Single-case Experimental Design Research Articles

Fine-grained effect sizes.

To make transparent individuals' responses to intervention over time in the systematic review of single-case experimental designs, we developed a method of estimating and graphing fine-grained effect sizes. Fine-grained effect sizes are both case- and time-specific and thus provide more nuanced information than effect size estimates that average effects across time, across cases, or both. We demonstrate the method for estimating fine-grained effect sizes under three different baseline stability assumptions: outcome stability, level stability, and trend stability. We then use the method to graph individual effect trajectories from three single-case experimental design studies that examined the impact of self-management interventions on students identified with autism. We conclude by discussing limitations associated with estimating and graphing fine-grained effect sizes and directions for further development. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Single-case experimental designs: the importance of randomization and replication

Single-case experimental designs: the importance of randomization and replication

School staff delivery of a solution focused intervention to support pupils' behaviour

AbstractA single case experimental design with multiple baselines was employed to explore the relationship between a solution focused intervention delivered by school staff and the externalising behaviour of four primary school pupils. The intervention took place over four to five sessions, which were delivered by non‐specialist school staff with the use of training, supervision, and a manual. Observations of a specific positive behaviour were carried out both before and during the intervention, which were then analysed through visual and statistical analysis. A pre and post intervention questionnaire measure of pupils’ externalising behaviour was collected. For each participant, one videoed session was used to explore the fidelity of the intervention to the manual. Analysis of observations of behaviour showed a significant increase in a specific positive behaviour for three of four participants. A measure of pupils’ externalising behaviour showed a significant reduction for two of the eight questionnaires collected. Video analysis suggested variation of fidelity across participants. This research provides tentative support for specific outcomes from a solution focused intervention, when delivered by non‐psychologists who are provided with appropriate support. It has also been found that non‐specialist school staff practitioners were able to deliver the intervention through applying elements from a manual to have a positive impact on a specific behaviour for three of four participants. There is a need for further high quality research to establish the effectiveness of solution focused interventions when delivered by non‐specialists with the use of consistent intervention and outcome measures.

Grammar intervention using graduated input type variation (GITV) for pre-primary children: A single-case experimental design study

Purpose This study examined the early efficacy of a new theory-driven principle of grammar intervention, graduated input type variation (GITV). Method Three Cantonese-speaking children, aged between 4;01 and 5;10, with oral language difficulties participated in this single baseline within-participant single case experimental study. The children received a total of 300 teaching episodes of the target serial verb construction via focused stimulation and recast over 10 30- to 45-minute sessions. The 30 exemplars of the target included low type variation of the verbs in each of the first five sessions, followed by high type variation in the remaining sessions. Result Visual analysis revealed that all children improved their performance in the target construction but not the control vocabulary in the probes, suggesting a treatment effect. Maintenance of treatment effects was also observed in all children. Positive results in across-behaviour generalisation to the untrained construction were observed in all children. Generalisation to other less structured linguistic contexts and to the narrative retell discourse context was minimal and observed in one child only. Conclusion Preliminary evidence suggested early efficacy of GITV as a principle for grammar intervention. Modifications in the research methodology are recommended for future studies involving children with developmental language disorder.

An Ecological Mobile Momentary Intervention to Support Dynamic Goal Pursuit: Feasibility and Acceptability Study.

