Review articleEfficacy of behavioral interventions for reducing problem behavior in persons with autism: An updated quantitative synthesis of single-subject research
Introduction
Problem behaviors such as aggressive, stereotyped, and self-injurious behavior are highly prevalent among persons with autism (e.g., Matson and LoVullo, 2008, Murphy et al., 2009). The problem behaviors bring along major risks for the individual with autism and his/her family with regard to their physical, emotional, and social well-being, and can accordingly reduce their quality of life (e.g., Walsh, Mulder, & Tudor, 2013). In order to reduce problem behavior in persons with autism, several (cognitive-)behavioral interventions are used, such as differential reinforcement of other behavior (DRO), differential reinforcement of incompatible behavior (DRI), differential reinforcement of alternative behavior (DRA), antecedent control, antecedent exercise, noncontingent reinforcement, social stories, picture exchange communication system (PECS) interventions, and mindfulness-based interventions.
Many studies published in the domain of behavioral intervention research for reducing problem behavior among persons with autism are single-subject studies. In order to synthesize the results of these studies and to study which variables are moderating the effectiveness of the behavioral interventions, meta-level research is needed. Accordingly, Campbell (2003) conducted a quantitative synthesis of single-subject studies published between 1966 and 1998 on the efficacy of behavioral interventions for reducing problem behavior in persons with autism. In the meantime many more studies were published in this domain (cf. Matson & LoVullo, 2009), and an update of the meta-analysis of Campbell (2003) was warranted. The present article provides a double update of this meta-analysis: one from a methodological perspective and one from a temporal perspective.
First, we applied a methodological update. Campbell (2003) calculated three single-subject nonparametric statistics for estimating the effects of the behavioral treatments: the percentage of nonoverlapping data (PND; Scruggs, Mastropieri, & Casto, 1987), the percentage of zero data (PZD; Scotti, Evans, Meyer, & Walker, 1991), and the mean baseline reduction (MBLR; Kahng, Iwata, & Lewin, 2002). However, in the meantime new single-subject nonparametric statistics have been developed that avoid some of the drawbacks of the earlier developed statistics (e.g., see Heyvaert et al., in press, Parker and Brossart, 2003, and Parker, Vannest, & Davis, 2011, for overviews). Therefore we included the percentage of data points exceeding the median of baseline phase (PEM; Ma, 2006) and the percentage of all nonoverlapping data (PAND; Parker, Hagan-Burke, & Vannest, 2007) in our update. In contrast with some other recently developed nonparametric statistics, PEM and PAND have comparable ease of use to PND, PZD, and MBLR (cf. Parker et al., 2011): All five effect sizes can easily be calculated by practitioners.
PND is the most frequently used effect size index across single-subject syntheses in the field of disability research (cf. Maggin, O’Keeffe, & Johnson, 2011). In order to meet PND's main drawback (i.e., the deficient performance in the presence of data outliers in the baseline phase) Ma (2006) developed PEM as an alternative effect size for summarizing results of single-subject studies: Whereas PND takes into account the one most extreme value of the baseline phase, and refers to the percentage of data points in the treatment phase that exceeds this most extreme value, PEM takes into account the median value of the baseline phase. PEM leans very close to PND in its calculation and interpretation. PAND was also developed to meet the drawbacks of PND, but conceptually deviates a bit more from it. The main advantages of PAND over PND are: (1) PAND uses all data from the baseline and intervention phases, avoiding the criticism leveled at PND for overemphasis on one unreliable data point; and (2) PAND can be translated to Pearson's Phi and Phi2, and because Phi and Phi2 have known sampling distributions, p values are available, statistical power can be estimated, and confidence intervals can be included to indicate effect size reliability (Parker et al., 2007). Accordingly, for the present study we calculated PND, PZD, MBLR, PEM, and PAND for estimating the effects of behavioral interventions for reducing problem behavior in persons with autism. We compared these five nonparametric statistics with one another and examined to what extent they agreed in the analysis of the same data set. Answers to such questions are needed for scientist-practitioners to confidently use nonparametric statistics in the analysis of single-subject data (Parker & Brossart, 2003).
Second, for the temporal update we included single-subject studies published between 1999 and 2012 in our meta-analysis. Analogous to what Campbell (2003) did for the studies published between 1966 and 1998, we summarized single-subject studies published between 1999 and 2012: We studied the overall efficacy of behavioral interventions in reducing problem behavior in individuals with autism, examined whether some behavioral interventions were more effective than others, and investigated which variables, if any, moderated the overall efficacy of the behavioral interventions. Furthermore, we compared the two sets of studies and examined whether there were differences in the use of behavioral interventions and their effectiveness in reducing problem behavior in individuals with autism.
