For the last two years, John Mullahy and Sheryl Magzamen and I have been working on an analysis of the apparent racial differences in normal lung function and the contribution of socioeconomic status to those patterns.
Our goal was to investigate whether alternative statistical methods (quantile regression) might better illustrate the effects of educational achievement (as a proxy for SES) across the entire distribution of lung function in a population, and to understand variability across racial/ethnic groups. In addition, we wanted to understand how sample selection criteria used to generate reference equations for normal lung function might alter estimates of the effect of socioeconomic status.
The resulting paper, Understanding Socioeconomic and Racial Differences in Adult Lung Function, has just been published in the current (September 2011) issue of the American Journal of Respiratory and Critical Care Medicine, along with an editorial (FEV1 in the Suburbs) authored by Peter Wagner of the Univ of California San Diego. The Univ of Wisconsin School of Medicine and Public Health has also issued a press release, with the following great quote from John about sample selection:
Seemingly subtle issues in how samples are constructed and data are analyzed ultimately have important implications for how we understand the roles of race and socioeconomic status as determinants of respiratory health.