The Nuffield Dyspraxia Programme (NDP3) and the Evidence Base
The treatment approach of the Nuffield Dyspraxia Programme (NDP3) has been evaluated in two randomised controlled trials (RCTs) and in a number of single case studies. Successful outcomes have been reported for NDP3 both in the RCTs and in case studies.
NDP3 is included as an intervention on The Communication Trust’s What Works database and currently has a rating of moderate evidence, in line with other published speech interventions.
Randomised Controlled Trial (Murray, McCabe & Ballard, 2015)
Twenty-six children, aged 4 to 12 years, diagnosed with mild to severe idiopathic Childhood Apraxia of Speech (CAS) were randomly assigned to receive either NDP3 or Rapid Syllable Transition (ReST) treatment. Twelve treatment sessions were delivered intensively (one hour a day, four days a week for three weeks) by trained student speech pathologists in a university clinic. NDP3 treatment followed the Therapy manual advice (Williams & Stephens 2004) and each child worked on three individually selected goals (segmental, structural and prosodic) and received a combination of Knowledge of Performance (KP) and Knowledge of Results (KR) feedback after each production. Post-treatment outcomes showed significant and large treatment effects for the 13 children who received NDP3 intervention, as well as moderate generalisation to untreated real words. Both NDP3 and ReST treatment were deemed to have support for clinical use.
Randomised Controlled Trial (McKechnie, Ahmed, Gutierrez-Osuna et al. 2020)
Positive treatment effects were replicated in a second RCT (McKechnie, Ahmed, Gutierrez-Osuna et al., 2020), for 14 children (4-10 years, with mild to severe idiopathic CAS), who all received NDP3 treatment, delivered by similar personnel over the same duration and intensity, as in the Murray et al. 2015 study. Therapy activities were presented using NDP3 images on an android tablet, and the types and schedules of feedback given varied. Children were randomly assigned to receive either: (a) high frequency KP and KR feedback and cues in each treatment session (as in the Murray et al. 2015 study) or (b) high frequency KP and KR feedback and cues in one session a week, followed by three sessions with only KR feedback given. Only the children in group (a) showed immediate gains in accuracy, but over time both groups produced significant gains. Further research was recommended to understand more about the use of different feedback schedules, but this RCT provides additional evidence of the effectiveness of NDP3 as a treatment approach for children with CAS.
The most recent Cochrane Database Systematic Review of Interventions for Childhood Apraxia of Speech (CAS) (Morgan, Murray & Liegeois, 2018) reported that only NDP3 and Rapid Syllable Transition Treatment (ReST) had RCT level evidence to support their use. McCabe, Murray & Thomas (2020) described NDP3 and ReST as current gold standard treatments for CAS, in their summary of evidence regarding Childhood Apraxia of Speech (CAS) on the University of Sydney website.
For further details, see:
McCabe, P., Murray, E., & Thomas, D. (2020). Evidence Summary – Childhood Apraxia of Speech – January 2020. http://sydney.edu.au/health-sciences/rest/resources.shtml.
McKechnie, J., Ahmed, B., Gutierrez-Osuna, R., Murray, E., McCabe, P., & Ballard, K.J. (2020). The influence of type of feedback during tablet-based delivery of intensive treatment for childhood apraxia of speech. Journal of Communication Disorders, 87, 106026. https://10.1016/j.jcomdis.2020.106026
Morgan, A., Murray, E. & Liegeois, F. (2018). Interventions for childhood apraxia of speech. Cochrane Database of Systematic Reviews, 2018 (5).
Murray, E. McCabe, P., & Ballard, K.J. (2015). A randomized controlled trial for children with childhood apraxia of speech comparing Rapid syllable transition treatment and the Nuffield Dyspraxia Programme (3rd edition). Journal of Speech, Language & Hearing Research, vol 58 (3), 669-686.
