A Parent-Coaching Intervention to Promote Community Participation of Young Children With Developmental Disability
Phase: NA
Conditions: Developmental Disability
Sponsor: The Hong Kong Polytechnic University

 
 
 
Study Protocol and Statistical Analysis Plan 
 
Title: Occupational Performance Coaching With Parents of Young Children With 
Developmental Disability 
 
 
NCT number: NCT04796909 
 
 
Document date: 22 July 2020 

1 
Introduction 
High rates of restricted community participation have been reported in young children 
with developmental disabilities. Occupational performance coaching (OPC), grounded in 
self-determination theory, aims to facilitate children’s participation in life situations through 
coaching parents. However, there have been limited randomized controlled trials 
demonstrating the efficacy of OPC, especially with a specific focus on children’s community 
participation. The proposed study is the first step in evaluating the feasibility and 
acceptability of conducting a pilot randomized controlled trial of OPC in Hong Kong and 
testing its initial efficacy (in comparison to parent consultation) in promoting children’s 
community participation. 
In this document, we report a study protocol that will be used in the Phase 1 
Randomized Control Trial (RCT) which aims to evaluate the feasibility of conducting an 
RCT of OPC in Hong Kong, the acceptability of the coaching intervention, and the initial 
efficacy of OPC on promoting children’s community participation. 
 
2 
Materials and Methods 
2.1 
Trial Design 
We propose a two-arm parallel, double-blind design for this Phase 1 RCT of OPC. 
Parents of young children with DD will be randomly assigned to the intervention group 
(receiving OPC), and the control group (receiving parent consultation) and will be blinded to 
the group type that they are assigned to. Parent consultation is chosen as the 
component-equivalent control treatment, because it is a common approach used by 
rehabilitation therapists to improve children’s adaptive behavior and parenting skills. 
Meanwhile, both groups will continue to receive usual care during the study period. The trial 
design is illustrated in Figure 1. The present protocol was prepared according to the 
recommendation for good practice in RCT feasibility and pilot design. 
2.2 
Study Setting and Participants 
The RCT will be conducted in Hong Kong across three major geographical regions 
(Hong Kong Island, Kowloon, and New Territories). The target population will comprise 
families with young children awaiting or receiving early intervention services. To be eligible 
for the study, participants will have to (a) be one/both parent(s) of a child aged 2–6 years old 
who have been clinically diagnosed with a DD (including but not limited to intellectual 
disability, developmental delay, or autism spectrum disorder) given by 
pediatricians/psychiatrists; (b) be the child’s main caregiver who has a long-term parenting 

role with at least 50% of caregiving responsibilities; (c) be able to converse in Chinese; and 
(d) have the desire to improve their child’s participation in four community activities that are 
selected from the Young Children’s Participation and Environment Measure (YC-PEM, 
detailed later).  
Participants will be excluded if their child has DD combined with physical impairment 
(e.g., amputation, cerebral palsy, spina bifida) or sensory impairment (e.g., blindness, 
deafness). This is because the support and resources needed to improve community 
participation for these children may differ from those for children with DD without 
physical/sensory constraints. 
2.3 
Sample Size 
The sample size was calculated using Morgan and Case’s formula with the following 
set-up: type I error of 0.05, power of 0.90, 1-to-1 random allocation, and variance ratio of 
0.44, using a conservative assumption for the compound symmetry correlation structure. A 
large effect size (Cohen’s d) of 0.80 was determined based on the pooled effect sizes derived 
from our previous study and a recent RCT. Therefore, a minimum sample size of 30 
participants will be required in this pilot RCT to test for 2 × 3 mixed design analysis of 
covariance (i.e., the number of two groups with three repeated measurements, adjusted for 
individual differences in baseline assessments). Allowing for an attrition rate of 40% that was 
observed in the previous study, a total of 50 parent-child dyads (25 in each group) will be 
recruited. 
2.4 
Recruitment Method 
Participants will be recruited from early intervention services within three 
non-governmental organizations in Hong Kong. Occupational therapists who work in each 
service will assist in the initial screening of potentially eligible families of children receiving 
services. They will then provide the parents of interest with the study information sheet and 
consent form. Once the signed consent forms are returned, a research assistant who oversees 
the trial will contact parents by phone to further screen for study participation eligibility. 
Posters and social media will be used to recruit families of children who are awaiting early 
intervention services. Parents of interest will be asked to contact the same research assistant 
for screening and, if eligible, to complete the consent forms. 
2.5 
Randomization and Blinding 
Block randomization stratified by engagement in early intervention services (awaiting vs. 
receiving) based on the 1-to-1 allocation ratio will be used to assign participants to the 
intervention or control group. The randomization sequence will be computer-generated, and 
allocation will be completed by another research assistant not associated with the study. 

