collaborative and the Department of Epidemiology and Biostatistics at Drexel's Dornsife School of Public Health, the team studied the entire adult population of Catalonia. The team used the Catalan Health Surveillance System database, which includes individual-level information on sociodemographic characteristics and mortality for all residents of Catalonia. They categorized individuals as high, medium, low or very low SES based on annual personal income and welfare receipt.

This study has important implications. Socioeconomic status  inequalities in life expectancy and mortality may emerge from the unequal distribution of risk factors or the unequal effect of risk factors. For example, for cardiovascular disease, the most common cause of death in Spain, differential exposure involves a higher burden of risk factors such as obesity, diabetes, hypertension, or smoking in people of lower SES. Differential susceptibility would entail a stronger effect of these risk factors on mortality in people of lower SES, which could be due to differential use of healthcare resources.

The research was published in Preventive Medicine.