Individuals can experience difficulties pursuing their goals amid multiple competing priorities in their environment. Effective goal dynamics require flexible and generalizable pursuit skills. Supporting successful goal pursuit requires a perpetually adapting intervention responsive to internal states. The purpose of this study was to (1) develop a flexible intervention that can adapt to an individual's changing short to medium-term goals and be applied to their daily life and (2) examine the feasibility and acceptability of the just-in-time adaptive intervention for goal pursuit. This study involved 3 iterations to test and systematically enhance all aspects of the intervention. During the pilot phase, 73 participants engaged in an ecological momentary assessment (EMA) over 1 month. After week 1, they attended an intervention training session and received just-in-time intervention prompts during the following 3 weeks. The training employed the Capability, Opportunity, Motivation, and Behavior (COM-B) framework for goal setting, along with mental contrasting with implementation intentions (MCII). Subsequent prompts, triggered by variability in goal pursuit, guided the participants to engage in MCII in relation to their current goal. We evaluated feasibility and acceptability, efficacy, and individual change processes by combining intensive (single-case experimental design) and extensive methods. The results suggest that the digital intervention was feasible and acceptable to participants. Compliance with the intervention was high (n=63, 86%). The participants endorsed high acceptability ratings relating to both the study procedures and the intervention. All participants (N=73, 100%) demonstrated significant improvements in goal pursuit with an average difference of 0.495 units in the outcome (P<.001). The results of the dynamic network modeling suggest that self-monitoring behavior (EMA) and implementing the MCII strategy may aid in goal reprioritization, where goal pursuit itself is a driver of further goal pursuit. This pilot study demonstrated the feasibility and acceptability of a just-in-time adaptive intervention among a nonclinical adult sample. This intervention used self-monitoring of behavior, the COM-B framework, and MCII strategies to improve dynamic goal pursuit. It was delivered via an Ecological Momentary Intervention (EMI) procedure. Future research should consider the utility of this approach as an additional intervention element within psychological interventions to improve goal pursuit. Sustaining goal pursuit throughout interventions is central to their effectiveness and warrants further evaluation.

The efficacy of multimodal physiotherapy and usual care in chronic whiplash-associated disorders with facet-mediated pain undergoing platelet rich plasma (PRP) treatment: a series of single case experimental designs (SCEDs)

Purpose Chronic whiplash-associated disorders (WAD) is a heterogeneous condition with limited effective treatment options available. This study evaluated the efficacy of multimodal physiotherapy and usual care in chronic WAD with facet-mediated pain receiving platelet-rich plasma (PRP) injections to determine if pain interference and confidence completing activities in the presence of neck pain could be improved. Materials and methods A multiple-baseline, single-case experimental design was used to evaluate the 6-week effect of physiotherapy or usual care in two groups of three participants each. Results All six participants demonstrated a significant reduction in pain interference, and three participants showed improved confidence to perform daily activities when in pain. Weighted Tau-U demonstrated a significant reduction of pain interference with large to very large effect sizes (> 0.75) for both interventions in all participants irrespective of treatment allocation with no significant group difference demonstrated. Similar effects were demonstrated for the confidence to perform daily activities with neck pain (ES > 0.46), although this was only evident in three participants (two PT and one UC). Generalisation measures also showed improvements in pain and disability, psychological and quality of life outcomes. No adverse events were reported. Conclusions Both physiotherapy and usual care demonstrated improvements in pain interference and confidence to perform activities of daily living with neck pain in people with chronic WAD following cervical facet joint PRP. Trial Registration The trial was registered with ClinicalTrials.gov (Protocol Number: NCT03949959).

Examining Model Similarity for Exercise Self-Efficacy among Adults Recovering from a Stroke: A Community-Based Exercise Program

We used a single-case experimental research design to examine the effect of modelling (peer versus non-peer) on exercise self-efficacy in stroke survivors who participated in a community-based exercise program. Data were obtained using an ABCA design: (A1) no model/baseline 1 (3 weeks); (B) peer model (6 weeks); (C) non-peer model (6 weeks); and (A2) no model/baseline 2 (3 weeks). Four participants completed self-efficacy questionnaires after each weekly session. Overall, participants reported higher exercise self-efficacy in the model conditions (Cohen’s d range from −0.37 to 4.22), with ratings appearing highest for the non-peer model. Modelling in general may help stroke survivors increase their exercise self-efficacy. Lastly, we provide our reflections on the pragmatics of completing a study within a community setting.

Efficacy of an Intensive Exposure Intervention for Individuals With Persistent Concussion Symptoms Following Concussion: A Concurrent Multiple Baseline Single-Case Experimental Design (SCED) Study.

