Investigation of the Factor Structure and Differential Item Functioning of the Child and Adolescent Mindfulness Measure (CAMM): Analysis of Data from a School-Based Cluster Randomised Controlled Trial

Abstract Objectives This study used data from a randomised controlled trial of school-based mindfulness programme in the UK to investigate structure and performance 10-item Child Adolescent Mindfulness Measure (CAMM). Method The included 7924 children adolescents aged 11 14 years. Participants provided CAMM at pre-intervention, 7 months (post-intervention) 1 year. Exploratory factor analysis (EFA) pre-intervention was undertaken. Multiple indicators multiple causes (MIMIC) models were fitted responses differential item functioning across groups defined by gender, year group ethnicity. Response shift resulting receiving investigated fitting MIMIC compare between intervention control arms. Results EFA results indicated that 2-factor model good fit. Eight items associated with first factor, while remaining two items, which specifically addressed avoiding unwanted thoughts feelings, second factor. findings girls scored lower (ostensibly less mindful) on 4 than boys had same latent level mindfulness; as result programme, participants one (“At school, I walk class without noticing what I’m doing”) after holding constant. Conclusions Findings indicate has late childhood early adolescence. While we did observe some differences how individual performed groups, these small compared overall variability scores. Preregistration Current trials ISRCTN86619085.