Single-subject Studies Research Articles

Meta-Analysis of Single-Subject Design Studies in Stuttering Treatment

배경 및 목적: 임상가가 증거기반치료를 수행하는데 가장 높은 수준의 증거를 제공하는 연구는 체계적인 리뷰 혹은 메타분석이다. 지금까지 말더듬치료와 관련된 메타분석은 주로 집단 연구방법을 이용한 개별연구를 대상으로 하였으며 참여자의 개별적인 특성을 잘 나타낼 수 있다는 장점이 있는 단일대상연구에 대한 말더듬치료 메타분석 연구는 없었다. 이에 본 연구는...

FMRI activation mapping using wavelet-based SPM (WSPM) integrated with gray-matter graphs

In many fMRI task-evoked studies, localized brain activity can be detected by GLM fitting and statistical hypothesis testing. Statistical parametric mapping (SPM) is the classical method that requires Gaussian pre-smoothing of the data. Instead, the wavelet transform provides a compact representation of activation patterns. Wavelet based SPM (WSPM) is an extension of SPM that combines wavelet processing with voxel-wise statistical testing. However, classical wavelets used in WSPM are designed for regular Euclidean grids and thus not adapted to the convoluted nature of the cerebral cortex. We recently showed how WSPM using graph wavelets tailored to the gray-matter structure of the cortex can improve detection of brain activity in single-subject studies. Here we extend this approach to group-level analysis by modifying the design of the brain graph.

Efficacy of behavioral interventions for reducing problem behavior in persons with autism: an updated quantitative synthesis of single-subject research.

Problem or challenging behaviors are highly prevalent among persons with autism and bring along major risks for the individual with autism and his/her family. In order to reduce the problem behavior, several behavioral interventions are used. We conducted a quantitative synthesis of single-subject studies to examine the efficacy of behavioral interventions for reducing problem behavior in persons with autism. Two hundred and thirteen studies representing 358 persons with autism met the inclusion criteria and were included in the statistical analyses. Overall, we found that behavioral interventions were on average effective in reducing problem behavior in individuals with autism, but some interventions were significantly more effective than others. The results further showed that the use of positive (nonaversive) behavioral interventions was increasing over time. The behavioral interventions were on average equally effective regardless of the type of problem behavior that was targeted. Interventions preceded by a functional analysis reduced problem behavior significantly more than interventions not preceded by a functional analysis. Finally, treatment and experimental characteristics, but not participant characteristics, were statistically significant moderators of the behavioral treatment effectiveness.

Children with Autism in the Inclusive Preschool Classroom: A Systematic Review of Single-Subject Design Interventions on Social Communication Skills

Changes in legislation have led to an increased push for children with autism spectrum disorder to be educated in classrooms with typically developing peers. This systematic review of the literature between the years of 2005 and 2012 aimed to identify effective interventions to support the children with autism spectrum disorder in the inclusive preschool classroom. Single-subject studies concerning the improvement of social communication skills for children with autism spectrum disorder in inclusive preschools were identified through systematic searches of electronic databases using key terms, journal hand searches, and ancestral searches of identified articles. Data were extracted from the resulting 16 articles to (a) examine rigor of design, (b) evaluate intervention effectiveness using visual analysis and percentage non-overlapping data (PND), and (c) determine evidence-based practices. Results suggest a range of effective interventions to improve the social communication skills for children with autism spectrum disorder in inclusive preschool classrooms. Suggestions for future research are discussed.

The reorganization of motor network in hemidystonia from the perspective of deep brain stimulation.

