Chapter 21 Evaluating the Evidence of Therapy: Many Hands Make Light Work – Or at Least Lighter Work Rebecca McCauley

Introduction Children with speech sound disorders (SSD) account for a large percentage of children with speech and language disorders Even mild forms of SSD (often termed “articulation disorders” can affect a child’s academic and social life Given the relatively high prevalence of SSD, one would expect a wealth of validated treatment approaches This chapter examines this expectation and discusses how SLPs can use documentation collected by others as well as themselves to achieve the best possible result for their clients with SSD Two sources of data about treatments Research appraisal of treatment approaches Clinical documentation of treatment effects

The Shared Quest: What Works? Researchers and clinicians share this question Range of research designs relates to a continuum of experimental control The three “E”s Efficacy Effectiveness Effects Efficacy: laboratory studies that control for nuisance variables Prioritize Internal validity “Of those interventions for which research has been conducted, which can be expected to have the desired effects for a particular group of well described participants when implemented as described?” Effectiveness: naturalistic studies Prioritize External validity (generalizability) Figure 21.1 The continuum of intervention research evidence

Effects: the array of impacts we hope to have on clients (Olswang, 1997). Examples: Improved score on a standardized articulation test Higher intelligibility rating Participation in classroom activities Attitude towards speaking Quality of life

Application to Practice In clinical practice, SLPs can observe all three domains: Efficacy: Observe changes under highly supportive/simplified conditions: retest with a standardized test of articulation or phonology Effectiveness: Observe changes under natural conditions, every-day life situations: treatment probes Effects: Has work on a certain sound or sound pattern resulted in increased intelligibility during conversation?

What Current Research Has to Offer Evidence-based practice (EBP), initially developed as evidence-based medicine (Sackett et al., 1996). In the EBP process, the clinician Constructs a question that might be answered by the research literature Seeks evidence for it Weighs (appraises) the quality of the evidence Considers the evidence in light of clinical expertise and client preferences and values Applies the result of the preceding process and examines the outcomes that follow Constructs the next question … (iterative process) Following these guidelines are hypothesized to result in improved client outcomes

Figure 21.2 The iterative process of evidence-based practice

Two systematic reviews Systematic reviews of treatment approaches are “as rare as Himalayan mountain ranges in the landscape” but considered very valuable as a method of integrating findings across studies Two systematic reviews Law, Garrett & Nye (2004, 2010) One narrative review focusing on treatment of phonological disorders (not articulation, not motor speech) Baker & McLeod (2011)

Table 21.1 Levels  of evidence for studies of treatment efficacy, ranked in terms of quality and credibility from most to least credible (Adapted from Baker &McLeod, 2011a, p. 104; ASHA, 2004)

Law et al. (2004) Systematic review to identify RCTs similar enough in intent and outcomes to warrant comparison Used a meta-analysis to combine data across studies thereby supporting more powerful, reliable statements about the group of studies than could be made in a narrative summary. Only 6 studies focusing on phonological interventions were identified over a 20-year period Conclusions supported the value of these interventions as a group Especially those phonologic interventions that were administered by SLPs (rather than parents) and those that lasted over 8 weeks When measured as percent consonant correct in conversation but not when measured as number of target consonants correct in a story retell Law et al. (2010) Not much updated information; children with SSD who received intervention performed better than those who did not Criticisms about their lack of specificity: Which interventions worked well? How old were the children? How severe were the disorders?

Baker & McLeod (2011): Narrative review Included all types of reports including RTC as well as case studies 134 studies from 30 years 46 different treatment approaches 23 of these had been evaluated in more than one study 74% were associated with levels of evidence falling at Levels IIb (quasi-experimental studies) and III (non-experimental case studies) The majority of these were studies of efficacy (laboratory condition studies) rather than studies of effectiveness (field condition studies) The level of evidence was not as rigorous as in the Law et al. studies but the narrative included relevant empirical evidence and clinical expertise Here, we consider only the top seven of these approaches

Table 21.2 A sample descriptive reference, number of associated research studies and illustrative study for seven SSD interventions identified as having the greatest number of associated studies from the 23 studied interventions included in Baker & McLeod (2011a).

What Clinicians Bring to the Table Figure 21.3 Clinical and research evidence as the foundations for demonstrating that a treatment works

Joffe & Pring (2004) Survey of 98 clinicians in the UK 44% of respondents said that 40% of their caseload consisted of children with phonological disorders Choosing from a list of 14 interventions, they indicated Frequently used auditory discrimination, meaningful minimal contrast, phonological awareness, and parental involvement Almost never used Maximal contrast therapy, Cycles, core vocabulary, auditory bombardment, and a whole-language approach Often combined interventions (“eclectic approach”)

Lancaster et al, (2010) Two randomly assigned groups of 6 preschoolers with phonological disorders Initial intervention group Eclectic intervention, 8 weekly sessions of ½ hour Delayed intervention group (waitlisted) Same intervention program, started after first group had ended treatment Each group had made significant gains by the end of treatment The authors concluded that the eclectic approaches were effective The dosage (30 minutes weekly for 8 weeks) resembled the clinical practice of most SLPs

This type of research has not yet been conducted for SSD In intervention studies of reading disorders, the question of dosage and intensity has been addressed This type of research has not yet been conducted for SSD Clinicians have always tracked progress within their clinician-client dyads From one step of intervention to the next From one target to the next When exiting the client from intervention

Connections In this chapter, it was argued that the strongest evidence for treatment effectiveness comes from systematic research as well as clinical practice Different treatment approaches are described in Chapter 22 Some treatment approaches are designed for certain SSD subtypes Chapter 15 focuses on disorder subtypes Chapter 20 shows how data collected during the assessment flow into the selection of a treatment Chapter 22 shows how the selected treatment approach is translated into a treatment design and implementation

Concluding Remarks This chapter presented some starting points for examining what works in treating SSD Intervention-focused research Clinical practice research The clinician’s own tracking of client progress Some aspects can be overlooked in research-based appraisals Clinical judgment Client perspectives Emerging and future efforts to incorporate these voices will lead to more balance as the field moves forward