Contents lists available at ScienceDirect Journal of Anxiety Disorders journal homepage: www.elsevier.com/locate/janxdis Cost-efectiveness of preventing child internalising problems: Results from the translational trial of Cool Little Kids at school entry Mary Lou Chatterton a, *, Jordana K. Bayer b,c,d , Lidia Engel a , Ronald M. Rapee e , Ruth Beatson b,c , Harriet Hiscock b,c,d , Lesley Bretherton c,d , Melissa Wake c,d , Cathrine Mihalopoulos a a Deakin University, Deakin Health Economics, Institute for Health Transformation, Geelong, VIC, Australia b School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia c Murdoch Children’s Research Institute, Melbourne, VIC, Australia d Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia e Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, Australia ARTICLE INFO Keywords: Cost-efectiveness Child, anxiety disorders Prevention Translation Randomised controlled trial ABSTRACT Objective: A translational trial evaluated the efectiveness of screening for inhibited childhood temperament, followed by a preventive parenting program -Cool Little Kids. This study determined the cost-efectiveness from societal and health sector perspectives using trial data. Method: Resources to deliver the screening and parenting sessions were determined from study records. Parents completed a questionnaire reporting resources used at one-year follow-up. Standard Australian unit costs were applied. Clinical outcomes for children and parental quality adjusted life-years (QALYs) were used to calculate incremental cost-efectiveness ratios (ICERs). Results: Total societal costs were lower, but non-signifcant for the intervention compared to the control group (mean diference -$500 p = 0.937). Total health sector costs were signifcantly greater (mean diference $1,956; p = 0.015). The intervention led to signifcantly fewer internalising symptoms (Strengths and Difculties Questionnaire (SDQ)-emotional difculties adjusted mean diference −0.5; p = 0.006), fewer children with SDQ-emotional symptoms in the abnormal range (24.2 % vs. 33.0 % p = .014) and fewer with diagnosed anxiety (44.2 % vs. 50.2 % p = 0.427). From the societal perspective, the intervention would likely be cost-efective. Health sector ICERs were $1,171/SDQ-emotional symptom decrease, $51/abnormal SDQ avoided and $77/ anxiety case avoided. Conclusions: This economic analysis alongside an implementation study provides an early indication that Cool Little Kids may be cost-efective. 1. Introduction Internalising (anxious/depressive) problems are among the most common difculties of childhood, afecting approximately 10–20 % of those at school age (Carter, Wagmiller, & Gray, 2010; Lawrence, Hafekost, & Johnson, 2016). By the time internalising disorders are treated (typically in adolescence), problems are often severe and entrenched, and treatment efectiveness can be limited (Kapornai & Vetro, 2008). Given that early internalising problems often have longer-term consequences and persist into adulthood, prevention and early intervention are key to producing a positive impact (Bayer, Rapee, & Hiscock, 2011). In recent years, a number of efective universal (targeting the general population); selective (tar- geting high-risk groups); and indicated (targeting groups already dis- playing symptoms of illness but not meeting full diagnostic criteria) in- terventions (Mrazek & Haggerty, 1994) have been developed and shown to be efective in the prevention of internalising problems in young people (Stockings, Degenhardt, & Dobbins, 2016). Additional evidence supports the cost-efectiveness of these programs (Lee, Barendregt, & Stockings, 2017; Mihalopoulos, Vos, & Pirkis, 2012; Simon, Dirksen, & Bogels, 2012; Simon, Dirksen, & Bögels, 2013). https://doi.org/10.1016/j.janxdis.2020.102191 Received 19 September 2019; Received in revised form 11 December 2019; Accepted 15 January 2020 Abbreviations: ADIS-CP-IV, Anxiety Disorders Interview Schedule for DSM-IV, Child Version, Parent Interview Schedule; AUD, Australian dollars; CCA, cost- consequence analysis; CI, confdence interval; GLM, generalised linear model; ICER, incremental cost efectiveness ratio; ITT, intention to treat; MBS, medicare beneft schedule; PBS, pharmaceutical beneft scheme; QALYs, quality adjusted life years; RCT, randomised controlled trial; RUQ, resource use questionnaire; SDQ, strengths and difculties questionnaire ⁎ Corresponding author at: Deakin University, Waterfront Campus, Room AD2.303-01, Locked Bag 20000, Geelong, VIC, 3220, Australia. E-mail address: m.chatterton@deakin.edu.au (M.L. Chatterton). Journal of Anxiety Disorders 70 (2020) 102191 Available online 17 January 2020 0887-6185/ © 2020 Elsevier Ltd. All rights reserved. T