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Searching for and Finding Evidence in Augmentative and Alternative Communication (AAC): Navigating a Scattered Literature. Oliver Wendt, MS, Doctoral Candidate Purdue University

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slide1
Searching for and Finding Evidence in Augmentative and Alternative Communication (AAC): Navigating a Scattered Literature

Oliver Wendt, MS, Doctoral Candidate

Purdue University

American Speech-Language Hearing Association, Division 12: Augmentative and Alternative Communication (DAAC), 7th Annual Conference

presentation based on
Presentation based on

Schlosser, R. W., Wendt, O., Angermeier, K. L., & Shetty, M. (2005). Searching for evidence in augmentative and alternative communication: Navigating a scattered literature. Augmentative and alternative communication, 21 (4), 233-255.

what is evidence based practice ebp
What is Evidence-based Practice (EBP)?
  • “Evidence-based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients” (Sackett et al., 1996).
  • “…the integration of best and current research evidence with clinical/educational expertise and relevant stakeholder perspectives to facilitate decisions for assessment and intervention that are deemed effective and efficient for a given direct stakeholder” (Schlosser & Raghavendra, 2003, p. 256)
the ebp process
The EBP Process

1. Developing a well-built question

2. Selecting evidence sources & executing the search strategy

3. Examining and synthesizing the evidence

4. Applying the evidence

5. Evaluating the application of the evidence

6. Disseminating the findings

(Sackett et al., 1996 - Steps 1-5)

the role of the search
The Role of the Search
  • AAC literature is scattered
    • It takes knowledge and skills (K & S)
  • Consequences of an inadequate search
    • Ignore pertinent evidence
      • (Erroneously) conclude that there is no evidence available
    • Over- or underestimate the support for a particular intervention
    • Misinterpret the applicability of the evidence
potential sources of evidence
Potential Sources of Evidence
  • Textbooks
  • Journals
  • Newsletters
  • Databases with pre-filtered evidence
    • "…an individual or group of individuals with expertise in a particular substantive area has reviewed and presented the methodologically strongest data in the field" (Melnyk and Fineout-Overholt, 2002, p. 263, based on Guyatt and Rennie, 2002).
      • Database of Abstracts of Reviews of Effects (DARE)
        • http://www.york.ac.uk/inst/crd/welcome.html
  • General Purpose Databases
    • CINAHL, ERIC, LLBA, MEDLINE, PsycINFO
  • Internet
assumptions continued
Assumptions Continued
  • Locate best & most current evidence first
    • Work down the hierarchy of sources
      • Database of Reviews of Effects (DARE)
      • Cochrane Database of Systematic Reviews
  • Seek out reviews before individual research studies
  • Look for peer-reviewed evidence before non-peer-reviewed evidence
example 1 comparative efficacy
Example 1 - Comparative Efficacy
  • Begin with scenario:
    • A team of practitioners and family members, serving a 6-year old child with developmental disabilities (i.e., severe to profound mental retardation), have deemed it appropriate to introduce manual signing. They are, however, unsure what instructional strategy is most effective and efficient to yield successful expressive use and receptive learning
  • Consider your question:
    • “What instructional strategies are most effective and efficient in yielding expressive signing and receptive speech?”
example 1 continued
Example 1 Continued

3. Extract general keywords/limiters (quality filters) from question

  • Direct extractions
    • Manual signing, signing
    • Developmental disabilities
    • Instruction (treatment, intervention, therapy)
    • Effectiveness
    • Efficiency
    • Expressive use
    • Receptive speech
    • Young children
  • Extrapolations
    • Comparative (treatment) studies
    • Group studies
    • Single-subject experimental designs
example 1 continued17
Example 1 Continued

4. Determine and prioritize appropriate evidence sources:

  • (a) DARE
  • (b) General-purpose databases (prioritize: PsycINFO)
  • (c) Internet (if needed)
example 1 continued28
Example 1 Continued

5. Implement search for reviews - DARE

      • Augmentative communication, alternative communication, assistive technology, sign language, manual sign

6. Examine results (reviews) - DARE

augmentative communication/All fields OR alternative communication/All fields OR assistive technology/All fields - 2 Hits (1-2)

(Record 1)

Promoting generalization and maintenance in augmentative and alternative communication: a meta-analysis of 20 years of effectiveness research.

Schlosser R W, Lee D L. AAC: Augmentative and Alternative Communication 2000; 16(4): 208-226.

(Record 2)

Speech and language therapy to improve the communication skills of children with cerebral palsy.

