Are parental changes related to improvements in preschool children's disruptive behaviours?

Abstract Objective To investigate whether changes in parenting after behavioural parent training in routine clinical care are associated with improvements in preschool children's disruptive behaviours. Method We evaluated changes after parent training in maternal and paternal self‐reports of parental discipline practices parenting sense of competence, and parents' ratings of child disruptive behaviours in parents of 63 children, with a one group pretest–posttest design. We also compared parenting parameters in this clinical sample with a nonclinical sample (n = 121). Results Mothers' self‐reports of parental discipline practices and parenting sense of competence significantly improved after behavioural parent training. Less over‐reactivity in both mothers and fathers was associated with fewer disruptive behaviours in children. After parent training, mothers' ratings of their discipline techniques did not differ anymore from those in the nonclinical sample. Conclusion Positive changes in parental discipline practices, particularly less over‐reactive parental behaviours, were related to a decrease of disruptive child behaviours.

informed by the degree of improvement in parenting skills and child behaviours, rather than applying a standard number of sessions.
The influence of changes in parenting style on children's behaviour may be different for fathers and mothers, because they may have different roles. Generally, mothers are the primary caretakers who spend most of the time with the children during daily routines, while fathers spend most of the time with the children during free time and sports.
It may be that fathers recognize behaviour problems in their children, but see mothers as primarily responsible for the child's behaviour (Fletcher, Freeman, & Matthey, 2011). It is therefore relevant to investigate the relation of changes in parenting behaviour in both mothers and fathers with child outcomes after parent training.
In our previous study (Van der Veen-Mulders, Hoekstra, Nauta, & van den Hoofdakker, 2018), we reported on the effectiveness of behavioural parent training for preschool children with disruptive behaviours, and on parental predictors of response. Both mother and father reported child behaviour problems decreased significantly after treatment. In this secondary analysis, we report on changes in parental discipline practices and sense of competence of both mothers and fathers after behavioural parent training, and possible associations with improvements in young children's disruptive behaviours. Given that inadequate parental disciplining is related to children's disruptive behaviours (Harvey, Metcalfe, Herbert, & Fanton, 2011;Rinaldi & Howe, 2012) and low levels of maternal self-efficacy is associated with maternal coercion (Bor & Sanders, 2004), we hypothesized that improvements of parental discipline practices and parental sense of competence on parenting through parent training may lead to fewer disruptive child behaviours.
There is some preliminary support that improvements in parental discipline techniques are related to improvements of child conduct problems after parent training, with more support in younger than in older children and more support in prevention studies compared to intervention studies (Forehand, Lafko, Parent, & Burt, 2014). Positive parenting skills, such as environmental restructuring, modelling, planning ahead, and praising are considered to be preventive for the development of disruptive behaviour problems (Cunningham & Boyle, 2002). A study in preschool children with conduct problems found that improvement of positive parenting skills, but not reduction of harsh and negative parenting, mediated the improvement in children's problem behaviour (Hess, Teti, & Hussey-Gardner, 2004). Furthermore, young children have been shown to respond more favourably to parent training if there were clear improvements in parenting practices (Beauchaine, Webster-Stratton, & Reid, 2005;Elizur, Somech, & Vinokur, 2017). Also, improvement of parental self-efficacy may be associated with better outcome of parent training. Among families of 2-year-olds it was found that improvements in mothers' reports of self-efficacy were significantly associated with improvements in child behaviour after behavioural parent training, but no such associations were found among fathers (Gross, Fogg, Garvey, & Julion, 2004). A study on a prevention program for preschool children with disruptive behaviour problems showed that changes in child behaviour were mediated by changes in negative parenting behaviour, but not by changes in parental self-efficacy (Hanisch, Hautmann, Plück, Eichelberger, & Döpfner, 2014). However, research on associations between changes in parental discipline strategies and parenting sense of competence with child outcomes after parent training is scarce, especially with respect to referred children. Also, little is known about the influence of changes in paternal parenting behaviours on child outcomes The main aim of the present study was to examine whether changes in parental discipline practices and parenting sense of competence of mothers and fathers of regularly referred preschool children after behavioural parent training, as provided in routine clinical practice, were associated with changes in parent-rated child behaviour problems. We hypothesized that improvements in parental discipline strategies and sense of competence would be associated with positive changes in child behaviour after parent training. As a secondary aim, we investigated whether parents reported less adequate parental discipline practices and lower parenting self-esteem before treatment than parents of preschool children from the general population. Consistent with previous studies (Lorber & Slep, 2015;Wittkowski, Dowling, & Smith, 2016), we expected parents in the nonclinical sample to rate more adequate discipline practices and higher levels of parenting sense of competence. Furthermore, we explored whether fathers and mothers differed on self-reported parenting parameters before treatment. Concerning differences on parenting between fathers and mothers, one could hypothesize that mothers of young children with disruptive behaviours show lower levels of sense of competence on parenting and less adequate parenting behaviours than fathers, assuming they focus more on daily care and discipline in their parenting role.

