PRO10 Qualitative study to establish the content validity of the ABC-CFXS for evaluation of treatment efficacy in Fragile X Syndrome

Abstract

Objectives: Fragile X Syndrome (FXS) is a rare pediatric disorder that causes a range of developmental issues. Anxiety, social avoidance, irritability, and social unresponsiveness/lethargy represent the core behavioral symptoms of FXS. This qualitative study aimed to establish the content validity of the Aberrant Behavior Checklist-Community (ABC-CFXS), an assessment used to evaluate behavioral symptoms in FXS, to determine the accuracy by which it captures the caregiver perspective and it’s utility in measuring treatment efficacy in clinical trials of FXS. Methods: Ten caregivers of children with FXS were recruited via the National Fragile X Foundation. Caregivers participated in phone interviews conducted by a trained interviewer using a semi-structured interview guide. Thematic analysis was conducted. Results: All caregivers were mothers of children with FXS (mean age: 38y and 10y, respectively) and 80% reported that their child’s doctor described their FXS symptoms as moderate or severe. The most frequent behavioral symptoms reported in relation to FXS were: seeks isolation from others (70%), lack of interaction (60%), and aggressive to others (60%). Socially avoidant behaviors such as seeks isolation from others (70%), prefers to be alone (40%), and prefers solitary activities (20%) were reported and reflect the items on the ABC-CFXS Social Avoidance subscale. Aspects of misbehavior and irritability commonly reported (aggressive to others [60%], irritability [50%], temper tantrums/outbursts [50%], screaming/yelling inappropriately [40%], harming others [40%], stubbornness [30%]) mapped to the ABC-CFXS Irritability subscale items. Lack of interaction (60%) and lack of attention (50%) mapped to the ABC-CFXS Socially Unresponsive/Lethargic subscale items. Conclusions: This qualitative study demonstrates that the items in the ABC-CFXS Social Avoidance, Irritability, and Socially Unresponsive/Lethargic subscales represent relevant behavioral symptoms to caregivers of children with FXS. Evidence supporting the content validity of these subscales confirms the appropriateness of the ABC-CFXS for measuring treatment efficacy in FXS.L20042646652019-12-20 <br />