RUNNING HEAD: Computer-assisted intervention Cluster Randomized Controlled Trial Evaluating the Effectiveness of Computer-Assisted Intervention Delivered by Educators for Children with Speech Sound Disorders Sharynne McLeod Charles University, Australia Elise Baker The University of Sydney, Australia Jane McCormack Charles University, Australia Yvonne Wren Bristol Speech and Language Therapy Research Unit, UK University of Bristol, Bristol, UK Sue Roulstone Bristol Speech and Language Therapy Research Unit, UK University of the West of England, UK Kathryn Crowe Sarah Masso Charles University, Australia Paul White University of the West of England, UK Charlotte Howland Charles Sturt University, Australia The University of Sydney, Australia Trial Trial
Table 4 summarizes means, standard deviations and statistical significance for the per protocol analyses. Speech production accuracy Percentage of consonants correct on the Diagnostic Evaluation of Articulation and Phonology (DEAP, Dodd et al., 2002). DEAP data for true controls and true PFSS is summarized in Table 4. Analysis using an ANOVA for a 2 by 3 mixed design for these data gives the same statistical conclusions as the randomized groups analysis. That is, a statistically significant change in mean PCC on the Phonology subtest of the DEAP between the Stages (p < .001, = .324), and a statistically significant average difference between the two Groups (p = .003, = .135), but with a non-significant interaction between Stage and Group (p = .916, = .001). Primary intervention target phonological probes. Analysis of the per protocol subset indicates statistically significant change in between the Stages (p < .001, = .283), but with no average significant difference between the two Groups (p = .286, = .019), and any changes in means were not group dependent (p = .614, = .008) (see Table 4). Intelligibility in Context Scale (ICS, McLeod et al., 2012a). In the per protocol analysis, average mean ICS did not significantly differ between the two Groups (p = .372, = .047), did not significantly differ between the three Stages (p = .243, = .008), and differences between groups did not significantly change between the Stages (p = .996, < .001). Emergent literacy skills Three emergent literacy measures were collected once before intervention (stage 3), and at least once post intervention (stages 5 and/or 6) to consider outcomes over time (Table 4), as noted in the intention-to-treat section.
Lancaster, G., Keusch, S., Levin, A., Pring, T., & Martin, S. (2010). Treating children with phonological problems: does an eclectic approach to therapy work? International Journal of Language and Communication Disorders, 45(2), 174–181. Law, J., Boyle, J., Harris, F., Harkness, A., & Nye, C. (2000). Prevalence and natural history of primary speech and language delay: Findings from a systematic review of the literature. International Journal of Language and Communication Disorders, 35, 165-188. Law, J., Garrett, Z., Nye, C. (2003/2010). Speech and language therapy interventions for children with primary speech and language or disorder. Cochrane Database of Systematic Reviews, Issue 3. Art. No.: CD004110. DOI: 10.1002/14651858.CD004110. Long, S. H., Fey, M. E., & Channell, R. W. (2008). Computerized profiling (Version MS-DOS version 9.7). Milwaukee, WI: Marquette University. McAllister, L., McCormack, J., McLeod, S., & Harrison, L. J. (2011). Expectations and experiences of accessing and participating in services for childhood speech impairment. International Journal of Speech-Language Pathology, 13, 251-267. McCormack, J., Baker, E., Crowe, K., Masso, S., McLeod, S., Wren, Y., & Roulstone, S. (2016). Implementation fidelity of a computer-assisted intervention for children with speech sound disorders. Manuscript in submission. McCormack, J. M., & Verdon, S. E. (2015). Mapping speech pathology services to developmentally vulnerable and at-risk communities using the Australian Early Development Census. International Journal of Speech-Language Pathology, 17(3), McLeod, S. (2004). Speech pathologists' application of the ICF to children with speech impairment. International Journal of Speech-Language Pathology, 6(1), 75-81.
Table 1. Eligibility criteria from Stages 1, 2 and 3 for inclusion in stage 4 (intervention/control) of the Sound Start Study Stage Skill Criteria Assessment tool Informant Stage 1: Screening for eligibility by parents/teacher Speech “Difficulty talking and making speech sounds” (yes or a little concerned) Parent Evaluation of Developmental Status (PEDS, Glascoe, 2000) Parent and/or teacher Speech Speech not to family and/or others Parent questionnairea Parent and/or teacher Medical and developmental history Reported no persistent hearing loss, lip/palate or developmental delay Parent questionnairea Parent and/or teacher English language use English language skills had to be equivalent to or better than skills in the other language Parent questionnaire Parent Stage 2: Assessed for eligibility following direct screening assessment by SLP Speech Percentage of consonants correct (PCC) standard score ≤6 (i.e., greater than one standard deviation below the mean) Had a phonological pattern that could be treated by PFSS Diagnostic Evaluation of Articulation and Phonology – Phonology subtest (DEAP, Dodd et al., 2002) Direct assessment Nonverbal intelligence Year 1: Nonverbal Score >79 (%ile rank of >8). Year NVI >70 (%ile rank of >2). Primary Test of Nonverbal Intelligence Ehrler & McGhee, 2008); Direct assessment 3: Assessed for eligibility following direct comprehensive assessment by SLP Receptive vocabulary Receptive vocabulary score less than 2 SD below the mean Peabody Picture Vocabulary Test - Fourth Edition Dunn & Dunn, 2007) Direct assessment Hearing Passed hearing screening of all frequencies at 40dB during Stage 2 or Stage 3 Pure-tone audiometry (500, 1000, 2000, 4000 Hz) at 40dB Direct assessment
Consonant stimulabilitya Number of English consonants /24 123 22.3 (1.8) 22.0 (1.9) .338 Phonological awareness composite scorea CTOPP-2 phonological awareness composite score 122 89.0 (11.5) 87.4 (10.4) .432 Nonverbal IQa raw score 123 22.4 (8.8) 22.0 (8.9) .788 Receptive vocabularya PPVT raw score 123 68.1 (18.3) 71.5 (19.2) .309 Note. aM (SD), bn (%); IRSAD, Index of Relative Socio-Economic Disadvantage; DEAP, Diagnostic Evaluation of Articulation and Phonology (Dodd et al., 2002); CTOPP-2, Comprehensive Test of Phonological Processing – 2 (Wagner et al., 2013); PTONI, Primary Test of Nonverbal Intelligence (Ehrler & McGhee, 2008); PPVT, Peabody Picture Vocabulary Test (Dunn & Dunn, 1997). 3. Outcomes of the Intervention and Control Groups in the Sound Start Study: Intention to Treat (Complete Cases) Measure Group Valid n Stage 2/3 Stage 5 Stage 6 Effect F p M (SD) M (SD) M (SD) Speech Production Percentage of consonants correct DEAP Intervention 59 69.25 (9.13) 75.40 (10.27) 76.06 (9.99) Stage 42.36 <.001 .287 Control 48 64.34 (11.74) 69.77 (12.97) 71.14 (12.78) Group Interaction 6.98 0.14 .009 .874 .062 .001 Primary intervention target probes Sound Start Study probes Intervention 59 71.27 (25.7) 47.14 (38.1) 43.28 (36.0) 48.79 <.001 .319 Control 47 73.30 (28.4) 57.41 (36.5) 48.19 (36.2) Group Interaction 0.99 1.12 .322 .329 .009 .011 Intelligibility ICS Intervention 30 3.75 (0.36) 3.95 (0.39) 3.97 (0.45) Stage 4.14 .019 .094