Outcomes
Two repeated-measure primary endpoints were specified. The first measure was the Clinical Global Impression Scale for Bipolar Disorder–Severity (CGI-BP-S), a reliable and valid assessment of global illness severity in bipolar disorder with excellent interrater reliability (20). The CGI-BP-S complements specific symptom severity scales by providing an integrated measure of illness severity that incorporates social and vocational functioning. Remission was defined as a CGI-BP-S score ,2. We defined a change of 0.50 points on the CGI-BP-S as a clinically meaningful
change based on previous drug-placebo differences, with mean
changes between 0.3 and 0.95 units (21–29).