After a concussion, 1 in 3 patients report persistent symptoms and experience long-term consequences interfering with daily functioning, known as persistent concussion symptoms (PCS). Evidence suggests PCS is (partly) maintained by anxious thoughts about brain functioning, recovery, and experienced symptoms, leading to avoidance behaviors, which may prevent patients from meeting life demands. We aimed to investigate the efficacy of a newly developed intensive exposure intervention for individuals with PCS after concussion aimed to tackle avoidance behavior. Participants took part in the intervention at the Maastricht University faculty. Four participants who experienced PCS after concussion partook in the exploratory study. Participants' age ranged between 20 and 32 (mean = 26.5, SD = 5.9) years, with an average length of time after the concussion of 9.8 months. A concurrent multiple-baseline single-case design was conducted. The baseline period (A phase) length was randomly determined across participants (3, 4, 5, or 6 weeks). The exposure intervention (B phase) was conducted by psychologists over a 4-week period and consisted of 3 stages: exploration (2 sessions), active exposure (12 sessions conducted over 1 week), and 2 booster sessions. Participants answered daily questions on a visual analog scale related to symptom experience, satisfaction with daily functioning, and degree of avoidance of feared activities. Additional outcomes included symptom severity, catastrophizing, fear of mental activity, anxiety, depression, and societal participation. Tau-U yielded significant effects (P < .05) for all participants on all measures when comparing baseline and intervention phases. The pooled standardized mean difference was high for all measures (symptom experience = 0.93, satisfaction of daily functioning = 1.86, and activity avoidance = -2.05). The results show efficacy of the newly developed intensive exposure treatment for PCS after concussion, which is based on the fear avoidance model. Replication in a larger heterogeneous sample is warranted and needed.

Acceptability and Feasibility of the Telehealth Bariatric Behavioral Intervention to Increase Physical Activity Before Bariatric Surgery: A Single-Case Experimental Study (Part I).

Physical activity (PA) can play an important role in optimizing metabolic/bariatric surgery (MBS) outcomes. However, many MBS patients have difficulty increasing PA, necessitating the development of theory-driven counseling interventions. This study aimed to (1) assess the feasibility and acceptability of the TELEhealth BARIatric behavioral intervention (TELE-BariACTIV) trial protocol/methods and intervention, which was designed to increase moderate-to-vigorous intensity physical activity (MVPA) in adults awaiting MBS and (2) estimate the effect of the intervention on MVPA. This trial used a repeated single-case experimental design. Twelve insufficiently active adults awaiting MBS received 6 weekly 45-min PA videoconferencing counseling sessions. Feasibility and acceptability data (i.e., refusal, recruitment, retention, attendance, and attrition rates) were tracked and collected via online surveys, and interviews. MVPA was assessed via accelerometry pre-, during, and post-intervention. Among the 24 patients referred to the research team; five declined to participate (refusal rate = 20.8%) and seven were ineligible or unreachable. The recruitment rate was 1.2 participants per month between 2021-09 and 2022-07. One participant withdrew during the baseline phase, and one after the intervention (retention rate = 83.3%). No participant dropouts occurred during the intervention and 98.6% of sessions were completed. Participants' anticipated and retrospective acceptability of the intervention was 3.2/4 (IQR, 0.5) and 3.0/4 (IQR, 0.2), respectively. There was a statistically significant increase in MVPA [Tau-U = 0.32(0.11; 0.51)] from pre- to post-intervention. Despite a low recruitment rate, which could be explained by circumstances (COVID-19 pandemic), results support feasibility, acceptability, and preliminary efficacy of the TELE-Bari-ACTIV intervention for increasing MVPA in patients awaiting MBS.

Leveraging Single-Case Experimental Designs to Promote Personalized Psychological Treatment: Step-by-Step Implementation Protocol with Stakeholder Involvement of an Outpatient Clinic for Personalized Psychotherapy.

Our objective is to implement a single-case experimental design (SCED) infrastructure in combination with experience-sampling methods (ESM) into the standard diagnostic procedure of a German outpatient research and training clinic. Building on the idea of routine outcome monitoring, the SCED infrastructure introduces intensive longitudinal data collection, individual effectiveness measures, and the opportunity for systematic manipulation to push personalization efforts further. It aims to empower psychotherapists and patients to evaluate their own treatment (idiographic perspective) and to enable researchers to analyze open questions of personalized psychotherapy (nomothetic perspective). Organized around the principles of agile research, we plan to develop, implement, and evaluate the SCED infrastructure in six successive studies with continuous stakeholder involvement: In the project development phase, the business model for the SCED infrastructure is developed that describes its vision in consideration of the context (Study 1). Also, the infrastructure's prototype is specified, encompassing the SCED procedure, ESM protocol, and ESM survey (Study 2 and 3). During the optimization phase, feasibility and acceptability are tested and the infrastructure is adapted accordingly (Study 4). The evaluation phase includes a pilot implementation study to assess implementation outcomes (Study 5), followed by actual implementation using a within-institution A-B design (Study 6). The sustainability phase involves continuous monitoring and improvement. We discuss to what extent the generated data could be used to address current questions of personalized psychotherapy research. Anticipated barriers and limitations during the implementation processes are outlined.

