Effect Sizes in Single-Case Aphasia Studies: A Comparative, Autocorrelation-Oriented Analysis

Reproducibility in Small-N Treatment Research: A Tutorial Using Examples From Aphasiology

PURPOSE

Small-N studies are the dominant study design supporting evidence-based interventions in communication science and disorders, including treatments for aphasia and related disorders. However, there is little guidance for conducting reproducible analyses or selecting appropriate effect sizes in small-N studies, which has implications for scientific review, rigor, and replication. This tutorial aims to (a) demonstrate how to conduct reproducible analyses using effect sizes common to research in aphasia and related disorders and (b) provide a conceptual discussion to improve the reader's understanding of these effect sizes.

METHOD

We provide a tutorial on reproducible analyses of small-N designs in the statistical programming language R using published data from Wambaugh et al. (2017). In addition, we discuss the strengths, weaknesses, reporting requirements, and impact of experimental design decisions on effect sizes common to this body of research.

RESULTS

Reproducible code demonstrates implementation and comparison of within-case standardized mean difference, proportion of maximal gain, tau-U, and frequentist and Bayesian mixed-effects models. Data, code, and an interactive web application are available as a resource for researchers, clinicians, and students.

CONCLUSIONS

Pursuing reproducible research is key to promoting transparency in small-N treatment research. Researchers and clinicians must understand the properties of common effect size measures to make informed decisions in order to select ideal effect size measures and act as informed consumers of small-N studies. Together, a commitment to reproducibility and a keen understanding of effect sizes can improve the scientific rigor and synthesis of the evidence supporting clinical services in aphasiology and in communication sciences and disorders more broadly. Supplemental Material and Open Science Form: https://doi.org/10.23641/asha.21699476.

Conversation as an Outcome of Aphasia Treatment: A Systematic Scoping Review

PURPOSE

Conversation-focused speech-language pathology services are a top priority for people living with aphasia, but little is known about how researchers measure conversation as an outcome of treatment. This scoping review was undertaken to systematically review the evidence regarding the measurement of conversation in aphasia studies and to identify current practices and existing gaps.

METHOD

A systematic literature search was conducted for studies published between January 1995 and September 2019 in multiple electronic databases. Covidence software was used to manage search results, study selection, and data charting processes. Data were extracted from each study and then collated and organized to elucidate the breadth of approaches, tools, or procedures oriented to measuring conversation as an outcome and identify gaps in the existing literature.

RESULTS

The systematic search of the literature resulted in 1,244 studies. A total of 64 studies met inclusion criteria and were included in the review. The review summarizes the various tools and procedures used to measure conversation as an outcome of aphasia intervention, including variations in data collection and analysis procedures. The review also evaluates the quality of conversation measures in terms of psychometric properties and informal measures of validity. There was a total of 211 measures used across the 64 studies.

CONCLUSIONS

While there was no clear measure that was objectively superior, several measures show promise and warrant future exploration. Some of the orientations, conceptualizations, and procedures we have presented can be seen as options that might be included in a future conversation-focused core outcome set.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21514062.

Get in Sync: Active Ingredients and Patient Profiles in Scripted-Sentence Learning in Spanish Speakers With Aphasia

PURPOSE

Script training is a well-established treatment for aphasia, but its evidence comes almost exclusively from monolingual English speakers with aphasia. Furthermore, its active ingredients and profiles of people with aphasia (PWA) that respond to this treatment remain understudied. This study aimed to adapt a scripted-sentence learning protocol to Colombian Spanish speakers with aphasia, investigate speech entrainment (i.e., unison production of sentences) as an active ingredient for scripted-sentence learning, and identify patient profiles associated with better scripted-sentence learning.

