Sample
The sample consists of N=8,803 children and adolescents who were referred to Karakter Child- and Adolescent Psychiatry in The Netherlands, between March 2012 and May 2017. The sample included N=6,299 (71.6%) boys, Mage at entry = 9.1 years, SD = 3.7, and N=2,504 (28.4%) girls, Mage at entry = 10.7 years, SD = 4.2. Karakter offers academic, highly specialized care and is specialized in neurodevelopmental disorders.
Clinical DSM-IV-TR [18] (APA, 2000) and DSM-5 diagnoses [19] (2014 and later; APA, 2014) were established by a multidisciplinary team based on information gathered by a child psychiatrist (developmental history, child observation and psychiatric assessment), by a child psychologist, and review of clinical and prior records, including information available from school or other professional institutions involved with the child. Thus, a consensus diagnosis was assigned, which is seen as most reliable, compared to structured interviews when broad diagnostic categories are investigated [20] (Leckman, Sholomkas, Thompson, Belanger, & Weissman, 1982). We focused on 5 main disorders: Attention Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Conduct Disorder/Oppositional Defiant Disorder (CD/ODD), Anxiety disorders and Mood disorders.
Before the first appointment at the clinic, parents were invited to complete several questionnaires using a Routine Outcome Monitoring system (ROM), to assess a range of variables, such as age, gender and country of birth. The questionnaires included the Child Behaviour Checklist (CBCL) [21] (Achenbach & Rescorla, 2007), to asses current psychopathology and problem behaviour, and Kidscreen-27 [22] (Ravens-Sieberer, et al., 2011) for assessing quality of life. Treatment was monitored with an Electronic Health Record system (EHR). Data on total treatment minutes were derived from the EHR. The present study was approved by the institutional review board of Karakter Child- and Adolescent Psychiatry on June 20th 2017.
Procedures
All data was derived from ROM and EHR. Cases were pseudoanonymized upon withdrawal and therefore no individual health records were assessed and privacy remained secured. Data was directly put into an IBM SPSS statistics 25 file.
Measurements
Emotion dysregulation
An 18-item emotion dysregulation construct was created based on expert ratings of relevance for ED in all CBCL items [17] (Samson et al., 2014). In this study, the CBCL preschool version (age 1.5-5) and school age version (age 6-18) was used. Item 18 (self-harm and suicidal tendencies), 91 (contemplating suicide) and 97 (threatening people) are missing from the preschool CBCL-EDI and therefore, the CBCL-EDI for this age group consisted of 15 items instead of 18 (See table 1). Internal consistency in the present study was proven to be very good (Cronbach’s alpha =.82 and .85 respectively). See table S1.
Quality of life
Kidscreen-27 was used to assess quality of life (Physical well-being, Psychological well-being, Autonomy and Parent relation, Peers and social support and School environment) in children and adolescents according to parent reports [22] (Ravens-Sieberer et al., 2001). Low scores on one of the subscales or a low total score indicate low subjective health and well-being. Age norms for Kidscreen-27 range from 8-18 years old. Therefore, in the current study, Qol was not assessed for the preschool age group.
Treatment duration
Treatment information for all referred children was registered in EHR system User. Treatment duration was calculated as the total amount of minutes spend on finalized (in)direct treatments of the child as registered by clinicians. As this registration is vital to receive financial compensation for offered services, monthly reminders were send to clinicians to accurately register their appointments in addition to individual reminders in case certain planned patient appointments have not been registered by the end of the month. Therefore, this information was considered to be complete and accurate.
Statistical analyses
IBM SPSS statistics 25 was used for statistical analysis. Dichotomous disorder categories were created for each clinical diagnosis (e.g. ADHD, yes = 1, no = 0). Therefore, children with comorbidities could be in more than one disorder category. (e.g. ADHD = yes, ASD = yes). Cases were deleted from analysis only when age was entered incorrectly (e.g. parent answered with own age instead of the child’s) or when data was missing for CBCL, Kidscreen-27 or treatment duration (e.g. end of treatment was unknown because of ongoing treatment; Table S2 and S3). Analyses were run separately for the preschool age and school age, because the items in the two CBCL versions were not fully compatible. Descriptives were used to provide an overview of demographics, CBCL-EDI, Kidscreen-27 and treatment minutes for the disorder categories. Two separate sets of logistic regression analyses were performed for each of the five dichotomous disorder categories: (1) CBCL-EDI total score as independent variable to compare the relative strength of association between total ED and each disorder category versus all others, (2) each CBCL-EDI item as independent variable to examine the ED aspects that were relatively most distinguishable for each disorder category versus all others. For each disorder-category, items were ordered by most prevalent to least prevalent based on frequency scores of ‘often/clearly present’ ratings.
In addition, linear regression analyses were performed to predict Qol and treatment duration. First, we evaluated if the CBCL-EDI total score predicted Qol and treatment duration as such. Next, we evaluated if the CBCL-EDI total score had additive predictive value for Qol and treatment duration beyond diagnosis. Finally, we examined if the CBCL-EDI total score predicted Qol and treatment duration more in the context of any of the specific disorder categories by adding the interaction between diagnosis and CBCL-EDI in the regression analyses. Age and gender were entered by default in all regression analyses. Linear regression results were corrected for multiple testing by False Discovery Rate (FDR), [23] (FDR; Benjamini, Krieger, & Yekutieli, 2006).