Background During the early 19th century, contagionists' and anti-contagionists' explanations of disease causes opposed one another, and the Hippocratic miasma theory still predominated. According to that theory, geographic health disparities could be explained by topographical factors: differences in altitude, population density or proximity to a river. This article summarizes the life of Louis-René Villermé (1782–1863) and his major contributions to social epidemiology that proved the association between poverty and mortality.

Methods In this study, data reported by Villermé to study the mortality-rate variations across the 12 districts (arrondissements) of Paris—that is, 1817–1826 Parisian death rates by district, population density and income indicators—are presented and reanalyzed.

Results Results obtained with today's statistical techniques (correlation analysis) support Villermé's claims of a direct poverty–high death rate link: the three income indicators that he chose were significantly correlated with at-home mortality: taxation index (r=–0.83, p<0.002), average rent (r=–0.83, p<0.002), trade taxation index (r=–0.67, p<0.05), while population density variables were not associated with mortality.

Conclusion Villermé was not only a forerunner of social epidemiology, he was also a scientific pioneer by relying on data, not opinions, to challenge or support medical hypotheses.