METHOD

Fourteen monolingual Spanish speakers with aphasia learned a set of 30 sentences. To examine speech entrainment as an active ingredient for scripted-sentence learning, we investigated whether sentences containing externally added rhythmic cues (involving stress-aligned vs. metronomic rhythmic cues) would result in better scripted-sentence learning compared with control sentences. Learning was measured via postsession probes and analyzed using mixed-effects logistic regression models. The relationship between scripted-sentence learning and baseline language and rhythmic processing measures was also examined.

RESULTS

Significant scripted-sentence learning over time indicated a successful adaptation of a script-training protocol to Spanish. PWA learned significantly more scripted sentences in the rhythmically enhanced conditions compared with the control condition. There were no differences between rhythmically enhanced conditions (stress-aligned vs. metronomic). In terms of patient profiles, it was found that PWA with more severe aphasia demonstrated larger learning gains, but rhythmic processing showed little association with learning estimates.

CONCLUSIONS

To our knowledge, this study provides the first adaptation of a scripted-sentence learning protocol for monolingual Spanish speakers with aphasia, demonstrating cross-linguistic benefits of script training interventions. Highlighting rhythmic features during speech entrainment facilitated scripted-sentence learning in Spanish speakers with aphasia, suggesting that speech entrainment may be an active ingredient for scripted-sentence learning. More severe aphasia was associated with better scripted-sentence learning, suggesting that more severely impaired individuals are likely to benefit most from this treatment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19241847.

Acceptance and commitment therapy for individuals with depressive and anxiety symptoms following acquired brain injury: A non-concurrent multiple baseline design across four cases

Patients with acquired brain injury (ABI) often experience symptoms of anxiety and depression. Until now, evidence-based treatment is scarce. This study aimed to investigate the effectiveness of Acceptance and Commitment Therapy (ACT) for patients with ABI. To evaluate the effect of ACT for people with ABI, a non-concurrent multiple baseline design across four cases was used. Participants were randomly assigned to a baseline period, followed by treatment and then follow-up phases. Anxiety and depressive symptoms were repeatedly measured. During six measurement moments over a year, participants filled in questionnaires measuring anxiety, depression, stress, participation, quality of life, and ACT-related processes. Randomization tests and NAP scores were used to calculate the level of change across phases. Clinically significant change was defined with the Reliable Change Index. Three out of four participants showed medium to large decreases in anxiety and depressive symptoms (NAP = 0.85 till 0.99). Furthermore, participants showed improvements regarding stress, cognitive fusion, and quality of life. There were no improvements regarding psychological flexibility, value-driven behaviour, or social participation. This study shows that ACT is possibly an effective treatment option for people experiencing ABI-related anxiety and depression symptoms. Replication with single case or large scale group studies is needed to confirm these findings.

Individual Hearing Aid Benefit in Real Life Evaluated Using Ecological Momentary Assessment

Ecological momentary assessment (EMA) was used in 24 adults with mild-to-moderate hearing loss who were seeking first hearing-aid (HA) fitting or HA renewal. At two stages in the aural rehabilitation process, just before HA fitting and after an average 3-month HA adjustment period, the participants used a smartphone-based EMA system for 3 to 4 days. A questionnaire app allowed for the description of the environmental context as well as assessments of various hearing-related dimensions and of well-being. In total, 2,042 surveys were collected. The main objectives of the analysis were threefold: First, describing the "auditory reality" of future and experienced HA users; second, examining the effects of HA fitting for individual participants, as well as for the subgroup of first-time HA-users; and third, reviewing whether the EMA data collected in the unaided condition predicted who ultimately decided for or against permanent HA use. The participants reported hearing-related disabilities across the full range of daily listening tasks, but communication events took the largest share. The effect of the HA intervention was small in experienced HA users. Generally, much larger changes and larger interindividual differences were observed in first-time compared with experienced HA users in all hearing-related dimensions. Changes were not correlated with hearing loss or with the duration of the HA adjustment period. EMA data collected in the unaided condition did not predict the cancelation of HA fitting. The study showed that EMA is feasible in a general population of HA candidates for establishing individual and multidimensional profiles of real-life hearing experiences.