An explanation of the persistent doctor-mortality association.

STUDY
OBJECTIVE: The aim of the study is to explain the persistent but puzzling positive correlation of physicians per capita and mortality rates, when income is controlled, which has been reported many times since it was first observed in 1978. The explanation that is proposed and tested is that expanding urban-industrial regions attract an oversupply of doctors. Also, but independently, rural people migrate to urban-industrial areas where they suffer from the stress of adapting to urban-industrial life. Consequently, their death rates rise. SOURCE MATERIAL: Using data from the 47 Japanese prefectures, the 3000+ counties of the USA and a set of 29 mostly European countries, the explanation was examined by adding the appropriate test variable to a basic equation linking physicians per capita to mortality, net of income.
RESULTS: The test variables dissolved or reduced the original correlation in two of the three samples, but the signs did not change from positive to negative, as would be expected on the basis of conventional biomedical theory. The available test variable (refugees) did not reduce the correlation for the 29 countries but a particular subset of countries was identified that did.
CONCLUSION: The conceptual and empirical analysis exposed the positive correlation as spurious, but the availability of medical specialists had little impact on mortality rates in competition with the social and economic variables that were used as controls.