Repeatability of response to XXXX medications.

@entity1 @entity565 @entity19608 @entity4184
BACKGROUND: Pharmacogenetic studies of drug response in @entity565 assume that @entity1 respond consistently to a treatment but that treatment response varies across @entity1 ; however, no formal studies have demonstrated this. OBJECTIVE: To determine the repeatability of commonly used outcomes for treatment response to @entity565 medications: bronchodilator response, FEV(1), and PC(20). METHODS: The Childhood Asthma Management Program was a multicenter clinical trial of @entity1 randomized to receiving @entity4184 , @entity19608 , or placebo. We determined the intraclass correlation coefficient (ICC) for each outcome over repeated visits over a period of 4 years in the Childhood Asthma Management Program by using mixed-effects regression models. We adjusted for the covariates age, race/ethnicity, height, family income, parental education, and symptom score. We incorporated each outcome for each @entity1 as repeated outcome measurements and stratified by treatment group. RESULTS: The ICC for bronchodilator response was 0.31 in the @entity4184 group, 0.35 in the @entity19608 group, and 0.40 in the placebo group, after adjusting for covariates. The ICC for FEV(1) was 0.71 in the @entity4184 group, 0.60 in the @entity19608 group, and 0.69 in the placebo group, after adjusting for covariates. The ICC for PC(20) was 0.67 in the @entity4184 and placebo groups and 0.73 in the @entity19608 group, after adjusting for covariates. CONCLUSION: The within-treatment group repeatability of FEV(1) and PC(20) is high; thus, these phenotypes are heritable. FEV(1) and PC(20) may be better phenotypes than bronchodilator response for studies of treatment response in @entity565 .
