A single case experimental design study using an operationalised version of the Kaufman Speech to Language Protocol for children with childhood apraxia of speech

Figures & data

Table I. Summary of pre-treatment speech, language, and hearing findings.

Pre-treatment assessments
Assessment	Billy (4;6)^+			Sam (4;6)			Max (4;8)			James (4;5)
	Score	Percentile	Result	Score	Percentile	Result	Score	Percentile	Result	Score	Percentile	Result
GFTA 2^a	^64	4	**LNR	*88	21	*LNR	*89	23	*LNR	*56	1	**LNR
DEAP inconsistency assessment^b	80	−	IS	76	_	IS	76	_	IS	80	_	IS
Polysyllables word test^c
% Consonants correct	48	−	−	51	_	_	49	_	_	30	_	_
% Vowels correct	65	−	−	70	_	_	60	_	_	69	_	_
% Phonemes correct	55	−	−	59	_	_	54	_	_	46	_	_
Words with stress pattern errors^d	32/50	−	−	30/48			32/49			25/50
Syllable segregations^e	44	−	−	41			18			43
Oral and Motor Speech Protocol^f
Structure	24	−	WNL	24		WNL	24	_	WNL	24	_	WNL
Function	94	−	**LNR	90		** LNR	88	_	**LNR	88	_	**LNR
CELF-P2^g
Receptive language index	92	30	WNL	104	61	WNL	83	13	*LNR	103	58	WNL
Expressive language index	−	−	−	11	63	WNL	_	_	_	77	6	**LNR
PPVT-4^h	117	87	WNL	126	96	WNL	89	23	WNL	116	86	WNL
Hearing screen^i	Passed binaurally			^#Passed binaurally			Passed binaurally			Passed binaurally

^aGFTA 2: Goldman Fristoe Test of Articulation-Second Edition (Goldman & Fristoe, 2000).

^bDEAP: Diagnostic Evaluation of Articulation and Phonology (Dodd et al., 2006).

^cGozzard et al. (2006).

^dIdentified perceptually as inaccurate stress pattern (mismatch between modelled target and child’s production).

^eIdentified perceptually as a pause between sounds and/or syllables within a word.

^fRobbins and Klee (1987).

^gCELF-P2: Clinical Evaluation of Language Fundamentals-Preschool Second Edition (Wiig et al., 2006).

^hPPVT-4: Peabody Picture Vocabulary Test-Fourth Edition (Dunn & Dunn, 2007).

ⁱHearing screen adapted from ASHA (1997).

WNL = within normal limits; LNR = lower than normal range; IS = inconsistent speech.

^{^}Assessment was completed by the child’s private speech pathologist less than 12 months before treatment was administered.

^#Passed on the second test that was administered (date). Failed the first attempt (date).

⁺ = years; months reported.

* = mild.

** = severe.

Table II. Summary of changes to the K-SLP protocol following Gomez, McCabe, Jakielski, Purcel (2018).

Protocol changes	Gomez, McCabe, Jakielski, Purcel, 2018	Modified K-SLP	Rationale for changes
Training	Training provided through models provided by an experienced K-SLP trained clinician, along with limited videos of the treatment process made available by the Kaufman Children’s Centre (refer to Supplemental Material). Minimal training provided to develop proficiency transcribing severely disordered speech.	Enhanced training through additional treatment video examples from the Phase I trial (Gomez, McCabe, Jakielski, & Purcell, 2018), along with role playing between clinicians to practice the K-SLP process and techniques. Training and transcription practice provided to transcribers until a high level of inter-reliability obtained (target 80–85%).	Training was enhanced to improve treatment fidelity and reliability.
Protocol	Wording within the protocol and therapy criterion (i.e. production to time-based criterion) changed during the therapy, reflecting a pilot design (Gomez, McCabe, Jakielski, & Purcell, 2018).	Improved wording of instructions for better clarity. Protocol and therapy criterion stable (i.e. time-based criterion implemented from the first treatment session). The protocol used for this research study is available as Supplementary Material.	We sought to improve treatment fidelity by improving the clarity of instructions in the treatment protocol. Additionally, modifying the within-therapy criterion was important to better engage the children in therapy and to reduce the cognitive burden on the treating clinician.
Therapy progression	To progress from word to phrase level, 80% accuracy had to be achieved on the child’s current level of approximation on at least 12 productions of a word at the level of “independent production” in the cueing hierarchy (c.f. Gomez, McCabe, Jakielski, & Purcell, 2018).	To progress from word to carrier phrase level, the child had to achieve accurate productions on at least 5/6 productions on their current level of approximation with the use of the “oral posture” cue.	These changes were made to reflect the relatively fast progression from word to carrier phrase level in the original K-SLP manual (Kaufman, 2014).
Treatment word selection	Ten words were randomly selected from possible 20 words (two word shape goals) each day.	Five words were randomly selected from each of the two word shape goals, thus ensuring that both word shape goals were targeted each day.	This was done to ensure equal treatment dosage across the two word shape goals.
Feedback	Feedback was faded across each treatment session (i.e. 100% feedback on the first 10 trials, 90% feedback on the subsequent 10 trials, etc.). The average feedback across each session was 55%.	Feedback was faded across each treatment week (i.e. every four sessions). Average feedback across the 12 sessions was 80%.	This change was made to simplify the feedback schedule for the treating clinicians.

Table III. Treated words used in individual therapy sessions.