Pennington L, Goldbart J, Marshall J. Speech and language therapy to improve the communication skills of children with cerebral palsy (Cochrane Review). In: The Cochrane Library, Issue 4, 2004. Chichester, UK: John Wiley & Sons, Ltd

  • sign language/All fields OR manual sign/All fields - No Hits
slide30
How to get the other ones not in database?
    • McDonald, L. (1977). A comparison of three methods of word imitation training with Down’s Syndrome children under six years of age. Unpublished master’s thesis. University of Manitoba, Winnipeg. Canada.
      • ---> AAC Thesis and Dissertations (Lloyd, Koul, & Arvidson, 1993, 1994; Lloyd, Arvidson, & Koul, 1996)
    • Iacono, T., & Parsons, C. (1986). A comparison of techniques in teaching signs to the intellectually disabled using an alternating treatments design. Australian Journal of Human Communication Disorders, 14, 23-34.
      • ----> Handsearch
slide34
What can we glean from this backward process?
    • Sign language
      • Most widely and consistently used KW
      • If not used, other alternatives are
        • Manual communication
        • Communication skills training
    • ( ) Mental retardation
      • is best to capture the population
    • Quality filter:
      • Empirical study (only one without it)
      • “compar*” as a free-text word works for most
slide35
5. Implement search for reviews & 6. Examine Results - PsycINFO

-12 references, but none focused on topic (autism, not treatment focused) ---> refine search

slide36

-3 references, but none focused on topic (autism, not treatment focused)

----> Need to look for individual studies

slide37
5. Implement search for studies - PsycINFO

Add limiters (quality filters)

slide40
revise search (and implement again)

6. Examine the results (studies) - PsycINFO

example 1 lessons
Example 1 Lessons
  • Use the thesaurus to build your search
  • When you found an appropriate reference, check it out in terms of indexing
  • Use synonyms or terms that describe similar concepts
  • Be mindful - terminology changes, but the indexing may not be retro-active
  • Don’t forget the “TX” option
  • Consider to use truncation
  • Trust no one! Indexers are not perfect.
  • “Pearl Growing” can be a beneficial EBP search strategy (if you have a relevant article to start with)
pearl growing
Pearl Growing
  • Pearl Growing involves the following process
    • (1) Find a relevant article;
    • (2) find the terms under which the article is indexed in database-1;
    • (3) find other relevant articles in database-1 by using the index terms in a Building Block query;
    • (4) repeat 2-3 in other databases;
    • (5) repeat 1-4 for other relevant articles; and
    • (6) end when articles retrieved provide diminishing relevance.
an illustration of pearl growing
An Illustration of Pearl Growing
  • Question
    • What strategies are most effective and efficient for introducing manual signs to children with developmental disabilities in terms of expressive signing, and/or expressive natural speech, and/or receptive speech?
  • (1) Our Pearl
    • Clarke, S., Remington, B., and Light, P., 1988, The role of referential speech in sign learning by mentally retarded children: A comparison of total communication and sign-alone training. Journal of Applied Behavior Analysis, 21, 419-426.
slide47
(2) Under which terms is the pearl indexed in database 1 - Medline?
    • Medical Subject Heading terms (italic = most relevant):
      • Child; Child, Preschool; Communication Methods, Total; Comparative Study; Female; Humans; Imitative Behavior; Male; Manual Communication; Mental Retardation/rehabilitation; Rehabilitation; Research Support, Non-U.S. Gov't; Sign Language; and Speech.
    • the “pearl” was not indexed with a particular publication type
      • The MeSH term “comparative study” can serve to filter out studies that involve only one treatment.
    • Checked the MeSH database http://www.nlm.nih.gov/mesh/MBrowser.html to identify other relevant terms to capture this population
      • found “developmental disabilities” and “autistic disorder.”
slide48
(3) find other relevant articles using terms in Medline
    • First goal is to identify reviews:
      • [(communication methods, total OR sign language OR manual communication) AND (mental retardation OR developmental disabilities OR autistic disorder)] using “child,” “human,” and sequentially “meta-analysis,” “review,” & “practice guideline” as limiters.
        • Using “review”- Yield: 9 entries - three were applicable (Bondy & Frost, 1998; Howlin, 1988; Wilken, 1996).
slide49
Second goal is to identify individual studies:
    • [(communication methods, total OR sign language OR manual communication) AND comparative study AND (mental retardation OR developmental disabilities OR autistic disorder) AND speech)] using “child” and “human” as limiters
      • Yield: 3 additional relevant references (Brady & Smouse 1978; Layton 1988; Wells 1981).
      • PT use varied from case report to clinical trial to RCT
    • Repeat search without “speech”
      • Yield: 9 references - 4 were applicable (Barrera & Sulzer-Azaroff 1983; Kahn 1981; Sisson & Barrett 1984; Wherry & Edwards, 1983)
      • PT use varied from none to case report to clinical trials to RCT
      • This variation in quality filters along with the absence of any additional keywords made it unnecessary to conduct more MEDLINE searches.
slide50
(4) repeat steps 2-3 in PsycINFO
    • This pearl is indexed under the following Descriptors:
      • communication skills training, phenylketonuria, sign language, severe mental retardation, and verbal communication
      • Form/Content Type of “empirical study” as a quality filter
      • This provided some valuable keywords (in italics) and one quality filter to start with
      • We supplemented other relevant keywords to better describe the population of developmental disabilities using the thesaurus
    • First goal is to identify reviews:
      • [(DE "Sign Language" or DE "Verbal Communication") and (DE "Communication Skills Training") and (DE "Mental Retardation" or DE "Developmental Disabilities" or DE "Pervasive Developmental Disorders")] using literature review and meta-analysis as quality filters.
        • Yield: No hits
slide51
Second goal is to identify individual studies:
    • As above with limiters: preschool child, school-age child, and adolescent
      • Yield: 7 hits with 6 meeting our relevancy criteria (Bonta & Watters 1983; Braam & Poling 1983; Bucher 1983; Gaines et al., 1988; Light et al., 1990; Remington et al.,1990).
      • All of these hits were indexed under the form/content type of “empirical study” (i.e., a quality filter), just like the “pearl.”
      • An analysis of keywords revealed no viable additional ones and so we abandoned the search for more entries
example 2 speech production
Example 2 - Speech Production
  • 1. Start with scenario
      • Sam is a 4-year old child who was recently diagnosed with autism. He is unable to meet his daily communication needs in his preschool through natural speech. He has recently learned to imitate words such as “mama,” “dada,” “quack-quack,” and “bye-bye.” To date, Sam does not use these words to communicate. His family and the staff at his preschool anticipate many of his needs and consistently respond to his prelinguistic communication behaviors such as touching objects or leading people to objects he wants or activities that he would like to do. Sam’s parents hope that he will eventually speak and be included in a classroom with typically-developing children. Prior to Sam’s diagnosis, his parents were not interested in exploring other forms of communication because they had serious concerns about the impact on Sam’s potential for developing speech. Their current goals for Sam are that he improve his speech and communicate more effectively through whatever means are appropriate and supportive of speech development.
  • 2. Consider your question:
      • His parents want to know, “Which AAC approach(es) best support natural speech production?”
example 2 continued
Example 2 Continued

