Table 3.
Overview of the characteristics and findings from the identified randomized controlled trials.
| Study | Participants | Intervention | Dependent Variables | Outcomes | Predictors | ||
|---|---|---|---|---|---|---|---|
| PRT | Other | PRT | Other | ||||
| Barrett et al. (56) | N = 12; Mage = 35.75 mths, SD = 9.31; 8.33% Female; Ethnicity: White (75%), Latino (17%), Asian (8%), Multi-racial (0%). |
N = 9; Mage = 38.22mths, SD = 9.78; 11.1% Female; Ethnicity: White (45%), Latino (22%), Asian (11%), Multi-racial (22%). |
PRISM Model: Setting: clinician delivered plus parental component; Duration: 6 mths Intensity: up to 10 hrs/w (8 hrs clinician one-on-one; 2 hrs parent education); Mean intensity = 6.81 hrs (25% families met the threshold of 80% completion of all possible treatment hours). | Waitlist | Parent-child play interaction coded for: (i) Parent social bids; (ii) Child social responsiveness; (iii) N total words; (iv) N different words; (v) MLU. | (i) Parent social bids: no significant changes; (ii) Child social responsiveness: significant improvement in PRT (an increase from responsive to 67% of opportunities pre- to 80.9% post-treatment) but not waitlist group; (iii) and (iv) N total and different words: not a significant increase in PRT group and no changes in waitlist; (v) MLU: significant increased in PRT but not waitlist group. |
The minimally verbal subgroup (N = 5) showed large effect sizes (but not statistically significant) for all pre- to post-treatment comparisons. Although at the level of total PRT group initial child responsiveness with caregivers did not show significant association with any of the subsequent outcomes, it was significantly associated with gains in total words, and although no reaching statistical significance, it was moderately associated with gains in different words and mean length of utterance. |
| de Korte et al. (57) | N = 22; Mage = 11.87 yrs, SD = 1.62; 27.3% Female; Ethnicity: not reported. |
N = 22; Mage = 11.70 yrs, SD = 2.11; 31.8% Female; Ethnicity: not reported. |
PRT: Setting: seven parent-child sessions, three parent-only sessions, two sessions with involvement of the teacher; Duration: 12 weeks; Intensity: 45 mins per sessions, 90 min per sessions where teachers were involved. | TAU. | Primary: SRS total score; Secondary: CGI; ADOS-2; VABS ABC and subscale scores; Brief Problem Monitor-Parents; Parenting Stress Questionnaire. | (i) SRS total score: significantly higher reduction in PRT vs. TAU on parent-report but not teacher report; (ii) Proportion of responders on CGI-I higher in PRT vs. TAU, however, NS at 12-week and reaching significance at 20-week follow-up (but NS after correction for multiple comparisons); (iii) ADOS-2: NS between PRT vs. TAU; (iv) VABS: NS for VABS ABC, significant improvement in socialization score in PRT vs. TAU; (v) Brief Problem Monitor-Parents: significantly higher reduction on total score in PRT vs. TAU; (vi) Parenting Stress Questionnaire: NS between PRT vs. TAU. |
No significant correlations between age, sex and IQ with SRS outcomes; lower symptom severity on ADOS CSS total score associated with higher improvements in the SRS-2 scores in PRT (but not TAU) group. |
| Gengoux et al. (39) | N = 23; Mage = 49.5 mths, SD = 11.2; 9.5% Female; Ethnicity: White (26%), Latino (17%), Asian (8.7%), Multi-racial (4%), Other (8%). |
N = 20; Mage= 47.2 mths, SD = 10; 15% Female; Ethnicity: White (30%), Latino (5%), Asian (60%), Multi-racial (0%), Other (5%). |
PRT-P: Setting: clinician in home-delivered plus parental component; Intensive phase: Duration: 12 weeks; Intensity: 10h/pw in home clinician delivered; 1h/pw parent training; Maintenance phase: Duration 12 weeks; Intensity: 5h/pw in home clinician delivered; 1h/pm parent training. | DTG | Primary: N functional utterances during 10-min SLO (baseline, week 12 and 24); Secondary: BOSCC; CDI; VABS; PLS-5; MSEL; SRS-2; CGI-S and CGI-I. | Primary: Significantly higher increase in the number of utterances in PRT vs. DTG at both 12 and 24 weeks (primarily driven by the nonverbally prompted utterances); Secondary: Significant treatment effect for BOSCC total and SC scores, CDI (words produced out of 396 and 680), CGI-S, CGI-I (24 months); No treatment effects for PLS-5, MSEL, SRS-2 and VABS. |