Hemidystonia is usually 'secondary' to structural lesions within the cortico-striato-pallido-thalamic or the cerebello-thalamo-cortical loops. Globus pallidus internus Deep Brain Stimulation (GPi DBS) is a validated technique in the treatment of primary dystonia and still under assessment for secondary dystonia. Results of DBS in hemidystonia are limited and heterogeneous. Further knowledge concerning motor network organization after focal brain lesions might contribute to the understanding of this mitigated response to DBS and to the refinement of DBS indications and techniques in secondary dystonia. This study aimed to identify movement-related functional magnetic resonance imaging (fMRI) activation patterns in a group of hemidystonic patients in comparison to healthy controls (HC). Further analysis assessed recruitment pattern in different patient subgroups defined according to clinical and radiological criteria relevant to GPi DBS eligibility (hyperkinetic/hypokinetic and prepallidal/postpallidal). Eleven patients and nine HC underwent fMRI with a block-design alternating active and rest conditions. The motor paradigm consisted of self-paced elbow flexion-extension movements. The main results were as follows: single-subject studies revealed several activation patterns involving motor-related network regions; both ipsilesional and contralesional hemispheres showed abnormal patterns of activity; compared with HC, hemidystonic patients showed decreased brain activity in ipsilesional thalamus, pallidal and temporal areas during affected arm task execution; 'hypokinetic' subgroup was commonly related to widespread bilateral overactivity. This study provides additional arguments for case-by-case assessment of DBS surgery indication and target selection in hemidystonia. Single-lead approach might be unable to modulate a highly disorganized network activity in certain patients with this clinical syndrome.

Meta-Analysis of Single Subject Design Studies on Positive Behavior Support for Students with Intellectual Disabilities in Korea

Meta-Analysis of Single Subject Design Studies on Positive Behavior Support for Students with Intellectual Disabilities in Korea

Adding Practical Tools to Our Toolbox: Introduction to the Special Issue on Quantitative Methodologies

The most recent special issue in the Journal of Pediatric Psychology devoted to methodologies was published more than a decade ago (Noll, 2002). Several articles in that issue focused explicitly on quantitative methodologies. These articles were well-received by and influential within the specific discipline of pediatric psychology and the broader academic community (Aylward, Roberts, Colombo, & Steele, 2008). Owing to, in no small part, the 2002 special issue (Noll, 2002), the field of Pediatric Psychology has continued to mature with regard to methodological and statistical sophistication. Since the 2002 special issue, several important articles on quantitative methodologies were published in the Journal of Pediatric Psychology. These articles include practical coverage of topics such as growth curve modeling (Delucia & Pitts, 2006), analysis of count data (Karazsia & van Dulmen, 2008), effect sizes (Durlak, 2009), structural equation modeling (Nelson, Aylward, & Steele, 2008), and time-window sequential analysis (MacLarenChorney, Garcia, Berlin, Bakeman, & Kain, 2010). This special issue can be viewed as a supplement to such works. Another sign of the field embracing quantitative methods is the recently formed PRISM Special Interest Group, whose members have interests in Pediatric Research and Innovative Statistical Methodologies (Karazsia & Berlin, 2013). As part of our roles as PRISM SIG Co-Chairs, we believed it was time for another issue focused on accessible introductions to quantitative methods that have relevance to pediatric psychologists. With this in mind, our charges to authors in this issue were as follows: (a) write articles as a practical resource or guide, using straightforward language that will promote adoption of techniques by applied researchers; (b) include practical illustrations of methods, preferably with realworld data; and (c) include annotated syntax where appropriate to supplement the illustration. Invited authors for this issue not only answered this call, but they went above and beyond to present complex topics in ways that will resonate with pediatric scholars. The enthusiasm that authors brought to their work is illustrated in the titles. Who, other than Todd Little, would title an article about missing data ‘‘On the Joys of Missing data . . . ’’ (emphasis added; Little, Jorgensen, Lang, & Moore, 2014). While many scholars may dread the issue of missing data, Little, Jorgensen, Lang, and Moore (2014) illustrate proactive methodological strategies that can minimize or prevent the problem when considered before data collection commences. Another example is Eric Youngstrom’s calling the field to ‘‘ROC’’ (Receiver Operator Characteristic) with him (Youngstrom, 2014, ‘‘We are Ready to ROC’’). In his coverage of ROC analyses, Youngstrom (2014) illustrates the intricate relations between real-world issues faced by practicing clinicians, the questions researchers ask, and the quantitative methods that can help answer those questions and yield clinically relevant results. Two articles in this issue serve as complements to recent calls within the field for more single-subject studies (e.g., Rapoff, 2010) by introducing quantitative approaches to analyzing data from such designs (Cohen, Feinstein, Masuda, & Vowles, 2014; Cushing, 2014). These articles also highlight the relevance of pediatric research within real-world clinical practice settings. Cohen, Feinstein, Masuda, and Vowles (2014) wrestle with the fact that

