Parent-delivered early language intervention for young children with Down syndrome: assessing trial feasibility

Approved 12/07/2023, University of Manchester Research Ethics Committee 1 (Research Governance, Ethics and Integrity; 2nd Floor Christie Building; The University of Manchester, Manchester, M13 9PL, United Kingdom; Nil known; urec1@manchester.ac.uk), ref: 2023-16509-30334

The feasibility of a future definitive trial of the PACT-DS programme, assessed using:
1. The number of participants interested in taking part, consented, completed screening, eligible, and randomised [within 18 months of start date].
2. Adherence to and acceptability of the PACT-DS intervention via measures of attendance at training, number of intervention sessions completed, number of participants withdrawing from intervention, and intervention fidelity as well as records of email and telephone support provided to families, surveys and qualitative interviews [within 33 months of start date]
3. The acceptability and experience of the trial process to participants, including randomisation and completion of outcome measures [within 33 months of the start date].
4. The optimal primary outcome measure in a future trial, determined by assessing the performance of selected candidate primary outcome measures with respect to the level of acceptability to participants (completion rates, perceived burden) and reliability [within 33 months of start date].
5. Estimated sample size for a future trial by measuring participant withdrawal, data completeness at follow-up (participant attrition) and group differences and 95% confidence intervals for child language measures at immediate and delayed follow-up [within 33 months of start date]
6. The potential benefits and costs in a future trial including benefits for child and parent outcomes and costs of intervention including intervention materials and resources and staff time for training and support (in line with recent cost guidance from the Education Endowment Foundation) [within 33 months of start date].

Progression to definitive trial will be informed by the results of three main progression criteria:
Recruitment: at least 50% of the proposed sample (n = 28-30) recruited to (i.e. take up an offered place in) feasibility study = Green; 40-49% = Amber; below 40% = Red.
Intervention adherence: will be based on the experimental group delivering the programme; i.e. 50%+ of the intervention group complete =>17 weeks of the programme (the average completion rate in Burgoyne et al., 2018) = Green; 40-49% = Amber; below 40% = Red.
Retention will be based on the proportion of the recruited sample that completes delayed post-testing (i.e. children with quantitative data at delayed post-test); i.e. 80%+ = Green; 50-79% = Amber; <50% = Red.

The outcome measures that will be evaluated within this feasibility study are listed below. The following measures are all collected at baseline (prior to randomisation) and at immediate post-test (immediately following the 30-week intervention phase) and follow-up post-test (6 months after the immediate post-test) with all participants (in both groups) with the exception of the child emergent literacy measure (assessed at 6-month follow-up only):

Child Language:
1. Child vocabulary, assessed using the parent-completed Reading Communicative Development Inventory
2. Child expressive and receptive vocabulary, assessed using the Expressive and Receptive One Word Picture Vocabulary Tests
3. Child expressive information and grammar, assessed using the Action Picture Test
4. Child Narrative Skills, assessed using a story retell task
5. Child intervention vocabulary knowledge, assessed using a researcher-developed task
6. Parent-child interaction, providing measures of child language and parent measures (e.g. responsiveness, use of language boosting strategies), assessed using video recordings of parents and children sharing books and playing together

Child Emergent Literacy (assessed only at 6-month follow-up):
7. Child emergent literacy, assessed using the York Assessment of Reading for Comprehension (assessed at 6-month follow-up only)

Home Learning Environment:
8. Home Learning Environment, assessed using a Home Learning Environment questionnaire

Child Executive Functioning:
9. Child executive functioning, assessed using the Behaviour Rating Inventory of Executive Functioning – Preschool

Parent Measures:
10. Parent Knowledge, Skills, and Confidence in relation to language development, as assessed through a questionnaire based on the Theoretical Domains Framework
11. Parent anxiety and depression, as measured by the Hospital Anxiety and Depression Scale (HADS)
12. Parental quality of life as assessed by the Adult Carer Quality of Life Questionnaire (AC-QoL)