3. Extract potential keywords/limiters from question

  • Direct extractions
    • Autism
    • Presymbolic (Prelinguistic)
    • Instruction (treatment, intervention, therapy)
    • Augmentative communication, alternative communication
    • Effectiveness/efficiency
    • Preschool children
    • Settings: special education, toward inclusion
    • Speech production
  • Extrapolations
    • Prognosis
    • Comparative (treatment) studies
    • Group studies
    • Single-subject experimental designs
    • Social validation
example 2 continued55
Example 2 Continued

4. Prioritize your search

  • DARE
  • (Conference Proceedings)
  • General-purpose databases
slide56
5. Implement your search - DARE
  • Broaden your search

6. Examine Results

slide57
5. Implement search for reviews - PsycINFO

6. Examine the results (reviews) -PsycINFO

slide59
5. Implement search for reviews - ERIC

6. Examine the results (reviews) - ERIC

slide62
5. Implement search for reviews - Medline
  • First go for meta-analyses

- Broaden to other reviews

slide65
5. Implement search for reviews - CINAHL

6. Examine the results (reviews) - CINAHL

slide66
5. Implement search for reviews -CINAHL

6. Examine the results (reviews) - CINAHL

slide67
5. Implement search for reviews - CINAHL

6.Examine the results (reviews) - CINAHL

searching conference proceedings latest reviews
Searching conference proceedings latest reviews
  • Special issue on speech output:
    • Yielded 1 relevant review
      • Blischak, D. M., Dyson, A. T., & Lombardino, L. J. (2003). Use of speech-generating devices: In support of natural speech. Augmentative and Alternative Communication, 19, 29-35.
  • ISAAC proceedings 2000, 2002, 2004:
    • Yielded 1 systematic review
      • Millar, D., Light, J., & Schlosser, R. (2000). The impact of AAC on natural speech development: A meta-analysis. In Proceedings of the 9th biennial conference of the International Society for Augmentative and Alternative Communication (pp. 740-741). Washington, DC: ISAAC.
  • ASHA Convention Abstracts 2001, 2002, 2003:
    • Yielded 1 systematic review
      • Correa, N., & Nye, C. (2001). Sign language and autism: A quantitative synthesis of single-subject research. Poster presented at the Annual Convention of the American Speech-Language Hearing Association. ASHA Leader, 6(15), 189.
let s take stock of reviews
Let’s take stock of reviews
  • 2 systematic reviews
    • 1 on AAC, natural speech production & DD
    • 1 on manual signing and autism
      • ---> examine for individual studies
  • 13 narrative reviews
    • Mirenda (2003), Blischak et al. (2003), Goldstein (2002), Mirenda (2001), Schlosser & Blischak (2001), Koul et al. (2001), Sigafoos & Drasgow (2001), Bondy (2001), Bondy (1998), Mirenda & Schuler (1988), Hedbring (1985), Kiernan (1983), Bonvilllian (1981)
      • ---> examine for sections on autism & natural speech production & individual studies
slide70
5. Implement search for studies - PsycINFO

Add limiters (quality filters)