Evaluating the Evidence Base of Performance Feedback in Preservice Special Education Teacher Training

Performance feedback is commonly used during field experiences to improve desired teaching behaviors in preservice teachers. The authors identify eight single-subject studies examining the effects of performance feedback in preservice teachers to determine the evidence base for this practice. These eight studies are reviewed using quality indicators specific to single subject. Positive findings are shown across seven of the eight studies. Targeted behaviors showing the most change are those focused on implementation fidelity of evidence-based instructional strategies. Teacher-specific behaviors do improve after receiving performance feedback. However, the change in these behaviors was not consistent across all studies. Five studies met all rigorous standards of quality research and surpass additional requirements pertaining to evaluating single-subject research. The authors conclude that performance feedback is an evidence-based practice when used to increase implementation fidelity of instructional practices. Implications to the field of special education teacher preparation are discussed.

Motivation: Origins of the Extrinsic/Intrinsic Debate

For over three decades cognitive researchers have studied the overjustification effect, indicating that positively reinforcing behaviors that are intrinsically motivated decreases such behaviors. As a result, some in education advocate that positive reinforcement be limited in educational settings. These studies are reviewed as well as several single-subject studies on the effects of extrinsically reinforcing intrinsically motivated behaviors. While group studies often detect an overjustification effect, it is short-lived and does not occur when positive reinforcement is implemented correctly. Positive reinforcement is a necessary component during the acquisition and maintenance phases of learning.

Science Instruction for Students With Emotional and Behavioral Disorders

This review examined classroom science instruction for students with emotional and behavioral disorders (EBD). A total of 11 group and single-subject studies were analyzed. Across all group studies, a conservatively calculated mean effect size of .471 was obtained indicating the interventions as a whole had at least a small to moderate impact on students’ with EBD achievement. Findings were further analyzed by student characteristics, intervention type, dependent measures utilized, and study variables. A significant result of these subanalyses indicates that while additional research is needed, students with EBD may benefit from inquiry approaches provided the method implemented includes enough structure to ensure student engagement. Results also suggest that mnemonic instruction is highly effective at increasing students’ with EBD knowledge and retention of science facts.

Bias Corrections for Standardized Effect Size Estimates Used With Single-Subject Experimental Designs

A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect sizes are adjusted using Hedges’ small sample bias correction. Next, the within-subject standard deviation is estimated by a 2-level model per study or by using a regression model with the subjects identified using dummy predictor variables. The effect sizes are corrected using an iterative raw data parametric bootstrap procedure. The results indicate that the first and last approach succeed in reducing the bias of the fixed effects estimates. Given the difference in complexity, we recommend the first approach.

Improving Treatment Plan Implementation in Schools: A Meta-analysis of Single Subject Design Studies

Twenty-nine peer-reviewed journal articles that analyzed intervention implementation in schools using single-case experimental designs were meta-analyzed. These studies reported 171 separate data paths and provided 3,991 data points. The meta-analysis was accomplished by fitting data extracted from graphs in mixed linear growth models. This analytic approach was adopted to provide a model whose assumptions were met and could model both level and trend. The extent to which interventions were implemented as planned in baseline was low with a downward trend. Performance feedback, performance feedback augmented with additional procedures, and self-monitoring with environmental supports were found to be highly effective for improving intervention implementation. Follow-up meetings without review of implementation data were ineffective. Maintenance data were positive across studies. Implications of the results for future research and practice are discussed.