Murray,E. , McCabe, P. & Ballard, K.J. (2012). A comparison of two treatments for childhood apraxia of speech: methods and treatment protocol for a parallel group randomised control trial. BMC Paediatrics, 2012, 12:112.
Six descriptive case studies are included in Chapter 7 of the Therapy manual of NDP3 (Williams and Stephens, 2004). These case studies demonstrate treatment planning and the NDP3 therapy approach in specific children, aged 4-12 years. The children all achieved intelligible speech following intervention but the duration and quantity of therapy varied and the treatment was delivered by different speech and language therapists.
Saunders (2006) reported a single case study of a 3-year-old child called Caelen, who had a dual diagnosis of autism spectrum disorder and developmental verbal dyspraxia (DVD). Saunders (2006) followed the principles of the NDP3 treatment approach and utilized the NDP3 picture resources and delivered the treatment in once weekly therapy sessions, supported by practice at home and at nursery. Caelen was reported to have made excellent progress with his speech and expressive language development, following intervention.
For further details, see:
Saunders, H. (2006). How I (2): Phonology never too soon to start. Speech and Language Therapy in Practice, Summer 2006 27-28. www.speechmag.com
Teal (2005) reported a single case study of Ruth, aged 6 ;11 years, who had persisting speech difficulties. NDP3 and Core vocabulary (Dodd, 2005) were utilized during a course of intensive therapy and both were found to be effective in bringing about change, but in different aspects of Ruth’s speech processing system. Furthermore, NDP3 also produced significant generalization to untreated words.
For further information, see:
Teal, J. (2005). An investigation into classification approaches and therapy outcomes for a child with a severe persisting speech difficulty. Unpublished MMedSci. Dissertation. Department of Human Communication Sciences, University of Sheffield.
Williams, P. & Stephens, H. (2010). The Nuffield Centre Dyspraxia Programme, (chapter 7, p.159-177), in Williams, L, McLeod, S & McCauley R (eds.) (2010) Interventions for Speech Sound Disorders in Children. Baltimore, Maryland. Brookes Publishing Co.
Belton (2006) investigated the effectiveness of NDP3 treatment for four boys with severe speech sound disorders aged 4-6 years. The children received 20 hours of individual therapy, delivered one hour per week by two experienced speech and language therapists in a real-life clinical setting. The treatment followed the principles of the NDP3 treatment approach and utilized the NDP3 pictorial resources. Assessments were carried out before and after each block of ten therapy sessions and detailed quantitative and qualitative analyses were carried out by the author. The results showed that all four children increased their phonetic inventories, reduced the number of and frequency of their phonological simplification processes and increased their intelligibility ratings following intervention. They also increased their accuracy at both single word and phrase/sentence level but there was considerable individual variation. This ranged from highly significant changes at all levels of complexity to small changes in phonetic similarity to target phonemes. The study highlighted the variability in response to intervention and the complexity of factors involved in treating children with severe speech sound disorders.
Pagnamenta & Williams (2009) compared the results of intervention for two of the children included in the above study by Belton (2006) in a paper presented at RCSLT Conference in London UK.
For further details, please see:
Belton, E. (2006). Evaluation of the Effectiveness of the Nuffield Dyspraxia Programme as a treatment approach for children with severe speech disorders. Unpublished M Sc Dissertation. Department of Human Communication Science, University College London.
Pagnamenta, E. and Williams, P. (2009). Evaluation of the effectiveness of the Nuffield Dyspraxia Programme in treating two children with severe speech disorders. Paper presented at the Royal College of Speech and Language Therapists Conference in London, UK.
Williams, P. (2021). The Nuffield Centre Dyspraxia Programme, (chapter 18, p.447 – 475), in Williams, L, McLeod, S & McCauley R (eds.) Interventions for Speech Sound Disorders in Children, 2nd edition. Baltimore, Maryland. Brookes Publishing Co.