Drop the peer-reviewed part

slide73
5. Implement search for studies again - PsycINFO

Add relevant free-text terms

6. Examine the results (studies) again - PsycINFO

slide75
5. Implement search for studies - ERIC

6. Examine the results (studies) - ERIC

taking stock of studies
Taking stock of studies
  • From the two systematic reviews:
    • Barrera, Lobato-Barrera, & Sulzer-Azaroff, 1980, Benaroya, Wesley, Ogilvie, Klein, & Meaney, 1977; Bondy & Frost, 1994; Bonta & Watters, 1983; Casey, 1978; Fulwiler & Fouts, 1976; Kouri, 1988; Yoder & Layton, 1988
  • From database searches:
    • Ganz (2004), Tincani (2004), Sigafoos et al. (2003), Charlop-Christy et al. (2002), Anderson (2002), Forsey (1996), Buday (1995), Kouri (1988), Yoder & Layton (1988), Shimizu (1988), Carr (1984), Ferrarese (1982), Creekmore (1982), Konstanteras (1979)
ebp search example 3 aac and aphasia
EBP Search Example 3: AAC and Aphasia
  • Begin with Scenario: A clinician has a patient with aphasia on the caseload and needs to know what AAC intervention strategies have been used in similar cases and what were the results.
  • Consider your question: What AAC intervention strategies have been used successfully with patients with aphasia?
    • type of aphasia not further specified at the beginning of the search to screen a broad range of studies that can be narrowed down later
ebp search example 3 aac and aphasia cont
EBP Search Example 3: AAC and Aphasia (cont.)

3. Extract general keywords/quality filters from question

  • Direct extractions
    • Aphasia
    • AAC
    • Augmentative and alternative communication
    • Communication
    • Aided communication
    • Unaided communication
    • Sign language
    • Intervention
ebp search example 3 aac and aphasia cont82
EBP Search Example 3: AAC and Aphasia (cont.)

4. Determine and prioritize appropriate evidence sources:

  • Start with specialized databases for pre-filtered evidence:
    • Cochrane/DARE: 6 hits on “augmentative and alternative communication”, none related to aphasia; 243 hits on “aphasia” but AAC not included in any of them
  • General databases better choice, most appropriate for aphasia related topics:
    • (a) PsycINFO
    • (b) MEDLINE
    • (c) Cumulative Index of Nursing and Allied Health Literatures (CINAHL)
ebp search example 3 aac and aphasia cont83
EBP Search Example 3: AAC and Aphasia (cont.)

5.(a) Implement Search - PsycINFO:

  • Select appropriate keywords, chose major PsycINFO headings:

To locate aphasia relevant entries:

    • 1. Enter “aphasia” (already major heading); perform search

To locate AAC relevant entries:

    • 2. Enter “augmentative communication”, map it to subject headings, then also chose “sign language”; ignore “nonverbal communication” and “communication systems” because no additional results; perform search
    • 3. Enter “symbolism” (major heading) to retrieve symbol-related entries; perform search
ebp search example 3 aac and aphasia cont84
EBP Search Example 3: AAC and Aphasia (cont.)

5. (a) Implement Search - PsycINFO (cont.):

  • Combine results from (2.) and (3.) to summarize all AAC entries using OR operator
  • Combine this summary with (1.) using AND operator to obtain results relevant to AAC and aphasia  89 entries
ebp search example 3 aac and aphasia cont85
EBP Search Example 3: AAC and Aphasia (cont.)

5. (a) Implement Search - PsycINFO (cont.):

  • Narrow down results using appropriate quality filters:
    • Click on “Limit”, on next screen check general filters “English Language” and “Peer Reviewed Journals”  64 entries, peer-review quality
    • Several filters available under “Form/Content Types”, select:“empirical study”  47 entries,“quantitative study”  2 entries,“literature review”  3 entries,“clinical case report”  15 entries“qualitative study”  1 entry
ebp search example 3 aac and aphasia cont86
EBP Search Example 3: AAC and Aphasia (cont.)

6. (a) Examine Results

  • Final results for PsycINFO search:
    • 64 entries from peer-reviewed journals
    • “empirical study”  47 entries,“quantitative study”  2 entries,“literature review”  3 entries,“clinical case report”  15 entries“qualitative study”  1 entry
    • Need to review these results in terms of content (relevance to individual case) and research design (quality of evidence)
    • Save search for later use, print out or e-mail search results
ebp search example 3 aac and aphasia cont89
EBP Search Example 3: AAC and Aphasia (cont.)

5. (b) Implement Search - MEDLINE

  • Select appropriate keywords, consider Medical Subject Headings (MeSH):

To locate aphasia relevant entries:

  • 1. Enter “aphasia” (already a MeSH term); perform search

To locate AAC relevant entries:

  • 2. Enter “graphic symbols”, map it to subject headings, then chose MeSH terms “Communication Aids for Disabled”, “Symbolism” and also check “graphic symbols” as keyword; ignore “communication” because it reveals too many unrelated entries; perform search
  • 3. Enter “manual communication” (MeSH term), perform search
  • 4. Enter “communication methods, total” (MeSH term), perform search
ebp search example 3 aac and aphasia cont90
EBP Search Example 3: AAC and Aphasia (cont.)

5. (b) Implement Search -MEDLINE (cont.)

  • Combine results from (2.), (3.), and (4.) to summarize all AAC entries using OR operator
  • Combine this summary with (1.) using AND operator to obtain results relevant to AAC and aphasia  69 entries
  • Narrow down results using appropriate quality filters:
    • First, try to locate pre-filtered evidence  checking “Limit to: ‘Review articles’ and ‘Systematic Reviews’” reveals no results, field not advanced to that level yet, need to descend in evidence hierarchy
    • Click on “Limit”, on next screen chose filters “English Language” and under Publication Types chose “Case Reports”
ebp search example aac and aphasia cont91
EBP Search Example: AAC and Aphasia (cont.)

