Health equity: Utopian and scientific

摘要

They say that the road to hell is paved with good intentions, and nobody has better intentions than we do in public health. Let others blather on about evidence while we spend our time removing pump handles. And so it was that the well intentioned public health leaders in Hamburg, Germany faced a cholera epidemic in 1892 and sprang to action. They dutifully exhumed all of the carcasses underneath slaughterhouses, in accordance with Max von Pettenkofer's miasma theory, and carted them away. Sadly for them, this intervention was wholly misguided, and nearly nine thousand people died (Evans, 1987). In fact, Snow had published his work on the transmission of cholera through fecally contaminated water decades earlier. Cholera was associated with a great many things, including poverty and crowding, and so on the basis of these patterns, the miasma theory seemed perfectly reasonable. But Snow's innovation, for which he is considered to be the father of modern scientific thinking in our field, was to rely not on these observed associations, but instead on a natural experiment in which houses were "randomly" assigned a contaminated or an uncon-taminated water supply. Only on the basis of this quasi-experimental evidence was Snow confident of what public health action needed to be taken (Freedman, 1999).