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Evidence Maps

What are Evidence Maps?

An Evidence Map is a searchable online tool designed to assist clinicians with making evidence-based decisions. Each Evidence Map highlights the importance of the three components of evidence-based practice—external scientific evidence, clinical expertise, and client perspectives—and provides the latest information related to the assessment, treatment, and service delivery for various communication disorders.

How are Evidence Maps used by clinicians?

Because speech-language pathologists and audiologists often do not have time to stay up-to-date with the latest clinical research, they must look to available resources that synthesize that research. The Evidence Maps provide clinicians with a quick synopsis of guidelines, systematic reviews, and individual client perspective studies pertaining to speech-language pathology and audiology clinical topics.

Types of Evidence Included in Evidence Maps

What is external scientific evidence?

External scientific evidence refers to the results of research that has been conducted in a specific area of treatment, assessment, or service delivery. Although evidence may be obtained from individual studies, only evidence-based guidelines and systematic reviews are included in this section.

What is clinical expertise?

Clinical expertise refers to the experience, education, and clinical skills of the treating clinician and/or clinical experts. Consensus-based statements from guidelines and ASHA policy documents are included in this section.

What are client perspectives?

Client perspectives refer to the individual perspective, unique concerns, expectations, and/or values that the client and family bring to the clinical encounter. Unlike the other sections of the Evidence Map, this section includes research from individual research studies, guidelines, and systematic reviews.

Types of Articles Included in Evidence Maps

What are guidelines?

Guidelines are documents developed by a group of experts that include recommendations intended to optimize the delivery of services to a select population under specific clinical circumstances. Guidelines may include recommendations that are evidence-based and/or consensus-based. Evidence-based recommendations are established in consideration of the research literature using a rigorous, unbiased, and transparent process. These recommendations are classified in the Evidence Maps as External Scientific Evidence. Consensus-based recommendations are decided upon by experts in the field and are classified in the Evidence Maps as Clinical Expertise.

What are systematic reviews?

Systematic reviews are documents that provide a comprehensive, unbiased synthesis of the scientific literature on a given topic without making specific recommendations for clinical practice. Specific methods are employed to search for and appraise the quality of the studies included in systematic reviews.

What are client perspective studies?

Any study, regardless of research design, that reports client or caregiver satisfaction or perspectives regarding the outcomes and/or delivery of speech-language pathology or audiology services is placed in the category client perspectives studies.

What are practice policy documents?

ASHA practice policy documents, which are written for and by ASHA members and approved by ASHA governance, contain detailed guidance on the responsibilities, ethics, and scopes of practice for speech-language pathologists and audiologists.

Types of Information Included in Articles in Evidence Maps

What information does ASHA provide about each article?

For each article in an Evidence Map, ASHA provides the citation; type of document (e.g., guideline, review, or study); description of the document, including the population(s) studied; specific assessments/interventions/service delivery considerations addressed; intended target audience; and specific recommendations or conclusions pertaining directly to speech-language pathology or audiology practices. Depending on the type of document, the description may also include levels of evidence or evidence ratings provided by the authors or guideline development group.

What is the difference between a conclusion and a recommendation?

A conclusion summarizes the findings of a systematic review and discusses the interpretation of the findings beyond what is reported statistically. Systematic reviews provide conclusions about the body of scientific evidence and describe the extent to which various assessment, treatment, or service delivery approaches are supported by the evidence, but typically stop short of making specific recommendations for clinical practice. A recommendation states what should or should not be done in clinical practice. Guidelines provide recommendations based on the body of evidence or based on consensus from experts in the field.

What are evidence ratings, and how should I interpret them?

Oftentimes, the guideline development group will provide a hierarchical rating system to highlight the quality of the evidence and the strength of the recommendation provided. The ratings are designed to help clinicians determine how much confidence they can place in a particular recommendation or set of recommendations. A number of rating systems are currently in use, some of which base a recommendation solely on study design whereas others incorporate additional factors, such as quality of the evidence, resource utilization, benefits, and harms. When applicable, the evidence grading scheme and the corresponding descriptors for each rating are provided.

What if I want more information about an included article?

Each article has an accompanying link to more detailed information about the article (i.e., Read ASHA's Article Summary) as well as information needed to access the full document (i.e., Go to Article).

Building Evidence Maps

Where do these articles come from?

ASHA's National Center for Evidence-Based Practice in Communication Disorders (N-CEP) systematically conducts searches and vets all pertinent guidelines, reviews, and client perspective studies before including them in an Evidence Map. All documents are included for informational purposes only, and their inclusion does not imply that ASHA endorses or agrees with any particular conclusions or recommendations.

