Changing worldwide epidemiology of systemic lupus erythematosus.

Developed countries have better systemic lupus erythematosus survival rates than developing countries, or countries with lower economic performance. This is in part because of a higher human development index, defined by standard of living (a marker for gross domestic product), literacy rates, and life expectancy, with contribution from ethnic variations within individual countries, and unique environmental factors. Copyright 2010 Elsevier Inc. All rights reserved.