Data analysis
Analyses were performed using a modified intention-to-treat approach that included all randomized participants who completed the baseline session and at least one post or follow-up session (Fig. First, possible baseline differences on the questionnaires were assessed between randomized nasal spray groups, indicating no statistically significant differences (Table Further, to assess whether the overall magnitude of treatment-induced changes at the last session of the trial (T4) (calculated as change from baseline T0, i.e., reflecting the total change over phases I and II) were reliable for individual participants (more than can be expected by measurement error), the Reliable Change Index (RCI) [Finally, exploratory analyses were performed to investigate the potential influence of moderator variables on phase I treatment outcome. To do so, change from baseline scores were subjected to a mixed-effect model with ‘subject’ as random factor and ‘nasal spray’ (OT, placebo), ‘assessment session’ (T1 post, T2 follow-up) and the moderator variable included as fixed factors. Separate models were constructed to assess the modulating effect of concomitant psychosocial training (3 or more sessions per month, less than 3 sessions per month); medication use (present, not present; as listed in Table 