Telerehabilitation with Verb Network Strengthening Treatment (VNeST) in two participants with mild-to-moderate and moderate-to-severe aphasia: A single-case experimental design study

ABSTRACT Background Verb Network Strengthening Treatment (VNeST) is a verb-centred aphasia treatment that targets the semantic relationships between a verb (e.g., dig) and related content words (e.g., gardener, hole), aiming to promote word retrieval and sentence production in aphasia. Previous research shows promising results of VNeST in several participants. Aims This study investigates the effects of VNeST through telerehabilitation on word retrieval and sentence production with treated and semantically related untreated verbs, as well as the possible generalisation to confrontation naming and connected speech. Further, functional communication, communicative participation, health-related quality of life and client satisfaction are explored. Methods and Procedures A single-case experimental design study with multiple baselines was conducted with two participants with stroke-induced mild-to-moderate Broca’s aphasia or moderate-to-severe Wernicke’s aphasia who received VNeST through telerehabilitation. Percentage of non-overlapping data, Baseline Corrected Tau and d-index effect size were used to measure improvement in word retrieval and sentence production elicited through video-clip stimuli. The study is registered with ClinicTrials.gov, number NCT05152979. Outcomes and Results The participant with Wernicke’s aphasia improved in word retrieval in sentences with trained and untrained verbs and showed some – albeit limited – generalisation to confrontation naming of nouns and verbs. The participant with Broca’s aphasia withdrew after half of the planned dosage, as he did not consider VNeST suitable for his needs. He did not improve in word retrieval or sentence production. Conclusions VNeST shows promise when it comes to improving word retrieval in trained and semantically related untrained stimuli in moderate-to-severe Wernicke’s aphasia. This study adds to the existing literature by showing potential improvement in VNeST through telerehabilitation.

Impact of a Pilates intervention on physical function in children with generalised joint hypermobility and chronic musculoskeletal pain: A single-case experimental design

AimTo assess the impact of a Physiotherapist-led Pilates Intervention for school aged children with Generalised Joint Hypermobility (GJH) on pain, physical function and Health Related Quality of Life (HRQoL). MethodsThree children aged 8–12 years with GJH participated in an 8 week Physiotherapist-led Pilates Intervention within a single-case experimental design (multiple baseline design). Repeated measures were collected during baseline, intervention, withdrawal and follow-up, for: (i) pain, (ii) physical function as measured by muscle strength, postural control, fatigue and activity levels and (iii) HRQoL. ResultsWithin the intervention phase, two children showed reduced fatigue and one child improved in muscle group strength of hip abduction (gluteus medius) and scapula adduction/rotation (rhomboideus major/minor) and HRQoL. No improvements were seen in pain or postural control. Within the early withdrawal phase all children showed improved strength for at least two muscle groups and one child showed reduced fatigue, pain (worst in last week) and improved postural control (functional reach lateral). ConclusionsPilates may provide an effective intervention for children with GJH to reduce fatigue and improve muscle strength and HRQoL. Limited conclusions can be made regarding pain and postural control. Further research with a longer Pilates duration is needed to confirm the dose and benefits for this population.

Evaluating the impact of movement tracking feedback on engagement with home exercise programmes of children with cerebral palsy using a new therapy app: a protocol for a mixed-methods single-case experimental design with alternating treatments

IntroductionChildren with cerebral palsy (CP) are prescribed home exercise programmes (HEPs) to increase the frequency of movement practice, yet adherence to HEPs can be low. This paper outlines the protocol...

Assessing the Effectiveness of STAPP@Work, a Self-Management Mobile App, in Reducing Work Stress and Preventing Burnout: Single-Case Experimental Design Study.