Efficacy of Point-of-View Video Modeling

Point-of-view video modeling (POV), a variation of video-based modeling interventions, involves creating a video exemplar from a first-person perspective. The advantage is a significant reduction in extraneous stimuli, as well as increased efficiency in production. However, the lack of systematic analysis to evaluate differential impact on targeted outcomes for individuals with disabilities limits the identification of the population for whom POV is most appropriate, as well as the most efficacious implementation procedure. Through meta-analysis of single-subject studies using POV to improve targeted outcomes, this study identifies differential effects of participant characteristics, implementation procedures, and targeted outcomes. Results of the systematic search reveal that POV has only been implemented with individuals with developmental disabilities or an autism spectrum disorder. Analysis yielded an overall improvement rate difference (IRD) effect size of .78 (83.4% confidence interval [CI] = [.76, .80]). Furthermore, age, disability, and implementation variables moderate outcomes. Areas of future research and implications for practice are discussed.

What is evidence-based behavior analysis?

Although applied behavior analysts often say they engage in evidence-based practice, they express differing views on what constitutes "evidence" and "practice." This article describes a practice as a service offered by a provider to help solve a problem presented by a consumer. Solving most problems (e.g., increasing or decreasing a behavior and maintaining this change) requires multiple intervention procedures (i.e., a package). Single-subject studies are invaluable in investigating individual procedures, but researchers still need to integrate the procedures into a package. The package must be standardized enough for independent providers to replicate yet flexible enough to allow individualization; intervention manuals are the primary technology for achieving this balance. To test whether the package is effective in solving consumers' problems, researchers must evaluate outcomes of the package as a whole, usually in group studies such as randomized controlled trials. From this perspective, establishing an evidence-based practice involves more than analyzing the effects of discrete intervention procedures on behavior; it requires synthesizing information so as to offer thorough solutions to problems. Recognizing the need for synthesis offers behavior analysts many promising opportunities to build on their existing research to increase the quality and quantity of evidence-based practices.

A Review of Technology-Based Interventions to Teach Academic Skills to Students with Autism Spectrum Disorder

A comprehensive review of the literature was conducted for articles published between 1993 and 2012 to determine the degree to which technology-based interventions can be considered an evidence-based practice to teach academic skills to individuals with Autism Spectrum Disorder (ASD). Criteria developed by Horner et al. (Except Child 71:165-178, 2005) and Gersten et al. (Except Child 71:149-164, 2005) were used to determine the quality of single-subject research studies and group experimental research studies respectively. A total of 29 [Corrected] studies met inclusion criteria. Of these studies, only three single-subject studies and no group studies met criteria for quality or acceptable studies. Taken together, the results suggest that practitioners should use caution when teaching academic skills to individuals with ASD using technology-based interventions. Limitations and directions for future research are discussed.

Systematic review of communication partner training in aphasia: Methodological quality

Twenty-three studies identified from a previous systematic review examining the effects of communication partner training on persons with aphasia and their communication partners were evaluated for methodological quality. Two reviewers rated the studies on defined methodological quality criteria relevant to each study design. There were 11 group studies, seven single-subject participant design studies, and five qualitative studies. Quality scores were derived for each study. The mean inter-rater reliability of scores for each study design ranged from 85–93%, with Cohen's Kappa indicating substantial agreement between raters. Methodological quality of research on communication partner training in aphasia was highly varied. Overall, group studies employed the least rigorous methodology as compared to single subject and qualitative research. Only two of 11 group studies complied with more than half of the quality criteria. No group studies reported therapist blinding and only one group study reported participant blinding. Across all types of studies, the criterion of treatment fidelity was most commonly omitted. Failure to explicitly report certain methodological quality criteria may account for low ratings. Using methodological rating scales specific to the type of study design may help improve the methodological quality of aphasia treatment studies, including those on communication partner training.

Reduction of Depressive Symptoms in an Elderly Mexican‐American Female with Type 2 Diabetes Mellitus: A Single‐Subject Study

The purpose of this study was to determine if occupation-based activities improve diabetes self-management and reduce depressive symptoms in an elderly Mexican-American woman with type 2 diabetes mellitus (T2DM). There have been no known studies showing occupational therapy's role in self-care management of T2DM in people with depressive symptoms. The individual in this single-subject research was evaluated using glycosylated haemoglobin blood tests, four self-reported standardized questionnaires, participant reflective logs and clinical observations following an 8-week intervention. The participant improved on all measures, which were sustained 1 month after treatment ended. Clinical implications highlight a new role for occupational therapists providing early intervention in people with diabetes and depression for secondary prevention of complications of uncontrolled diabetes. Research suggestions include multiple single-subject studies showing occupational therapy contributions.