SLO: age, sex, and baseline characteristics did not predict treatment response; BOSCC: total score: association with lower MSEL scores (predominantly NVIQ). |
| Hardan et al. (38) | N = 25; Mage = = 4.1 yrs, SD = 1.2; 24% Female; Ethnicity: not reported. |
N = 23; Mage = 4.1 yrs, SD = 1.3; 6 Female; Ethnicity: not reported. |
PRT-G; Setting: parent delivered; Duration: 12 weeks; Intensity: Eight 90 minute visits (4-6 parents, 1–2 clinicians); Four visits-parent-child dyads with a clinician (60 min). | PEG Duration: 12 weeks; Intensity: Ten 90 minute visits (4-6 parents, graduate student); Two visits-parent-child dyads with a psychologist (60 min). |
Primary: N of functional utterances during 10-minute SLO (baseline, week 6 and 12) Secondary: CDI; VABS; CGI-S and CGI-I; SRS; PLS-4. | Primary: In both PRT-G and PEG groups significant improvements in the total number of utterances, improvement higher in PRT-G vs. PEG; Treatment effect most pronounced for imitative and non-verbally prompted utterances, NS for unintelligible and verbally prompted utterances; Fidelity modified treatment effects for total and imitative but not verbally, nonverbally prompted and spontaneous utterances. Secondary: Significant treatment effect for VABS Communication (expressive and receptive) scores, CGI-S and CGI-I scores but not CDI mean length of longest utterance and total words out of 396 and 680, PLS-4 nor SRS total raw score. |
Higher age and IQ associated with more total utterances (NS effects for sex); baseline MSEL visual reception a significant predictor of total and imitative utterances. Treatment effect not modified by baseline PLS, CDI nor SRS scores. |
| McDaniel et al. (58) | N = 20; Mage = 49.85 mths, SD = 11.92; 12% Female; Ethnicity: White (28%), Latino (7%), Asian (56%), Native Hawaiian (2%), Multi-racial/other (7%). |
N = 20 Mage = 46.85 mths, SD = 9.66; 12% Female, Ethnicity: White (30%), Latino (5%), Asian (60%), Multi-racial (0%), Other (5%). |
PRT-P: Setting: clinician delivered plus parental component; Intensive phase: Duration: 12 weeks; Intensity: 10h/pw in-home clinician delivered; 1h/pw parent training; Maintenance phase: Duration 12 weeks; Intensity: 5h/pw in-home clinician delivered; 1 h/pw parent training. | DTG | Reciprocal vocal contingency derived through an automated process from daylong audio samples from the child's natural environment. | No significant group differences at baseline and 12 weeks but PRT-P had significantly higher-ranked reciprocal vocal contingency scores at 24 weeks (moderate effect size). | NR |
| Mohammadzaheri et al. (59) | N = 15; Mage = 110.67 mths, SD = 18.71; 40% Female; Ethnicity: Iranian (100%). |
N = 15; Mage = 110.47 mths, SD = 18.62; 40% Female; Ethnicity: Iranian (100%) |
PRT Setting: clinician delivered Duration: 3 months; Intensity: 60 min per session (child-clinician, parents not present), 2 sessions/pw. | ABA: Setting: clinician delivered Duration: 3 months; Intensity: 60 min per session (child-clinician, parents not present), 2 sessions/pw. |
MLU; CCC. | PRT group significantly higher MLU and CCC gains than ABA group | NR |
| Mohammadzaheri et al. (33) | N = 15; Mage = 110.67 mths, SD = 18.71; 40% Female; Ethnicity: Iranian (100%). |
N = 15; Mage = 110.47 mths, SD = 18.62; 40% Female; Ethnicity: Iranian (100%) |
PRT Setting: clinician delivered Duration: 3 months; Intensity: 60 min per session (child-clinician, parents not present), 2 sessions/pw. | ABA: Setting: clinician delivered Duration: 3 months; Intensity: 60 min per session (child-clinician, parents not present), 2 sessions/pw. |
Disruptive behavior (defined as any behavior that disrupted the session) coded from the videotaped fist and last session (first, middle and last 8 min). | At baseline, PRT group had a significantly higher level of disruptive behaviors; both groups showed a significant decrease in disruptive behaviors with the magnitude of reduction more pronounced in PRT than ABA group (9.9 vs. 1.2 min). | NR |
| Nefdt et al. (60) | N = 13; Mage = 38.92 mths, SD = 14.57; Ethnicity: not reported in detail, 81% white across both PRT and control group. |
N = 14; Mage = 38.43 mths, SD = 11.20. |
