The impact of measurement on clinical trials: Comparison of preliminary outcomes of a brief mobile intervention for autistic adults using multiple measurement approaches.

Initial studies of the emotional safety plan (ESP), a new, brief telehealth and mobile intervention to support autistic adults to cope with periods of distress, have reported feasibility and acceptability (Bal et al., 2023, Autism, 1-13). Herein we report the preliminary clinical outcomes of thirty-six autistic adults who developed a personalized ESP, with a specific interest in comparing "outcomes" demonstrated by different instruments and assessment frequencies in order to inform outcome measurement in future clinical trials. Comparison of pre-intervention baseline to post-monitoring outcome (pre-post) anxiety symptoms (Generalized Anxiety Disorder-7 [GAD-7]) and depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]) revealed medium effect sizes for reduction in symptoms, though, low effect sizes were observed for pre-post Adult Self-report Anxiety and Depressive Problems scales and the Emotion Dysregulation Inventory Reactivity and Dysphoria scales. Weekly assessments showed an initial decrease in GAD-7 anxiety symptoms but no effect on weekly PHQ-9 depressive ratings. Ecological momentary assessment (EMA) data suggested that, when participants reported feeling sad or agitated and used the ESP, reduced negative feelings and increased positive states were reported in subsequent EMA. Perhaps not surprisingly, preliminary outcomes of these feasibility trials differed depending on measure chosen. Implications for the design of clinical trials are discussed.