The effects of mindfulness-based treatments for aggression: A critical review

Recently, there has been significant growth in the empirical literature on mindfulness and mindfulness-based treatments (MBTs). The purpose of the current review was to critically examine and critique eleven studies evaluating MBTs for reducing aggressive behaviors. Articles were divided based on design (i.e., group design vs. single subject). This review highlighted evidence supporting the efficacy of the use of mindfulness-based treatments in individuals with aggressive behavior problems. Many of the group studies had weak designs, limiting the validity of the stated results. Results from the single-subject studies were more promising, providing strong support for the use of MBTs in reducing aggression. However, despite recent advances in the use of MBTs with individuals with aggression problems, questions remain unanswered. Finally, suggestions for future research are made to improve and identify means of evaluating the effectiveness of mindfulness-based treatments in an aggressive population. ► Research on mindfulness-based treatments for reducing aggressive behavior is reviewed. ► A comprehensive overview of the strengths and weaknesses is included. ► Four group studies found limited support, though were significantly flawed. ► Seven single-subject studies displayed consistent reductions in aggressive behaviors. ► Suggestions for future research aimed at improving research are presented.

Existing Research and Future Directions for Self-Regulated Strategy Development With Students With and At Risk for Emotional and Behavioral Disorders

Students with emotional and behavioral disorders (E/BD) have academic deficits that affect their success in school. However, there are few research studies investigating what strategies work best for this population, especially in the area of writing. One promising intervention to support the writing skills of students with and at risk for E/BD is self-regulated strategy development (SRSD). SRSD is a six-stage explicit strategy instruction model that includes procedures for goal setting, self-monitoring, self-instruction, and self-reinforcement and can be generalized to a variety of writing tasks. This article summarizes the existing literature using SRSD with students with and at risk for E/BD, including 3 group design and 11 single-subject studies. Future directions for the field are outlined, including using teachers as interventionists, examining behavioral dependent variables, and conducting investigations within three-tiered models of positive behavioral interventions and supports.

A comparison of two treatments for childhood apraxia of speech: methods and treatment protocol for a parallel group randomised control trial

BackgroundChildhood Apraxia of Speech is an impairment of speech motor planning that manifests as difficulty producing the sounds (articulation) and melody (prosody) of speech. These difficulties may persist through life and are detrimental to academic, social, and vocational development. A number of published single subject and case series studies of speech treatments are available. There are currently no randomised control trials or other well designed group trials available to guide clinical practice.Methods/DesignA parallel group, fixed size randomised control trial will be conducted in Sydney, Australia to determine the efficacy of two treatments for Childhood Apraxia of Speech: 1) Rapid Syllable Transition Treatment and the 2) Nuffield Dyspraxia Programme – Third edition. Eligible children will be English speaking, aged 4–12 years with a diagnosis of suspected CAS, normal or adjusted hearing and vision, and no comprehension difficulties or other developmental diagnoses. At least 20 children will be randomised to receive one of the two treatments in parallel. Treatments will be delivered by trained and supervised speech pathology clinicians using operationalised manuals. Treatment will be administered in 1-hour sessions, 4 times per week for 3 weeks. The primary outcomes are speech sound and prosodic accuracy on a customised 292 item probe and the Diagnostic Evaluation of Articulation and Phonology inconsistency subtest administered prior to treatment and 1 week, 1 month and 4 months post-treatment. All post assessments will be completed by blinded assessors. Our hypotheses are: 1) treatment effects at 1 week post will be similar for both treatments, 2) maintenance of treatment effects at 1 and 4 months post will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment, and 3) generalisation of treatment effects to untrained related speech behaviours will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment. This protocol was approved by the Human Research Ethics Committee, University of Sydney (#12924).DiscussionThis will be the first randomised control trial to test treatment for CAS. It will be valuable for clinical decision-making and providing evidence-based services for children with CAS.Trial RegistrationAustralian New Zealand Clinical Trials Registry: ACTRN12612000744853