Does ASHA include primary research from individual studies as external scientific evidence?

Given the frequency with which new research studies become available, it is not feasible to comprehensively identify and review all of the relevant independent articles to present in an Evidence Map. Also, because individual research studies often focus on a narrow sample and specific interventions in a controlled environment, it is not always possible to generalize findings to apply to conditions beyond those of the experiment. Additional studies may be necessary to replicate study results before clinicians can feel confident in applying the research findings. When developing the Evidence Maps, N-CEP relies on guidelines and systematic reviews to initially vet the primary research evidence and formulate conclusions and recommendations for the broader research question of interest.

Does ASHA include all evidence-based guidelines and systematic reviews as external scientific evidence?

Unfortunately, many guidelines are developed with questionable methodological rigor and/or reflect the bias(es) of the authors. Also, many reviews use a narrative format; in order to be considered truly systematic, reviews must use a transparent and reproducible process.

To address these shortcomings, N-CEP applies a specific set of criteria to determine if a document should be included as external scientific evidence. All guidelines must receive an overall rating of Highly Recommended or Recommended with Provisos and meet a minimum threshold for methodological rigor based on the widely adopted framework known as the AGREE framework. N-CEP includes all applicable reviews and provides an appraisal of methodological rigor based on six quality indicators.

What are AGREE ratings?

AGREE, also known as the Appraisal of Guidelines for Research and Evaluation, is a framework consisting of 23 criteria across six domains (e.g., rigor of development, stakeholder involvement) designed to evaluate the applicability, currency, comprehensiveness, and methodological rigor of clinical guidelines. N-CEP staff review and score each guideline based on modified AGREE criteria and categorize the guideline as Highly Recommended, Recommended with Provisos, or Not Recommended based on the AGREE scoring system. Only guidelines rated as Highly Recommended or Recommended with Provisos are included in the Evidence Maps.

What are quality indicator ratings?

Quality indicator ratings are ratings assigned by N-CEP staff to indicate the methodological quality of an included systematic review (e.g., search strategy described in sufficient detail for replication, quality assessments that are reproducible). The ratings are provided so that clinicians can more easily evaluate the quality of the review, including the validity of the findings, as well as make clinical judgments about the applicability of the findings to their clients.

Why are some sections of an Evidence Map empty?

In some cases, no guidelines, evidence-based systematic reviews, or individual studies measuring client satisfaction or perspectives are available for a given treatment, assessment, or service delivery model. ASHA will update empty sections of an Evidence Map as information becomes available.

How often are Evidence Maps updated?

New guidelines, systematic reviews, and individual client perspective studies are published every day. N-CEP intends to keep the Evidence Maps as current as possible and will publish new documents to an existing Evidence Map on an ongoing basis.

What are Future Maps?

A Future Map is a searchable online tool—like an Evidence Map—that covers speech-language pathology and audiology topics that are currently under development. Future Map topics are identified and published on an ongoing basis by N-CEP.

Can I Adapt the Evidence to My Clients?

How can I apply an Evidence Map to my clinical practice?

The first step in applying evidence to a clinical decision is to ask an answerable clinical question. One widely used approach to framing a clinical question is PICO; the acronym stands for

  • Population (P), 
  • Intervention/Assessment (I), 
  • Comparison (C), 
  • Outcome (O).

These are the issues about which you seek answers. Considering these factors gives you a head start in finding evidence that is relevant (applicable to a client) and valid (i.e., the study measured what the researchers intended to measure).

Review the guidelines, systematic reviews, and client perspective studies included in an Evidence Map and consider whether the information provided matches the characteristics and goals of the client being treated. Because there is no magic formula for making evidence-based decisions, clinicians should consider the information included in an Evidence Map along with their own clinical expertise; the individual circumstances and preferences of the client; and the benefits, risks/harms, and costs of assessment and/or treatment to determine the optimal course of service provision.

What if there is no available evidence on a clinical topic?

In some cases, no synthesized research is available for a given assessment, treatment, or service delivery model that might be best aligned with the characteristics of the client and clinical question being asked. Consider how useful available guidelines, systematic reviews, and client satisfaction and perspective studies are from similar populations, settings, and/or interventions and determine whether the evidence can be extrapolated to your client.

Additionally, clinicians can turn to primary research from individual studies to help make treatment decisions. A number of online bibliographic databases are available (e.g., MEDLINE, ERIC) to find primary research on a clinical topic.

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