Work-related stress and burnout remain common problems among employees, leading to impaired health and higher absenteeism. The use of mobile health apps to promote well-being has grown substantially; however, the impact of such apps on reducing stress and preventing burnout is limited. This study aims to assess the effectiveness of STAPP@Work, a mobile-based stress management intervention, on perceived stress, coping self-efficacy, and the level of burnout among mental health employees. The study used a single-case experimental design to examine the use of STAPP@Work among mental health employees without a known diagnosis of burnout (N=63). Participants used the app for 1 week per month repeatedly for a period of 6 months. Using a reversal design, the participants used the app 6 times to assess replicated immediate (1 week after use) and lasting (3 weeks after use) effects. The Perceived Stress Scale, the Coping Self-Efficacy Scale, and the Burnout Assessment Tool were used to measure the outcomes. Linear mixed models were used to analyze the data. After 6 months of app use for 1 week per month, the participants showed a statistically significant decrease in perceived stress (b=-0.38, 95% CI -0.67 to -0.09; P=.01; Cohen d=0.50) and burnout symptoms (b=-0.31, 95% CI -0.51 to -0.12; P=.002; Cohen d=0.63) as well as a statistically significant improvement in problem-focused coping self-efficacy (b=0.42, 95% CI 0-0.85; P=.049; Cohen d=0.42). Long-term use of the app provided consistent reductions in burnout symptoms over time, including in the level of exhaustion and emotional impairment. The use of an app-based stress management intervention has been shown to reduce burnout symptoms and enhance coping self-efficacy among mental health workers. Prevention of burnout and minimization of work-related stress are of utmost importance to protect employee health and reduce absenteeism.

A Comparison of Single-Case Effect Measures Using Check-In Check-Out Data.

There are numerous effect measures researchers can select when conducting a meta-analysis of single-case experimental design research. These effect measures model different characteristics of the data, so it is possible that a researcher's choice of an effect measure could lead to different conclusions about the same intervention. The current study investigated the impact of effect measure selection on conclusions about the effectiveness of check-in check-out (CICO), a commonly used intervention within School-Wide Positive Behavior Interventions and Supports. Using a multilevel meta-analysis of seven different effect measures across 95 cases in 22 studies, findings suggested that all effect measures indicated statistically significant results of CICO in improving student behavior. However, the magnitude of the effects varied when comparing the results to interpretive guidelines, suggesting that the selection of effect measures may impact conclusions regarding the extent to which an intervention is effective. Implications, limitations, and future directions are discussed.

Multilevel modeling in single-case studies with zero-inflated and overdispersed count data.

Count outcomes are frequently encountered in single-case experimental designs (SCEDs). Generalized linear mixed models (GLMMs) have shown promise in handling overdispersed count data. However, the presence of excessive zeros in the baseline phase of SCEDs introduces a more complex issue known as zero-inflation, often overlooked by researchers. This study aimed to deal with zero-inflated and overdispersed count data within a multiple-baseline design (MBD) in single-case studies. It examined the performance of various GLMMs (Poisson, negative binomial [NB], zero-inflated Poisson [ZIP], and zero-inflated negative binomial [ZINB] models) in estimating treatment effects and generating inferential statistics. Additionally, a real example was used to demonstrate the analysis of zero-inflated and overdispersed count data. The simulation results indicated that the ZINB model provided accurate estimates for treatment effects, while the other three models yielded biased estimates. The inferential statistics obtained from the ZINB model were reliable when the baseline rate was low. However, when the data were overdispersed but not zero-inflated, both the ZINB and ZIP models exhibited poor performance in accurately estimating treatment effects. These findings contribute to our understanding of using GLMMs to handle zero-inflated and overdispersed count data in SCEDs. The implications, limitations, and future research directions are also discussed.

A Description of Missing Data in Single-Case Experimental Designs Studies and an Evaluation of Single Imputation Methods.