| Design
To enhance the ecological validity, we performed the study at our outpatient clinic for child-and adolescent mental health, in which parents of young referred children with disruptive behaviour problems were offered behavioural parent training as the first treatment step of routine care. In this study we evaluated changes in parental discipline

Key Practitioner Message
• Mothers' parental discipline practices and parenting sense of competence improve after behavioural parent training in routine care.
• Fathers' parental discipline practices do not improve after behavioural parent training and fathers' parenting sense of competence only slightly improves • A reduction in authoritarian, emotional, and harsh parenting after behavioural parent training is associated with improvement of the child's disruptive behaviour problems • Adaptations of existing parent training programs to the specific needs of fathers may be required VAN DER VEEN-MULDERS L. ET AL. practices, parenting sense of competence and externalizing child behaviour after behavioural parent training in routine clinical practice with a one group pretest-posttest design (n = 63). We collected outcome assessments directly before the start of the treatment (T1, pretest) and within 4 weeks after the last provided treatment session (T2, posttest), irrespective of whether the treatment was completed or not.
The time between pretest and posttest was approximately 17 weeks (M = 16.7, SD = 5.7) ranging from 6 to 42 weeks.
To compare externalizing child behaviour and parental discipline practices and parenting sense of competence before treatment with a nonclinical sample, we recruited a nonclinical sample of preschoolers (n = 121) and their parents in the Northern region of the Netherlands.

| Participants
The clinical sample consisted of 63 preschool children (aged 2.7-5.9 years) with disruptive behaviour problems and their parents, participating in behavioural parent training as part of routine care. The children in this sample had at least six attention-deficit/hyperactivity disorder (ADHD) symptoms in total or at least four symptoms in one symptom domain (attention deficit or hyperactivity/impulsivity) plus behaviour problems at home (i.e., score on the Intensity Scale of the Eyberg Child Behaviour Inventory (ECBI-I; (Eyberg & Pincus, 1999) ≥ 132 and/or at least two oppositional defiant symptoms, as assessed with a semi-structured interview with the parents (i.e., the Dutch version of the Parent Interview for Child Symptoms PICS-4; (Schachar, Ickowicz, & Sugarman, 2000). Participating parents gave written informed consent to use the routine care assessments for research purposes.
The study had been approved by the Medical Ethical Committee of the University Medical Centre Groningen. For more details of the study procedures, see Van der Veen-Mulders et al. (2018). Characteristics of the participating families are presented in Table 1. Although one of the secondary caretakers was a grandmother, we report on secondary caretakers as "fathers". Compared to the sample analyzed in our previous study (Van der Veen-Mulders et al., 2018), we could not analyze data of five families because they failed to provide T2 ratings.
As children in the nonclinical sample were significantly younger than children in the clinical sample, t(182) = -3.21, p = .002, and consisted of significantly more girls, χ 2 (1, n = 184) = 9.54, p = .002, we matched a subsample of n = 63 on age and sex out of the total nonclinical sample with the clinical sample.