6. (b) Examine results:

  • 18 “case reports” on AAC and aphasia, 13 are new entries not listed in the original 62 from PsycINFO
  • “case reports” not clearly defined, there is still the need to review these studies in terms of design quality (e.g., whether experimental single subject study or narrative report)
  • review titles and abstracts (if needed) to identify those most relevant to your case
  • Save search for later use, print out or e-mail search results
ebp search example 3 aac and aphasia cont94
EBP Search Example 3: AAC and Aphasia (cont.)

5. (c) Implement Search - CINAHL:

  • Select appropriate keywords, chose major CINAHL headings:

To locate aphasia relevant entries:

  • 1. Enter “aphasia” (already major heading); perform search

To locate AAC relevant entries:

  • 2. Enter “AAC”, map it to subject headings, then chose “Alternative and Augmentative Communication” and “Communication Aids for Disabled”; ignore “non-verbal communication” because it does not lead to additional results; perform search
  • 3. Enter “sign language” (major heading) to retrieve unaided communication modes; perform search
ebp search example 3 aac and aphasia cont95
EBP Search Example 3: AAC and Aphasia (cont.)

5. (c) Implement Search - CINAHL (cont.):

  • Combine results from (2.) and (3.) to summarize all AAC entries using OR operator
  • Combine this summary with (1.) using AND operator to obtain results relevant to AAC and aphasia  33 entries
ebp search example 3 aac and aphasia cont96
EBP Search Example 3: AAC and Aphasia (cont.)

5. (c) Implement Search - CINAHL (cont.):

  • Narrow down results using appropriate quality filters:
    • Click on “Limit”, on next screen check general filters “English” and “Research”  16 entries, research-based
    • Under “Journal Subsets” select “Peer Reviewed Journals”  13 entries, peer-review quality
    • Look at quality filter “Publication types”, several options: “clinical trial”, “systematic review” and “review” reveal no hits, “case study” results in 4 entries, if these are applicable distinguish between single-subject research designs and narrative case reports
    • Interesting, but not yet applicable (no results at this point): Under “Special Interest Category” filter on “Evidence Based Practice”
ebp search example 3 aac and aphasia cont97
EBP Search Example 3: AAC and Aphasia (cont.)

6. (c) Examine Results - CINAHL:

  • 16 research based entries, 13 of which did not appear in MEDLINE, and 8 not in either MEDLINE or PsycINFO
  • 13 peer-reviewed
  • 4 “case studies”
  • Again, need to review for quality of research design
  • Review titles and abstracts (if needed) to identify those most relevant to your case
  • Save search for later use, print out or e-mail search results
slide100
Locating in press-articles through
    • Publisher websites (e.g., MetaPress, Science Direct, etc.)
ebp search example 3 aac and aphasia cont102
EBP Search Example 3: AAC and Aphasia (cont.)

6. (a, b, c) Examine overall results from PsycINFO, MEDLINE, and CINAHL:

  • 83 unique entries covering range of aphasia subtypes, interventions, research designs, and range in quality (!)
    • Need to review these results in terms of content (relevance to individual case) and research design (quality of evidence)
      • Start with information embedded in title, then read abstract, and if the content is still unclear retrieve complete article to review in further detail
example 3 lessons
Example 3 Lessons
  • No single database covers all relevant literature on a given topic
  • Each database requires slightly different search strategy re: combination of key words and phrases
  • Even if correct keywords are used, irrelevant results may still show up (accuracy of indexing),
  • Databases vary in terms of available filters
    • Not all filters are helpful
  • Databases use different terms and sometimes ambiguous labels to classify filtered search results
    • Example: “clinical case reports” can cover qualitative case study or single-subject research design
    • Filtered results still need to be reviewed by hand in further detail re: quality of the research design
ebp search example 4 efficacy of aac in autism
EBP Search Example 4: Efficacy of AAC in Autism
  • Begin with scenario: A researcher aims to identify the research base for AAC in autism, wants to investigate effectiveness of AAC interventions for individuals with autism, and decides to conduct quantitative synthesis of intervention literature (meta-analysis)
ebp search example 4 efficacy of aac in autism105
EBP Search Example 4: Efficacy of AAC in Autism
  • Consider your question(s):
    • What AAC interventions (e.g., aided, unaided, partner training, etc.) are effective in terms of behavior change, generalization, and maintenance in individuals with autism?
    • What AAC interventions are effective in yielding specific outcomes (e.g., language acquisition, functional communication training, participation, etc.)?
    • Which AAC interventions are more effective than others in general and in yielding specific outcomes?
    • What are research gaps and
    • methodological gaps in the intervention literature?

