OC01 Lower risk of atopic dermatitis among infants born extremely preterm compared with higher gestational age

s. Approximately one third (n=97, 34%) of trials used some form of an IGA. NorthAmerican-based studies used the IGA more frequently compared to European –based studies (77% vs. 30%, p<0.001). The IGA served as the primary outcome measure in 30% of trials.Of the 97 trials using an IGA, 62% used a static scale and 39% used a dynamic scale that referenced baseline severity, with one trial using both. Static IGA scales varied in size(between 4-6 point scales) with 80% using a 6 point scale. Instructions for performing the IGA appeared in 27% of the studies. The IGA score was analyzed as a continuous variable in22% of studies. The IGA plays a prominent role in clinical trials in atopic dermatitis, especially in NorthAmerica. However, our data reveal the instrument lacks basic standardization with variousscales and instructions being used across studies. Standardization of the instrument scale and instructions is needed urgently. Standardization will allow proper study of theinstrument’s measurement properties, such as content validity and interobserver reliability.ReferencesRehal B, Armstrong AW. Health outcome measures in atopic dermatitis: asystematic review of trends in disease severity and quality-of-life instruments1985-2010. PLoS One. 2011 Apr 13;6(4):e17520. doi: 10.1371/journal.pone.0017520.PubMed PMID: 21533286