| Treatment
The treatment protocol was based on two established behavioural treatments (Barkley, 1987;Forehand & Mcmahon, 1981), and the training was provided in group or individual format during twelve sessions: 2-hour group sessions by two psychologists with a master's degree, or 1-hour individual sessions led by one graduated psychologist. All therapists (in total 14) were experienced in delivering behavioural parent training to parents of children with behaviour problem and had received a training of 2 days specifically for the study  (87) Stepfather, n (%) 5 (11) Foster father, n (%) 1 (2) Note. ADHD = attention-deficit/hyperactivity disorder. ODD = oppositional defiant disorder. ECBI -I = Intensity Scale of the Eyberg Child behaviour Inventory. ECBI -P = Problem Scale of the Eyberg Child Inventory.
*Various information was not available on the nonclinical sample VAN DER VEEN-MULDERS L. ET AL. treatment. They were supervised weekly by an experienced cognitive behavioural therapist. Supervision included discussion of therapist adherence to the treatment protocol, and therapists completed a treatment integrity checklist after each session. Furthermore, all sessions were video recorded and at random analyzed, to check adherence to the protocol. A high rate of adherence to the protocol by the therapists was found (M = 96% of all topics covered, SD = 70%, range 79-100%). Parents could choose the individual or group format, which led to 55 parents (87%) starting the individual format.
The primary goal of the training was to improve positive child behaviours and to reduce disruptive behaviours. In order to enable parents to modify their child's behaviours, an important secondary goal was to improve parental discipline practices and to increase parenting sense of competence. Treatment was tailored for each child, based on target behaviour problems selected by the parents in the first session, and parents learned how to observe behaviour in antecedent-behaviour-consequence schedules, how to improve the parent-child interaction by playing with the child, how to adjust the antecedents (e.g., setting rules, giving adequate commands, structuring the environment, anticipating new situations) and consequences (e.g. praising and using rewards, ignoring, time out, and punishment) for Children whose parents stopped treatment, did not differ from the group completers in severity of externalizing behaviours before treatment, nor in total IQ. There was a greater percentage of boys (82%) in the group completers compared to the group treatment dropouts (68%).

| Measures
Parenting outcome measures were parental total and subscale scores on Parental ratings on the ECBI (Eyberg & Pincus, 1999) were used to assess children's behaviour problems. The ECBI is a 36-item inventory, rating both the intensity of problem behaviours (ECBI-I) and if the item-behaviour is a problem or not for the parents (ECBI-P). Parents in the nonclinical sample completed the questionnaires at home and parents in the clinical sample at home or at the clinic. Parents were instructed to complete the measurements separately and independently. The reliability and validity of the ECBI is supported in many studies across cultures and countries (Abrahamse et al., 2015).

| Statistical analysis
We conducted all main analyses with the total nonclinical sample (N = 121) and performed sensitivity analyses with the matched sample (N = 63).
To investigate differences between and within the clinical and nonclinical sample in mothers' and fathers' scores on the PS and PSOC, we used independent t-tests. The statistical significance level was set at p < .05. To correct for multiple testing, we adjusted significant p values with the Holm-Bonferroni procedure (Gaetano, 2013 In the clinical sample, changes in ECBI-I and ECBI-P ratings before (T1) and after (T2) behavioural parent training were analyzed with paired t-tests. Following the intent-to-treat principle, all analyses included both treatment completers (n = 44) and those who had stopped the treatment before the last session (n = 19). To investigate whether changes in parental discipline practices and parenting sense of competence were associated with improvements of children's disruptive behaviour problems after behavioural parent training we used multiple regression analyses, with ECBI-I and ECBI-P T2 scores, respectively, as dependent variables and total PS and PSOC pre-and posttreatment difference scores as independent variables, while controlling for ECBI-I or ECBI-P baseline ratings.
We controlled for treatment format (group vs individual) by adding treatment format as a covariate in the regression analyses. Predictors that were not significant were removed from the analyses. Finally, we investigated the possible association between attendance rates, and changes in both parents' parental discipline practices with Pearson correlations.  Both in the clinical and the nonclinical sample, fathers and mothers did not significantly differ in mean total baseline scores on the PS and the PSOC. Regarding the subscale scores, only a significant difference between mothers and fathers was found in the clinical sample on the PS subscale over-reactivity; mothers reported significantly higher levels of emotional and harsh discipline strategies than did fathers, t (109) = 2.48, p < .015.  = .002) and for mothers (r = .259, p = .042): the more they were present during the sessions, the larger the changes in parenting.

| Changes in parental discipline practices and parenting sense of competence
Independent t tests indicated that maternal ratings on the total PS after BPT did not differ anymore from mothers' ratings in the nonclinical sample, t(178) = 0.493, p = .623, nor did ratings on the PS subscales. Significant differences between maternal PSOC ratings after BPT in the clinical sample and mothers' ratings in the nonclinical sample remained, both on the total score, t(167) = 3.57, p < .001, and on the PSOC subscales. After treatment, fathers in the clinical sample still differed from fathers in the nonclinical sample on all scales, except the PS subscale laxness. As mentioned before, fathers in the clinical sample did also not differ in lax parenting discipline practices from fathers in the nonclinical sample before treatment.
After behavioural parent training, mothers in the clinical sample did not differ anymore from fathers in their ratings on the PS overreactivity subscale. But now, mothers rated significantly more adequate discipline practices than did fathers on the total score of the PS, t(105) = 2.78, p = .007 and on the laxness subscale, t(105) = 2.36, p = .007 (see T2 scores in Table 3). Again, no differences were found between mothers and fathers after treatment regarding parenting sense of competence (see T2 scores in Table 3).
Sensitivity analyses yielded similar results, except for over-reactivity in fathers: fathers in the clinical sample did not differ in overreactivity after parent training compared to fathers in the nonclinical sample.