Participants and independent outcome assessors will be blinded. 
2.6 
Intervention and Control Treatment 
2.6.1 Intervention Treatment: Parent Coaching (OPC) 
The OPC intervention comprises three components defined as the enabling domains: (1) 
connect – building parents’ trust in the coach by using verbal and nonverbal strategies such as 
listening, empathizing, and partnering; (2) structure – building parents’ competence by 
adopting a problem-solving framework of setting goals, exploring options, planning action, 
carrying out plans, checking performance, and generalizing; and (3) share – building parents’ 
autonomy by reciprocally exchanging information between the coach and parents with an 
emphasis on eliciting parents existing knowledge. In particular, collaborative performance 
analysis is used to explore the options for a particular goal. In this collaborative performance 
analysis, the coach follows four steps: (a) identify parents’ perception of what currently 
happens, (b) identify what they would like to happen, (c) explore barriers and bridges to the 
desired performance, and (d) identify their needs to take actions to achieve goals. Throughout 
these steps, parents are guided to find strategies to facilitate their children’s performance in 
order to support goal achievement.  
In this pilot RCT, we propose that the OPC intervention will consist of four to eight 
weekly (or fortnightly) sessions in correspondence with the number of goals identified by 
parents and the progress of the goal achievement. Each session will last 30 minutes to one 
hour. Depending on parents’ needs, coaching sessions will be delivered in person with one or 
both parent(s) in therapeutic/office rooms located at participating early education and training 
centers, special child care centers, university campuses, or via telephone or other 
communication applications (e.g., Zoom or WhatsApp). Parents will be allocated to the same 
coach throughout the intervention period, and the coach will not be the treating therapist of 
their child. Because OPC focuses on coaching parents, children’s attendance at the coaching 
sessions will be at the parents’ discretion.   
Coaches who deliver OPC will be occupational therapists working in participating 
non-governmental organizations who have at least two years of experience working with 
children/parents. A total of 29 therapists attended a 16-hours online training workshop 
delivered by the OPC developer (i.e., the last author) in March 2020. The workshop involved 
the translation of coaching techniques to participants using case examples, video, live 
demonstrations, role play, discussion, and active planning for implementation in specific 
practice settings. Further, 14 of the therapists attended a four-hours follow-up training by the 
OPC developer in May 2020, and eight of them were mentored for various hours relating to 
intervention fidelity by the first author, who is a qualified OPC trainer. In total, the training 
for each coach was at least 24 hours cumulatively, and they will be dropped if they do not 