Flinders (2009) evaluated the effectiveness of NDP3 treatment for two children with severe speech sound disorders aged 4-6 years (NB different children to those included in the Belton (2006) study). Both children received 10 once weekly therapy sessions, each of one hour’s duration and treatment followed the principles of the NDP3 treatment approach and utilized the NDP3 pictorial resources. The therapy was delivered by two experienced speech and language therapists and home practice was encouraged. The children’s progress was assessed using repeated measures. The results showed that both children made some improvements in their speech production but to differing degrees. One child made statistically significant gains in all areas targeted in intervention, whilst the other made slight but non-statistically significant progress. Given that both children received the same number of treatment sessions, delivered by two speech and language therapists experienced in using NDP3, and carried out similar amounts of practice at home, it seemed likely that child-specific factors were responsible for the differences in the results obtained.
For further details, see:
Flinders, H. (2009). An evaluation of therapy using the Nuffield Centre Dyspraxia Progamme with children with severe speech disorders: two single case studies. Unpublished M Sc Dissertation. Department of Human Communication Science, University College London.
Williams, P., Stephens, H. & Flinders, H. (2010) Preliminary case study evidence for The Nuffield Centre Dyspraxia Programme. Poster presented at ASHA Convention, Philadelphia, Pennsylvania, USA.
A further descriptive case study of a child called Ben, age 4;2, was reported by Murray (2017). The book chapter provides an explanation for choosing the NDP3 treatment approach over other evidence-based approaches for Ben’s initial therapy block of 12 sessions, delivered twice weekly over 6 weeks. Details are given of general and specific goal selection, stimuli selection, criterion set for moving on to next step of therapy and typical treatment activities. Ben is reported to have made good progress over the period of treatment, but further intervention was required.
For further details see:
Murray, E. (2017). Diagnosis and intervention in childhood apraxia of speech. In B.Dodd & A. Morgan (eds.) (2017) Intervention Case Studies of Child Speech Impairment (p.115-135). Guildford, Surrey, UK: J & R Press.
The current CAS treatment evidence supports a high intensity of treatment (Baker, 2012a; Baker, 2012b; Warren, 2007), involving frequent therapy sessions delivered directly by a speech and language therapist, with a high number (100+) of productions of target sounds and/or words in a one-to-one (not group) session of 45-60 minutes duration. This should be supported by frequent opportunities to practise therapy exercises in between treatment sessions (Williams & Broomfield, 2019).
Murray et al. (2015) reported that treatment involving NDP3 or ReST delivered 4 times a week, in blocks of 12-15 sessions followed by a 4-6 week break from therapy was optimal. A minimum of two sessions a week has been shown to work clinically.
In general, studies to date have shown that the greater the treatment intensity the more effective the therapy and the more efficient the progress (e.g. Edeal & Gildersleeve-Neumann, 2012).
Baker, E. (2012a). Optimal intervention intensity. International Journal of Speech-Language Pathology, 14, 401-409.
Baker, E. (2012b). Optimal intervention intensity in speech-language pathology: discoveries, challenges and unchartered territories. International Journal of Speech-Language Pathology, 14, 478-485.
Edeal, D.M., & Gildersleeve-Neumann C.E. (2011). The importance of production frequency in therapy for childhood apraxia of speech. American Journal of Speech Language Pathology, 20(2), 95-110.
McCabe, P., Murray, E., & Thomas, D. (2020). Evidence Summary –Childhood Apraxia of Speech-January 2020. http://sydney.edu.au/health-sciences/rest/resources.shtml
Warren, S.F., Fey, M.E., & Yoder, P.J. (2007). Differential treatment intensity research: A missing link to creating optimally effective communication interventions. Mental Retardation and Developmental Disabilities Research Reviews, 13 (1), 70-77.
Williams, P. & Broomfield, J. (2019). How to differentiate and manage children with developmental verbal dyspraxia from those with inconsistent phonological disorder. RCSLT Bulletin August 2019. Ask the Experts -Child speech sound disorder: special edition.