	Drill therapy targets (words)		Play therapy targets
Billy	Bisyllabic + CV(C)	Polysyllabic	Functional words
	Bottle top	Animal	Stop
	Muddy boot	Domino	Show
	Honey pot	Piano	Outside
	Pony ride	Tomato	Help
	Panda bear	Banana	Push
	Dirty hat	Potato	Open
	Paddle boat	Lavender	Purple
	Nobody	Table top	Don’t
	Tummy hurt	Tornado	Finish
	Happy day	Bicycle	Sleeping
Sam	Bisyllabic + CV (C)	Polysyllabic	Functional words
	Bottle top	Animal	Open
	Muddy boot	Domino	Stop
	Honey pot	Piano	Outside
	Pony ride	Tomato	Help
	Panda bear	Banana	Little
	Dirty hat	Potato	Purple
	Paddle boat	Lavender	Yellow
	Table top	Nobody	Kick
	Tummy hurt	Tornado	Catching
	Happy day	Bicycle	seven
Max	Bisyllabic	Polysyllabic	Functional words
	Napkin	Animal	Stop
	Candle	Domino	Shut
	Tablet	Piano	Close
	Finger	Tomato	Slowly
	Music	Banana	Faster
	Chicken	Potato	Yellow
	Panda	Lavender	Please
	Handle	Nobody	Play
	Pumpkin	Tornado	Finish
	Pencil	Bicycle	Five
James	Bisyllabic	Polysyllabic	Functional Words
	Napkin	Animal	Out
	Candle	Domino	Off
	Tablet	Piano	Open
	Finger	Tomato	Shake
	Music	Banana	Purple
	Chicken	Potato	Yellow
	Panda	Lavender	White
	Handle	Nobody	Play
	Pumpkin	Tornado	Help
	Pencil	Bicycle	Show

Note. Drill therapy refers to the words included in the 8 minute portion of the practice phase, while the play therapy words refer to the targets included during the 2 minute play time (at the end of each 8 minute drill therapy block).

Figure 1. Billy’s percent phonemes correct (PPC) for experimental probe data.

Table IV. Summary of percentage non-overlapping data (PND) and improvement rate difference (IRD) as measures of effect size for treated, control, and untreated words.

Goals	Analysis	Billy (%)	Sam (%)	Max (%)	James (%)
Treated and control words
Goal 1	PND	**100	20	**100	20
	IRD (A1B1)	**100	−17	**100	−67
	IRD (A1A2)	**100	−100	**100	−67
	IRD (B1A2)	17	−100	−50	−67
Goal 2	PND	*80	40	**100	40
	IRD (A1B1)	17	−33	**100	17
	IRD (A1A2)	**100	0	**100	0
	IRD (B1A2)	**100	−33	**100	−100
Goal 3	PND	40	20	**100	40
	IRD (A1B1)	−100	−17	**100	−17
	IRD (A1A2)	0	−100	**100	−67
	IRD (B1A2)	−33	−100	−17	−67
Control	PND	20	60	20	0
	IRD (A1B1)	−33	17	0	0
	IRD (A1A2)	0	33	33	0
	IRD (B1A2)	*67	−17	33	0
Untreated words
Goal 1	PND	**100	60	**100	0
	IRD (A1B1)	**100	−17	**100	−100
	IRD (A1A2)	**100	−33	**100	−100
	IRD (B1A2)	−100	−100	−33	−100
Goal 2	PND	*80	60	60	60
	IRD (A1B1)	**100	**100	−50	**100
	IRD (A1A2)	0	33	33	−33
	IRD (B1A2)	−67	−100	−17	−100
Goal 3	PND	40	*80	**100	0
	IRD (A1B1)	−67	−50	**100	−100
	IRD (A1A2)	−33	**100	**100	−100
	IRD (B1A2)	−33	−17	−67	17

Note. Positive scores are indicative of improvement, whilst negative scores are indicative of deterioration of some to most data points to baseline levels of accuracy.

A1B1 compared the pre-treatment baseline accuracy to treatment phase accuracy.

A1A2 compared the pre-treatment baseline accuracy to the post-treatment phase accuracy.

B1A2 compared the treatment phase accuracy to the post-treatment phase.

**Very effective intervention effect; *effective intervention effect (Rakap, 2015).

Figure 2. Sam’s percent phonemes correct (PPC) for experimental probe data.

Figure 3. Max’s percent phonemes correct (PPC) for experimental probe data.

Figure 4. James’s percent phonemes correct (PPC) for experimental probe data.

Table V. Summary of assessment results from baseline and 1 month post-treatment follow-up speech assessments.

	GFTA-2 (standard score/percentile)		Polysyllabic word list (PPC %)		Inconsistency (%)
Participant	Pre-treatment	Post-treatment	Pre-treatment	Post-treatment	Pre-treatment	Post-treatment
Billy	64/4	81/12	55	56	83*	75*
Sam	88/21	70/4	59	54	76	80
Max	83/14	85/16	54	57	76*	63*
James	56/1	57/2	46	45	80	44

Note. Inconsistency percentages would be expected to decrease over time with intervention to demonstrate improved and stabilised motor plans/programs for speech.

GFTA-2 = Goldman Fristoe Test of Articulation-Second Edition (Goldman & Fristoe, 2000); PCC = percent phonemes correct.

*Only 24 of the 25 Diagnostic Evaluation of Articulation and Phonology (DEAP; Dodd et al., 2002) words were administered due to the assessment clinicians’ oversight.

Table

Trial #	Target from data sheet	Clinician judgement	Fidelity clinician judgement	Decision score (1/0)	Feedback provided?	Feedback score (1/0) i.e. was feedback scheduled for the trial?	Repetition elicited? 1 2		Repetition fidelity score (1/0) i.e. was repetition elicited when it was scheduled?
1					Y / N
2					Y / N
3					Y / N
4					Y / N
5					Y / N
6					Y / N
7					Y / N
8					Y / N
9					Y / N
10					Y / N
11					Y / N
12					Y / N
13					Y / N
14					Y / N
15					Y / N
16					Y / N
17					Y / N
18					Y / N
19					Y / N
20					Y / N

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