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Semin Speech Lang 2021; 42(03): 177-179
DOI: 10.1055/s-0041-1730987
Preface

Assessment of Communication Disorders: New Frontiers and Challenges

Gerasimos Fergadiotis
1   Speech and Hearing Sciences, Portland State University, Portland, Oregon
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Assessment is a core-skill for speech-language pathologists. According to the Standards for clinical certification developed by the American Speech Language and Hearing Association (ASHA), graduate students in speech-language pathology are expected to learn how to measure constructs of clinical relevance. Such skills are critical for accurate diagnosis and prognosis, response to intervention, and discharge planning. However, despite the importance of assessment, coursework dedicated to psychometrics is rarely part of the standard curriculum in speech-language pathology programs. As a result, future professionals often miss the opportunity to be exposed to modern measurement frameworks and approaches during their training. This has implications for how effectively they can keep up with current advances in the field of psychometrics and how much they may benefit from using and interpreting modern measurement tools.

It is not surprising perhaps then that most assessment tools clinicians have learned to rely on have been relatively stable for decades. The vast majority of currently available tools were developed under a framework known as classical test theory,[1] [2] a psychometric framework whose core procedures were introduced in the field of psychological measurement in the early 1900s by Spearman.[3] [4] [5] Classical test theory has many advantages and thoughtfully designed tools within this framework can support robust clinical conclusions about people with communication disorders.

Yet, powerful modern approaches have been introduced in the field of psychometrics in the past few decades. During the second half of the past century, model-based measurement exemplified by approaches such as item response theory[6] (IRT) provide the dominant method for test and scale development for health outcomes measurement, and also other fields such as large-scale educational measurement. Further, these approaches have become increasingly integrated into the larger context of models for behavioral and social data. Model-based measurement has gained prominence and become the mainstream as a theoretical psychometric framework because the underlying theoretical assumptions are more realistic and because the potential to solve practical testing problems is greater.

This issue represents the collection of six papers that highlight measurement tools that have been developed within modern model-based psychometric frameworks. The goal is to provide clinicians with an introduction to the underlying theory of the approaches, and then highlight how modern psychometrics can allow us to tackle practical challenges faced by clinicians, policy makers, and people with communication disorders.

In the first paper, Fergadiotis and his colleagues[7] focus on the assessment of anomia severity in people with aphasia. First, they discuss the challenges inherent to confrontation naming tests that are currently available. Then, they present key concepts and advantages of IRT and contrast them with classical test theory. The primary emphasis of the paper is on the ability of IRT to create flexible and efficient tests that yield precise measurements of anomia severity using computer adaptive algorithms. Then, they highlight how such a test can be used to address real-life practical challenges such as reducing testing burden for patients and clinicians, obtaining reliable results despite administering only a subset of items from a given test, and assessing patients more than once without exposing patients to the same items multiple times.

Then, the paper from Cohen, Lanzi, and Boulton[8] introduces patient-reported outcome measures, which are tools that are intended to capture outcomes from the patient's perspective. Patient-reported outcomes are critical in patient-centered, evidence-based practice in the field of communication sciences and disorders. The authors focus primarily on tools that have been developed by the National Institutes of Health using IRT for the assessment of people with a variety of neurological disorders including stroke, Parkinson's disease, and traumatic brain injury. The authors provide implementation information about gaining access, administering, scoring, and interpreting patient-reported outcome measures for patients with communication disorders. In addition, they provide a thorough discussion with practical recommendations on various topics including on the type and extent of communication support that is appropriate, and on how to evaluate whether a patient's perspective of their health status has changed as a function of the clinician's services.

The papers from Hula and Doyle[9] and Baylor, Eadie, and Yorkston[10] continue the discussion on IRT-based patient reported outcome measures but are focused on tools that have been developed specifically for people with communication disorders. First, Hula and Doyle provide an overview of the Aphasia Communication Outcome Measure, a tool that is designed to capture communicative functioning outcomes from the perspective of persons with stroke-induced aphasia. The authors discuss its initial development, evidence supporting its validity as a measure of patient-reported communication functioning for this clinical population, and current recommendations for interpreting change scores. Then, Baylor and her colleagues present the Communicative Participation Item Bank, a tool that is intended to capture communicative participation restrictions and is designed to be used for patients with different communication disorders due to pathologies including stroke, Parkinson's Disease, or cancer.

In the fifth paper of this issue, Evans, Quique, and Boulton[11] focus on the trade-off between performance accuracy and processing speed in people with aphasia. First, the authors present a clinical rationale for the importance of considering speed-accuracy processing relationships in aphasia rehabilitation. Then, they describe two mathematical models that can be used to estimate the optimal response time cutoffs for individual people with aphasia (i.e., the cutoff where additional time is unlikely to lead to a correct response). Finally, they conclude with recommendations regarding how to conceptualize, identify, and potentially address maladaptive speed-accuracy tradeoffs in the clinic.

In the final paper, Walker[12] makes the case for multidimensional assessment of anomia in people with aphasia. To this end, Walker describes how he combined two classes of successful computational models in a highly innovative manner. Specifically, he used a class of models designed for conceptualizing complex cognitive tasks as a series of simpler binary steps that are either performed accurately or not with some probability. Then, he used IRT to model the probability of performing each cognitive process accurately as a function of the difficulty of a test item and the ability of the respondent. Even though more work may be needed at this time before it can be fully implemented in a clinical setting, this work may represent a glimpse of the future of language assessment of people with communication disorders.

The articles in this issue highlight recent developments in the assessment of people with neurologic communication disorders. One common thread across all papers is the use of empirical, mathematically based models in an effort to lay the foundations for reliable, valid, and efficient assessment. Each article in this issue focuses on challenges that clinicians are faced with on a daily basis; and demonstrate how modern psychometrics provide new ways for addressing these challenges. It is our hope that clinicians will utilize this information to advance their practice and outcomes for people with neurologic communication disorders.



Publication History

Article published online:
14 July 2021

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