Note: more comprehensive approach of systematic review

ebp search example 4 efficacy of aac in autism106
EBP Search Example 4: Efficacy of AAC in Autism

3. Extract general keywords/quality filters from question

  • Direct extractions
    • AAC
    • Augmentative and alternative communication
    • Communication
    • Aided communication
    • Unaided communication
    • Manual signing, signing
    • Aided Language Stimulation
    • Augmented Input
    • Autism
  • Extrapolations
    • Group studies
    • Single-subject experimental designs
ebp search example efficacy of aac in autism
EBP Search Example: Efficacy of AAC in Autism
  • Note different approach of searches for systematic reviews (as outlined above), particularly:
      • Multi-faceted, i.e., different searches and search strategies complement one another
      • Targeted, but broad and very comprehensive because of need to locate and finally evaluate all existing research studies out there
  • What can be learned from systematic reviews to enhance searches for EBP?
    • Evidence for AAC scattered widely, often scarce and difficult to locate through traditional channels (e.g., databases)
    • Search strategies common for systematic reviews can be of benefit when evidence is hard to find  improve EBP search through multiple strategy approach
ebp search example 4 efficacy of aac in autism108
EBP Search Example 4: Efficacy of AAC in Autism

4. Determine and prioritize appropriate evidence sources:

Focus on computerized database searches covering

  • Cumulative Index to Nursing and Allied Health Literature (CINAHL)
  • Dissertation Abstracts International
  • Educational Resources Information Center (ERIC)
  • Language and Linguistics Behavior Abstracts (LLBA)
  • PsychINFO
ebp search example 4 efficacy of aac in autism109
EBP Search Example 4: Efficacy of AAC in Autism

5. Implement search

(a) Computerized databases with selected keywords as outlined above

Plus additional search strategies (multi-faceted search):

(b) Hand Search - "AAC Theses and Dissertations”

  • published report "AAC Theses and Dissertations" (Lloyd, Koul, & Arvidson, 1993, 1994) in Journal of AAC
  • includes abstracts and bibliographic information of 73 theses and dissertations
  • facilitates the further retrieval of unpublished theses
ebp search example 4 efficacy of aac in autism110
EBP Search Example 4: Efficacy of AAC in Autism

5. Implement search (cont.)

  • Hand Search - Journals
    • 39 professional journals, identified as possible publication outlets for AAC interventions
    • Covers journals that may not be indexed in databases
    • Hand search does not rely on key word indices provided by the journals; the accuracy of these indices always depends (e.g., judgment of authors, indexers/editor)
    • How to hand search: systematic search of table of contents for relevant titles; if titles appear relevant, examine the abstract for further relevance
ebp search example 4 efficacy of aac in autism111
EBP Search Example 4: Efficacy of AAC in Autism

5. Implement search (cont.)

  • Selection criteria rather than quality filters; applied by researcher when reviewing obtained literature:
    • Intervention must pertain to AAC (according to ASHA 1989 definition; Facilitated Communication literature excluded)
    • Intervention target must include individuals with autism spectrum disorders (ASD)
    • Experiment employs single-subject or group design
    • Experiment needs to be written as an article in a refereed journal, documents available through ERIC, or unpublished MS/doctoral theses
    • Dated between 1976 and 2004
ebp search example 4 efficacy of aac in autism112
EBP Search Example 4: Efficacy of AAC in Autism

5. Implement search (cont.)

  • Selection criteria rather than quality filters; applied by researcher when reviewing obtained literature:
    • Intervention must pertain to AAC (according to ASHA 1989 definition; Facilitated Communication literature excluded)
    • Intervention target must include individuals with autism spectrum disorders (ASD)
    • Experiment employs single-subject or group design
    • Experiment needs to be written as an article in a refereed journal, documents available through ERIC, or unpublished MS/doctoral theses
    • Dated between 1976 and 2004
ebp search example 4 efficacy of aac in autism113
EBP Search Example 4: Efficacy of AAC in Autism

6. Examine Results

  • Literature search revealed a total of 270 publications related to AAC & autism (excluding FC)
  • Empirical studies: 134
    • Descriptive clinical case studies: 7
    • group designs: 13
    • longitudinal designs: 3 (2 descr./1 experim.)
    • single-subject designs: 81
    • design flawed, etc. : 30
  • 95 studies met inclusion criteria re: research design quality
example 4 lessons
Example 4 Lessons
  • Searches for systematic reviews are different from EBP searches, more comprehensive and multiple search strategies that complement one another
  • Electronic databases, even if combined, do not reveal all available evidence
    • AAC relevant journals may not be indexed
    • Database indeces may not be accurate
  • “Nontraditional ways” to search can reveal further useful evidence, i.e., hand searches and ancestry searches, but practitioners have to decide how feasible
    • Hand search in example lead to 28 additional studies that did not show up in databases
  • Research evidence can also be found in unpublished literature such as PhD and MS theses (although not peer reviewed); 6 PhD and 1 MS theses located in example
example 4 lessons cont
Example 4 Lessons (cont.)
  • In this particular case of AAC & autism:
    • Search reveals lots of anecdotal evidence, less data-based
    • Considerable amount of studies with flaws in research design or insufficient (pre-experimental) design quality

