Statistical Methods
psychiatric
Post hoc analyses were performed on data collected during the first esketamine treatment session. Data were analyzed from the 40-minute measurement taken on the first day of dosing, as this provided the greatest range of CADSS total scores (Confirmatory factor analyses of these data were performed to determine the goodness-of-fit of recently published 1- and 3-factor solutions (As neither the 1-factor nor 3-factor solutions proved satisfactory (data reported in Results section), an exploratory factor analysis using principal axis factoring and direct oblimin rotation was conducted to identify the underlying structure of CADSS items. The oblique direct oblimin rotation, appropriate for correlated factors, was used due to the inherent correlation often observed between psychiatric symptoms (Frequency counts of the CADSS items and the BPRS+ total scores were stratified according to investigator-reported severity of dissociation (i.e., “not reported,” “mild,” “moderate,” or “severe”). Given the skewed nature of the data, with most patients having low scores on the BPRS+ and CADSS, a Spearman rank correlation was performed to determine the relationship between the measures.To investigate the relationship between CADSS scores and investigator-reported severity of dissociation, equipercentile linking following the method of 