| Changes in parental discipline practices and parenting sense of competence in relation to improvements children's in children's disruptive behaviour problems after behavioural parent training
Changes of both mothers and fathers ratings on the ECBI from pre-to posttreatment are reported in Table 4. Mothers' ECBI-I ratings before treatment statistically predicted ECBI-I ratings after behavioural parent training, R 2 = 0.36, F (1,60) = 33.9, p < .001, and mothers' ECBI-P ratings at T1 predicted their ratings at T2, R 2 = 0.18, F (1,60) = 13.5, p = .001. Improvements in overall maternal discipline practices and sense of competence on parenting added significantly to this pre-

| DISCUSSION
Our main finding was that in both fathers and mothers a reduction in authoritarian, emotional and harsh parenting after behavioural parent training was associated with improvement of the child's disruptive behaviour problems. This finding was in line with our hypothesis and with two previous studies on mediators of treatment for young children with conduct problems (Beauchaine et al., 2005;Hanisch et al., 2014). As expected, and also in line with previous studies (Ghuman et al., 2007), we found both fathers and mothers in the clinical sample reporting more inadequate parenting skills and lower parenting sense of competence before parent training than parents of children in the nonclinical sample. In a previous paper we had already reported that our behavioural parent training decreased disruptive behaviours (Van der Veen-Mulders et al., 2018).
An overreactive parenting style can be seen as a form of parental coercion. Bor and Sanders (2004) point to parental reinforcement of negative child behaviours and vice versa (see also Lorber & Slep, 2015). Parental coercive behaviour may be one of the most crucial risk factors for future conduct problems (Bor & Sanders, 2004).
Overreactive parenting models hostile behaviour, and may undermine children's self-regulation and willingness to comply (Lorber & Slep, 2015). High levels of disruptive child behaviour problems, in turn, may elicit harsh and uncontrolled parenting disciplining practices and such inadequate over-reactive parenting reinforces and elevates conduct problems (Lorber & Slep, 2015) . Reducing overreactivity in parents of young children with ADHD symptoms is especially important, as over-reactivity has been shown to mediate the relation between early hyperactivity and later oppositional behaviours (Harvey et al., 2011). Thus, behavioural parent training appears to mitigate the risk factor of coercive parenting, especially in mothers, at least in the short run. In our study, mothers' overreactive parenting in the clinical sample clearly decreased after behavioural parent training. This finding is even more important, as maternal over-reactivity is known to increase over time (Lorber & Slep, 2015).
Although mothers' laxness in disciplining also significantly improved after behavioural parent training, these changes were not found to be associated with changes in child behaviour, maybe due to the strong predictive value of the over-reactivity factor. Interestingly, in contrast to parental over-reactivity, laxness was not found to be predictive for more symptoms of oppositional defiant disorder in 3-year old children, at the age of 6 (Harvey et al., 2011). Thus, reducing harsh and emotional maternal parenting strategies may be more important for the improvement of child behaviour problems, than reduction of permissive disciplining.
Fathers reported no improvements in the use of parental discipline practices and only a significant change in parenting sense of competence, albeit with a small effect size. Perhaps, due to the improvement of their children's behaviour, fathers experienced their parenting role as less demanding and felt themselves somewhat more competent.
A lack of effect of behavioural parent training on paternal parental discipline practices is in line with findings previous study in young children with ADHD (Webster-Stratton, Reid, & Beauchaine, 2011), but in contrast to another study on early-inset conduct problems (Websterstratton et al., 2004). Although there were only significant improvements in mothers' use of parental discipline practices, but not in that of fathers, improvement in both parents was associated with higher attendance, with a weak correlation in mothers and a moderate participating in treatment as less important than did mothers (Niec, Barnett, Gering, Triemstra, & Solomon, 2015). It may also be that fathers profit better from adapted formats of behavioural parent training, as was shown in a study on fathers of older children with ADHD (Fabiano et al., 2012). Although fathers' over-reactivity in our study did not change significantly after treatment, there was an association between changes in paternal overreactivity and changes in child behaviour. Therefore, it may be important for therapists to choose reducing over-reactivity as a focus of parent training when working with fathers.
Previous studies on parenting of parents of preschool children with conduct problems showed that changes in observed positive parenting strategies, but not in negative, were associated with change in children's behaviour (Gardner, Hutchings, Bywater, & Whitaker, 2010).
In our study, we did not evaluate changes in positive parenting practices, but as our treatment protocol contains all these techniques and focuses on eliciting positive parent-child interactions one may hypothesize that positive parenting increased after the behavioural parent training. The interplay between positive and negative parenting may be a topic future research. For example, to investigate how treatment-related changes in positive parenting might affect parent's use of negative parenting strategies.
Regarding parenting sense of competence, both fathers and mothers showed significant improvements after behavioural parent training, but these were not associated with improvements in child behaviour. Moreover, after the parent training parents still experienced a significantly lower parenting sense of competence than parents in the nonclinical sample. Although their child's behaviour problems had decreased, the remaining problems apparently were still demanding for both parents.
At pre-treatment, mothers in the clinical sample reported significantly higher levels of over-reactivity than fathers. On all the other parental parameters we found no significant differences between mothers and fathers in this group. In the nonclinical sample mothers and fathers did not differ on any of the parenting variables. As expected, parents of children in the clinical sample reported more overreactivity and lower levels of parenting sense of competence before treatment than parents of children in the nonclinical sample.
Mothers in the clinical sample, but not fathers, reported more lax parenting at pre-treatment than did mothers in the control sample.