 Researchers and clinicians need to be cautious in interpreting and evaluating these findings, need to keep EBP guidelines and evidence hierarchy in mind

further sources for ebp searches
Further Sources for EBP Searches
  • ProQuest Digital Dissertations formerly known as Dissertation Abstracts International (DAI)
  • Linguistics and Language Behavior Abstracts (LLBA)
  • Web of Science
  • Internet
    • General search engines
    • Specialized search engines
    • Meta-searches and meta-search engines
    • Evaluation of Internet information
proquest digital dissertations pqdd
ProQuest Digital Dissertations (PQDD)
  • PQDD is an online version of the print counter-part Dissertation Abstracts International (DAI)
  • Dissertations and theses may contain valuable research findings
  • Exclusion can introduce bias in the EBP process
  • Most theses undergo internal peer-review process, i.e., acceptance by committee
  • PQDD holds more than 2 million entries from 1861 to the present (updated each semester)
proquest digital dissertations pqdd118
ProQuest Digital Dissertations (PQDD)
  • More than 1.7 million full-text versions available in paper or microform, can be ordered online
  • More than 450,000 full-text versions available in digital format for online download from Dissertation Express website
    • Entries from 1997 forward
  • Only last 2 years can be accessed free of charge
  • Broader searches require subscription
  • Downloading full-text versions often requires additional fee payment
example 5 aac early intervention
Example 5: AAC & Early Intervention

5. Implement search - CINAHL

6. Examine the results - CINAHL

example 5 continued
Example 5 continued

5. Implement search - PsycINFO

6. Examine the results - PsycINFO

proquest digital dissertations pqdd122
ProQuest Digital Dissertations (PQDD)
  • Brief search example: AAC & Early intervention
  • Keywords:
    • “augmentative communication”  65 hits
    • “alternative communication”  86 hits
    • “augmentative and alternative communication”  51 hits
    • “AAC”  156 hits, but many non-relevant
    • “sign language”  621 hits
    • “sign language” AND NOT “deaf”  204 hits
  • No filters available for research design quality
isi web of science
ISI Web of Science
  • Five high-quality databases containing information from journals in all research areas
    • Three relevant for AAC:
      • Science Citation Index Expanded
      • Social Sciences Citation Index
      • Arts & Humanities Citation Index
    • Contain references cited by authors of indexed journals
    • Option to use forward citation search where cited references are used as search terms
    • Can’t delimit citations to meet design criteria
isi web of science cont
ISI Web of Science (cont.)
  • May also search by topic, author, source title, and address
  • Searching by author may be more cost-efficient because of possible fees for forward citation search
  • Requires either an individual or university library subscription
searching for evidence on the internet
Searching for evidence on the Internet
  • Internet offers a vast array of information pertaining to AAC
  • Challenge when obtaining too many sites of interest but different quality
  • Lack of quality control is a major concern
  • Points to consider when conducting evidence searches
    • Knowing which search engines will yield best results
    • Knowing how to assess the quality of the retrieved information
general search engines
General search engines
  • Search engine:
    • Software program built on top of large databases containing web page files
    • Matches the database content to specified search terms
    • Databases compiled through “robots”, ”spiders”, or “crawlers (programs searching and indexing webpages)
    • Each search engine uses own set of criteria to decide what to include in its database
    • Different ways to organize search results for users, e.g., link popularity vs. common themes
general search engines cont
General search engines (cont.)
  • Web directories:
    • Instead of “spiders” human editors review and index links
    • Guidelines for web sites to be included in index
    • Directory editor looks at quality of a site: functionality, content and design
    • Directory indexes
      •  small number of, but higher quality links
    • Example: Yahoo! (in the past), Open Directory Project (http://dmoz.org)
general search engines cont140
General search engines (cont.)
  • Hybrid search engines:
    • Latest generation
    • Combination of traditional search engine with a directory
    • Top ten search sites are hybrids
    • Example: Google uses Open Directory Project to supplement its automatically generated listings (Shapiro & Lehoczky, 2004)
general search engines cont141
General search engines (cont.)
  • Most popular search engines by percentage of home and work users (as of June 2004)
    • Google, http://www.google.com (41,6%)
    • Yahoo, http://www.yahoo.com (31,5%)
    • MSN, http://www.msn.com (27.4%)
    • AOL Search, http://www.aolsearch.com (13.6%)
    • Ask Jeeves, http://www.ask.com (7.0%)
    • Overture, http://www.overture.com (5.1%)

(Source: Nielsen//Netratings, 2004)

    • Others: Altavista (http://www.altavista.com); Hotbot (http://www.hotbot.com); Lycos (http://www.lycos.com)
  • Currently, Google and Yahoo leading the market
general search engines cont142
General search engines (cont.)
  • Search engines differ significantly in terms of power and user-friendliness of their interfaces
  • Advanced search options offered:
    • Boolean operators (AND, NEAR, OR)
    • Truncation (e.g., communicat*)
    • Search within results (only Google, Hotbot, and Lycos)
general search engines cont143
General search engines (cont.)
  • Internet directories (e.g., dmoz): good for beginning searches and to distinguish between different categories, but may not be up to date and limited in scope
  • Not every item appears in every search engine
  • Even the most current search engines cover less than half of all the content on the internet (e.g., Google accesses only 15-16%)

- in fall of 2005 Yahoo reported to possess an index of 19 billion web documents; Google’s index at the time was estimated at 8 billion documents (Sherman, 2005)

general search engines cont144
General search engines (cont.)
  • No recent updates on index sizes by either Yahoo or Google
  • Google, Yahoo and other search engines only access “surface web”  static web documents that are accessible to search engines
  • “Deep web” 50x bigger than “surface web”, consists of web documents dynamically generated by database servers: this information tends to be more recent, more topic-focused, and more relevant, but these sites are difficult to retrieve for search engine crawlers(Sherman, 2005)

