The burden of asthma in the Chicago community fifteen years after the availability of national asthma guidelines: the design and initial results from the CHIRAH study. - Weiss KB; Shannon JJ; Sadowski LS; Sharp LK; Curtis L; Lyttle CS; Kumar R; Shalowitz MU; Weiselberg L; Catrambone CD; Evans A; Kee R; et al. (Contemporary clinical trials, 2009)