PRT: Self-directed learning program consisting of education material (DVD lasting 1 h 6 min and manual). | Waitlist | Parental measures: (i) Fidelity of implementation (the following five points were scored: presenting clear opportunities, child choice, | PRT group had significantly higher scores across all dependent variables at posttest that the waitlist group; All parents who completed the self-directed learning program reported high ratings of satisfaction. |
NR |
| immediate contingent consequences, natural reinforces, reinforcing verbal attempts and correct verbal responses); (ii) Language opportunities; (iii) Observed parental confidence Child measures: Functional verbal utterances | |||||||
| Schreibman and Stahmer (53) | N = 20; Mage = 29.5 mths, SD = 6.9 10% Female; Ethnicity: not reported. |
N = 19; Mage = 28.9 mths SD = 4.2; 15.8% Female; Ethnicity: not reported. |
PRT used by parents and therapists to target the development and spontaneous use of functional spoken language. For the first 15 weeks, there were biweekly, 2h parent education sessions (with their child) in the laboratory and additional 2 h/pw child sessions in the home (trained undergraduate student therapists); Additional 8 weeks consisted of five 2 h/pw parent educations sessions and two 2 h/pw in the home with the child. |
PECS used by parents and therapists to teach children to use picture icons to communicate; For the first 15 weeks, there were biweekly, 2h parent education sessions (with their child) in the laboratory and additional 2 h/pw child sessions in the home (trained undergraduate student therapists); Additional 8 weeks consisted of five 2 h/pw parent educations sessions and two 2 h/pw in the home with the child. |
Spoken Language (MSEL Expressive language scale); Spoken Vocabulary (EOWPVT and CDI); Adaptive Communication (VABS); Parent Satisfaction. |
Children in both intervention groups demonstrated increases in spoken language skills, with no significant difference between the two conditions. Seventy-eight percent of all children exited the program with more than 10 functional words; Parents were satisfied with both PRT (rating 5.7 out of 7) and PECS (rating 6 out of 7). |
NR |
| Vernon et al. (40) | N = 12; Mage = 35.75 mths, SD = 9.31 8% Female; Ethnicity: White (75%), Latino (17%), Asian (8%), Multi-racial (0%). |
N = 11; Mage = 34.45 mths, SD = 10.08; 18% Female; Ethnicity: White (36%), Latino (27%), Asian (18%), Multi-racial (18%). |
PRISM Model: Duration: 6 mths Intensity: up to 10 h/pw (8 h clinician one-on-one; 2 h parent education); Mean intensity= 6.81h (25% families met the threshold of 80% completion of all possible treatment hours). | Waitlist | Primary: ADOS-2; MSEL Composite; PLS-5 Total; PPVT-4; EVT-3; VABS ABC score. Secondary: MSEL (Visual reception, fine motor, expressive and receptive language); PLS-5 (Auditory and expressive comprehension); VABS (Communication, daily living, socialization, motor skills). | For the treatment group, statistically significant changes from baseline were found for all the primary outcomes apart from the EVT-3 and VABS ABC; For the secondary outcomes, there were significant changes for MSEL Visual reception, fine motor and expressive but not receptive language scores, significant changes for VABS communication but not other VABS subscales, no changes for PLS-5 subscales were found. No significant changes from baseline were observed on any measures in the waitlist group for primary outcomes. For secondary outcomes, significant pre-post changes were observed in the Mullen scale of fine motor skills. |
NR |
ADOS, Autism Diagnostic Observation Schedule; BOSCC, Brief Observation of Social Communication Change; CDI, MacArthur-Bates Communicative Development Inventories; CGI, Clinical global impression; DTG, Delayed treatment group; EOWPVT, One-Word Picture Vocabulary Test; MLU, Mean length of utterance; MSEL, Mullen Scales of Early Learning; NR, not reported; NS, Not significant; NVIQ, Non-verbal intelligence quotient; PECS, Picture Exchange Communication System; PEG, Psychoeducation group; PLS, Preschool Language Scale; PRISM, Pivotal Response Intervention for Social Motivation; PRT, Pivotal Response Training; SC, social and communication; SI, social interaction; SLO, Structured language observation; SMD, standardized mean difference; SRS, Social Responsiveness Scale; VABS, Vineland Adaptive Behavior Scales.