 Repeat search using different search engines!

specialized search engines
Specialized search engines
  • Consider for locating higher quality research evidence on the internet
  • Scirus (http://www.scirus.com)
    • Focuses on scientific content only
    • Searches the web and electronic journal sources
    • Locates more peer reviewed articles
    • Recognizes formats such as PDF and Postscript
    • Most beneficial to locate research data
specialized search engines cont
Specialized search engines (cont.)
  • Google Scholar (http://www.scholar.google.com)
    • Peer-reviewed papers, theses, books, preprints, abstracts and technical reports from all broad areas of research are available
    • Results are ordered by how relevant they are to the query
    • Automatically analyzes and extracts references and presents them as separate results, even if the documents they refer to are not online
meta searches and meta search engines
Meta-searches and meta-search engines
  • Simultaneously explore the databases of multiple sets of individual search engines
  • Summarize results from a broad range of different search engines
  • Search is more comprehensive without loosing the general overview perspective
  • Meta-search engines
    • Ixquick (http://www.ixquick.com); features include coverage of 12 most familiar search engines and directories, result rankings, and ratings for most appropriate individual search engine
    • Copernic (http://www.copernic.com)
    • DogPile (http://www.dogpile.com)
    • Metacrawler (http://www.meta-crawler.com)
evaluation of information located on the internet
Evaluation of information located on the Internet
  • A systematic evaluation of the obtained web documents should be performed to determine the quality and usefulness of the information or data presented
  • Evaluation of validity is necessary because there is a lack of quality control on the internet
  • Five criteria for evaluation
    • Accuracy
    • Authority
    • Objectivity
    • Currency
    • Coverage
accuracy
Accuracy
  • Need for content to be valid and “without errors of fact, interpretation, or judgment” (Eysenbach et al., 2002)
  • Information needs to be disclosed re:
    • Who authored the web document
    • Whether or not that person is qualified to write the information provided
    • If the provided content is reliable and error-free
    • What kind of sources are cited
authority
Authority
  • Overall credibility of the author and publisher of a web document
  • To determine authority look at:
    • Header or footer for an affiliation
    • The Internet domain (e.g., .edu, .com, .ac.uk, .org, and .net)
  • Credentials of the author should be reviewed
objectivity
Objectivity
  • Depending on website’s purpose (advertising, advocacy, opinion, scholarship, etc.) the provided information may be biased
  • To determine objectivity consider:
    • Why the document was created
    • For whom it was written
    • What opinions, if any, are expressed by the author
  • Disclosure of ownership and sponsorship are essential
currency
Currency
  • Look at when the web document or its web site was first produced and updated
  • Check the number of dead links located on the web page
    • If links cannot be accessed, there is a high likelihood that information on the web page from which the link was accessed is no longer current
coverage comprehensiveness and accessibility of information
Coverage, comprehensiveness, and accessibility of information
  • Web documents containing more detail most likely provide more information and increased coverage of a topic
  • Credibility increases with links to reputable web sites
  • Many web pages contain links to biased sites and advertisements
  • Accessibility of web pages is important. Accessible sites provide a text equivalent for all non-text elements to be read in screen-readers to users with visual impairments
look out for
Look out for
  • Schlosser, R. W., Wendt, O., Angermeier, K. L., & Shetty, M. (2005). Searching for evidence in augmentative and alternative communication: Navigating a scattered literature. Augmentative and alternative communication, 21 (4), 233-255.
  • Schlosser, R. W., Wendt, O., Bhavnani, S., & Nail-Chiwetalu, B. (under review). Benefits of “adapted pearl growing” for evidence-based practice and implementing systematic reviews: A short report. Manuscript submitted for publication.
references
References
  • American Speech-Language-Hearing Association (ASHA) (2003). Evaluating Web sites. Retrieved November 23, 2003 from the ASHA web site: http://www.asha.org/sitehelp/websites.htm
  • Beaven, O. (2002). Searching the literature. In J. V. Graig, & R. L. Smyth (Eds.), The evidence-based practice manual for nurses (pp. 45-85). Edinburgh: Churchill Livingstone.
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  • Blair-Lockney, E. (2003). AJSLP reaches major milestone – MEDLINE indexing. The ASHA Leader, April 1, 2003, 3.
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  • Cook, D. J., Mulrow, C. D., & Haynes, R. B. (1997). Synthesis of best evidence for clinical decisions. Annals of Internal Medicine, 126, 376-380.
  • Cook, D. J., Sackett, D.L., Spitzer, W. O. (1995). Methodologic guidelines for systematic reviews of randomized control trials in health care from the Potsdam Consultation on Meta-Analysis. Journal of Clinical Epidemiology, 48, 167-171
  • Cooper, H. & Hedges, L. V. (1994). The handbook of research synthesis. New York: Russell Sage Foundation.
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for further information contact
For further information contact
  • Oliver Wendt:
    • E-mail: olli@purdue.edu
  • Ralf W. Schlosser:
    • E-mail: r.schlosser@neu.edu
  • Handout available on

Purdue AAC website:

http://www.edst.purdue.edu/aac(click on “Recent Presentations”)