Accordingly, the research questions addressed in the current review were: (1) What is the overall efficacy of behavioral interventions in reducing problem behavior in individuals with autism; (2) Are some behavioral interventions more effective than others in reducing certain types of problem behavior in individuals with autism; (3) Do participant, treatment, or experimental variables influence the overall efficacy of behavioral interventions; (4) Are there any differences between the three older effect sizes (i.e., PND, PZD, and MBLR; Campbell, 2003) and the two more recently developed effect sizes (i.e., PEM and PAND) regarding treatment efficacy and moderating variables; and (5) Are there any differences between the single-subject studies published between 1966 and 1998 (Campbell, 2003) and the studies published between 1999 and 2012 regarding the use of behavioral interventions and their effectiveness in reducing problem behavior in individuals with autism?
Section snippets
Inclusion and exclusion criteria
We aimed at reviewing single-subject studies on behavioral interventions for reducing problem behavior in people with autism. The inclusion criteria were defined in the same way as Campbell (2003) did. First, the review included studies about participants diagnosed with autistic disorder. An article was included if at least one participant was diagnosed with autism. When articles included multiple individuals, only those participants diagnosed with autism were included in the review.
Results
Two hundred and thirteen studies representing 358 persons with autism met the inclusion criteria and were included in the statistical analyses. Detailed information about the participants, treatments, and experimental studies is presented in Table 1, Table 2, Table 3 respectively.
To answer the first research question we examined the overall efficacy of the behavioral interventions. Across all participants the averages were 74.9%, 44.7%, 70.2%, 91.4% and 91.9% for PND, PZD, MBLR, PEM, and PAND
Discussion
The present study aimed to answer five questions: (1) What is the overall efficacy of behavioral interventions in reducing problem behavior in individuals with autism; (2) Are some behavioral interventions more effective than others in reducing certain types of problem behavior in individuals with autism; (3) Do participant, treatment, or experimental variables influence the overall efficacy of behavioral interventions; (4) Are there any differences in the conclusions for the five calculated
References (28)
Efficacy of behavioral interventions for reducing problem behaviour in persons with autism: A quantitative synthesis of single-subject research
Research in Developmental Disabilities
(2003)- et al.
A multilevel meta-analysis of single-case and small-n research on interventions for reducing challenging behavior in persons with intellectual disabilities
Research in Developmental Disabilities
(2012) - et al.
Trends and topics in autism spectrum disorders research
Research in Autism Spectrum Disorders
(2009) - et al.
Risk factors for challenging behaviors among 157 children with autism spectrum disorder in Ireland
Research in Autism Spectrum Disorders
(2009) - et al.
Evaluating single-case research data: A comparison of seven statistical methods
Behavior Therapy
(2003) - et al.
Psychosocial interventions for reducing vocal challenging behaviour in persons with autistic disorder: A multilevel meta-analysis of single-case experiments
Research in Developmental Disabilities
(2013) - et al.
Predictors of parent stress in a sample of children with ASD: Pain, problem behavior, and parental coping
Research in Autism Spectrum Disorders
(2013) UnGraph Version 5 [Computer software]
(1997–2014)- et al.
Behavioural treatment of challenging behaviours in individuals with mild mental retardation: Meta-analysis of single-subject research
American Journal on Mental Retardation
(2006) - et al.
Updating a meta-analysis of intervention research with challenging behaviour: Treatment validity and standards of practice
Journal of Intellectual & Developmental Disability
(2009)
A meta-analysis of intervention effects on challenging behaviour among persons with intellectual disabilities
Journal of Intellectual Disability Research
Systematic review of restraint interventions for challenging behaviour among persons with intellectual disabilities: Focus on effectiveness in single-case experiments
Journal of Applied Research in Intellectual Disabilities.
Randomization and data-analysis items in quality standards for single-case experimental studies
Journal of Special Education
The impact of functional analysis on the treatment of self-injurious behavior
Cited by (82)
Development and Implementation of a Function-Based Clinical Interview to Evaluate Childhood Behavior Problems
2023, Cognitive and Behavioral PracticeElements of care that matter: Perspectives of families with multiple problems
2022, Children and Youth Services ReviewIndividualized Parent-Mediated Behavioral Treatment for Challenging Behavior: A Program Description
2024, Behavior ModificationEffect of Yoga Intervention on Problem Behavior and Motor Coordination in Children with Autism
2024, Behavioral Sciences