Missing data is inevitable in single-case experimental designs (SCEDs) studies due to repeated measures over a period of time. Despite this fact, SCEDs implementers such as researchers, teachers, clinicians, and school psychologists usually ignore missing data in their studies. Performing analyses without considering missing data in an intervention study using SCEDs or a meta-analysis study including SCEDs studies in a topic can lead to biased results and affect the validity of individual or overall results. In addition, missingness can undermine the generalizability of SCEDs studies. Considering these drawbacks, this study aims to give descriptive and advisory information to SCEDs practitioners and researchers about missing data in single-case data. To accomplish this task, the study presents information about missing data mechanisms, item level and unit level missing data, planned missing data designs, drawbacks of ignoring missing data in SCEDs, and missing data handling methods. Since single imputation methods among missing data handling methods do not require complicated statistical knowledge, are easy to use, and hence are more likely to be used by practitioners and researchers, the present study evaluates single imputation methods in terms of intervention effect sizes and missing data rates by using a real and hypothetical data sample. This study encourages SCEDs implementers, and also meta-analysts to use some of the single imputation methods to increase the generalizability and validity of the study results in case they encounter missing data in their studies.

Islamic Cognitive Behavior Therapy to increase self-efficacy

The problem of drug abuse is getting more complex day by day. The reasons for teenagers using drugs are curiosity or experimentation and seeking to have fun. Part of the appeal of using drugs is the assumption that drugs will increase self-efficacy (belief in one's own ability to complete a task), either directly or indirectly). Islamic Cognitive Behavior Therapy (ICBT) modifies behavior and changes cognitive processes when faced with temptation or when facing life's problems that they have to live through when they are free from drugs. This study used a qualitative approach with single case experimental designs. The research design used in this study is the A-B-A design. Phase A is where the client's condition is without treatment and the conditions experienced by the client are analyzed or the baseline phase. Phase B is the condition where the treatment/intervention ICBT is given, and the last phase A is the condition where the researcher sees the effect of the intervention that has been carried out on the client which is also called the follow-up phase. This research found that applying Islamic Cognitive restructuring therapy reduced negative thinking so that the client can prioritize quality life. The implementation of ICBT makes the client aware of its importance and improves life free from drug addiction

Combining executive function training and anomia therapy in chronic post-stroke aphasia: A preliminary study of multidimensional effects

Purpose The influential relationship between executive functioning and aphasia rehabilitation outcomes has been addressed in a number of studies, but few have studied the effect of adding executive function training to linguistic therapies. The present study aimed to measure the effects of combining, within therapy sessions, executive function training and anomia therapy on naming and discourse abilities in people with chronic aphasia. Method A single-case experimental design with multiple baselines across participants was used. Four persons with chronic post-stroke aphasia received 12 sessions of a tailored treatment combining executive function training and semantic feature analysis (SFA) therapy. Naming accuracy of treated items was examined over the course of the treatment while control naming scores of untreated items and discourse measures were collected pre-treatment, immediately post-treatment, and 4 weeks post-treatment, in order to investigate the multidimensional effects of the treatment and their maintenance. Result Naming skills improved in all participants for treated and untreated items, were maintained over time, and were accompanied by improved discourse abilities. Visual and statistical analyses showed a significant treatment effect for naming skills in three out of the four participants. Conclusion A combination of executive function training and SFA treatment in people with chronic aphasia may improve both naming skills and discourse efficiency. Further studies are needed to substantiate these promising preliminary results.

The unified protocol for transdiagnostic treatment of emotional disorders for misophonia: a pilot trial exploring acceptability and efficacy.

Misophonia is a recently defined disorder characterized by distressing responses to everyday sounds, such as chewing or sniffling. Individuals with misophonia experience significant functional impairment but have limited options for evidenced-based behavioral treatment. To address this gap in the literature, the current pilot trial explored the acceptability and efficacy of a transdiagnostic cognitive-behavioral approach to treating symptoms of misophonia. This trial was conducted in two studies: In Study 1, the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP) was delivered to eight patients in order to receive feedback to guide revisions to the treatment to suit this population. In Study 2, ten patients received the revised UP treatment to explore its acceptability and preliminary efficacy. This study used a single-case experimental design with multiple baselines, randomizing patients to either a 2-week baseline or 4-week baseline prior to the 16 weeks of treatment, followed by four weeks of follow-up. The findings from these studies suggested that patients found both the original and adapted versions of the UP to be acceptable and taught them skills for how to manage their misophonia symptoms. Importantly, the findings also suggested that the UP can help remediate symptoms of misophonia, particularly the emotional and behavioral responses. These findings provide preliminary evidence that this transdiagnostic treatment for emotional disorders can improve symptoms of misophonia in adults.