| Strengths and limitations
Strengths of our study were its high external validity with the embedding within clinical practice and the use of both mother and father outcome ratings on parenting. However, notable limitations were the lack of a control group, the lack of measurements of changes in parenting at various time points during the training (thus inability to evaluate mediation or directionality between parenting changes and child outcomes), the modest sample size, the fact that ratings of child behaviour and parenting were exclusively through parents' self-report, and the lack of measures related to positive parenting. We also did not measure the extent to which mothers and fathers utilized recommended parenting strategies at home, nor if this was related to outcomes. Further research is needed to find out whether these are related.
Because of the absence of a control group, we cannot attribute the changes in maternal parenting to the behavioural parent training, although mothers discipline practices after the treatment did not differ anymore from mothers in a nonclinical sample. Some of the changes in child behaviour could be due to maturation, as the time elapsed between pre-and post-treatment could be as long as 42 weeks.
Finally, the modest sample size, especially regarding fathers, may have affected study power and our negative findings regarding changes in parenting after behavioural parent training should be seen in this light.

| Clinical implications
Findings of this study displayed that maternal parenting discipline practices and parenting sense of competence improved after behavioural parent training in an outpatient mental health clinic. In particular, the reduction of harsh and emotional parenting in both parents was related to changes in the child's behaviour. Assessment and change of uncontrolled and harsh parenting practices in both parents should thus be an important focus of any parent training program.
Although there was a high treatment attendance, fathers' parenting discipline practices did not change after behavioural parent training, maybe due to a less prominent role in daily child care and disciplining. However, assessment of readiness for change, and a pre-treatment motivational phase, may be needed to improve outcome on paternal parenting practices. Furthermore, when fathers are involved in parent training, therapists may focus more on decreasing paternal over-reactivity. In addition, adaptations of existing treatment protocols to the specific needs of fathers (e.g. (Fabiano, 2007) may be required. Perhaps there could be enhanced effects for both mothers and fathers by teaching specific strategies consistent with their caregiver roles.

CONFLICT OF INTEREST
Pieter Hoekstra has received funding from Shire for a research project and has been member of a Shire advisory board meeting. Barbara van den Hoofdakker and Lianne van der Veen-Mulders receive royalties as one of the editors of "Sociaal Onhandig" (published by Van Gorcum), a Dutch book for parents of children with PDD-NOS and ADHD that is being used in parent training. Barbara van den Hoofdakker is and has been involved in the development and evaluation of several parent training programs, and is and has been a member of Dutch ADHD guideline groups, all without financial interests.

This study was financed by The Netherlands Organization for Health
Research and Development (ZonMw), grant-number 80-82435-98-9030.