demonstrate >80% fidelity in the practice of one real case prior to study commencement. This 
is the minimum requirement recommended in the OPC manual for conducting related 
research projects. Once the intervention begins, the researchers will provide the coaches with 
continuous supervision and mentoring through individual meetings and/or Google forums 
when their self-rated fidelity of OPC in any sessions does not achieve 80%. All coaching 
sessions will be audio-recorded to monitor intervention fidelity. 
2.6.2 Control Treatment: Parent Consultation 
Parents who are randomized to the control treatment will receive consultation regarding 
community resources from occupational therapists or occupational therapy students who are 
not involved in OPC training or meetings in the study. A toolbox of community resources has 
been developed by the research team by identifying public playgrounds, play groups, and 
sports programs sponsored by non-governmental organizations or government from the 
website of the Leisure and Cultural Services Department (www.lcsd.gov.hk/en/). It also 
included generic supportive strategies for parents of children with disabilities, as drawn from 
the existing literature. Occupational therapists or master of occupational therapy students who 
have studied rehabilitation psychology and fundamental occupational therapy subjects will 
use the toolbox to provide parents with available environmental resources and strategies to 
enhance the community participation of their child with DD, followed by an understanding of 
the current situation and the identification of problems encountered by parents. The direct 
informing approach will be used to instruct parents about the availability of environmental 
resources close to their living areas and what they can plan to do by using possible supportive 
strategies. In addition, information about child disability and/or developmental milestones 
may be provided if needed. However, the OPC key elements, such as parents’ involvement in 
the action-reflection process and collaborative performance analysis will be avoided in the 
consultation. 
The consultations will be conducted for four to eight weekly/fortnightly sessions 
depending on the parents’ needs, and each session may last 30 minutes to one hour. The 
consultations will be delivered in person or in tele-format at the parents’ discretion. Prior to 
the study, occupational therapists and occupational therapy students will be trained by the 
first author in the use of the toolbox. A two-hour training session will be held including the 
introduction of strategies and resources included in the toolbox and the procedure to provide 
consultation, followed by role-play practice. They will be supervised regularly in monthly 
meetings throughout the study period. Parents will be allocated to the same trained therapists 
or students for consultation during the study period. 
2.6.3 Usual Care 
Children who are randomized to either the intervention or control group will continue to 
receive usual care. Depending on individual needs or status, usual care may include (a) 

waiting to access early intervention services; (b) services provided by the training/care 
centers, such as occupational therapy, physiotherapy, and speech therapy on a 
weekly/monthly basis; and (c) private therapy. Of the early intervention services, 
occupational therapy in Hong Kong focuses on improving children’s fundamental skills (e.g., 
fine motor, sensory integration, visual perception, and pre-writing) and self-care 
abilities—mostly through direct training on children. Thus, it will have a minimal effect on 
children’s community participation. To understand the variability in usual care received by 
children between the intervention and control groups, parents will be asked to complete a 
therapy-activity log during the study period, which will record the type(s) and duration of 
service(s) children receive on a weekly basis. 
2.7 
Outcome Measures 
2.7.1 Assessment timing 
This pilot RCT will use four assessment points similar to the design of Graham et al.’s 
study. The four time points are: 5–6 weeks before intervention (time 0 for baseline 
assessment), 1–2 weeks before intervention (time 1 for pre-intervention assessment), 1–2 
weeks after intervention (time 2 for post-intervention assessment), and 8–9 weeks after the 
intervention (time 3 for follow-up assessment).  
2.7.2 Study assessments 
2.7.2.1 
Feasibility of the Trial 
The feasibility of the trial will be evaluated using five indicators (recruitment, retention, 
adherence, blinding success, and fidelity) with predetermined criteria, as shown in Table 1. In 
particular, the OPC Fidelity Measure Version 3.0 will be used by the first author to rate the 
audio recordings of the eight selected coaching sessions to verify the intervention fidelity of 
each coach. The eight sessions that will be selected will include the first participants’ first two 
sessions and then four randomly selected sessions from the remaining sessions of the first two 
and other participants who are coached by the coach. 
2.7.2.2 
Acceptability of OPC 
The acceptability of the OPC intervention will be assessed through semi-structured 
interviews with parents at time 2 (i.e., 1–2 weeks after the intervention) and with coaches at 
the end of the study. Parents will be asked about their satisfaction with the coaching sessions 
(e.g., relationship with the coach, schedule, and duration), experience in being coached (e.g., 
what they have learned, what they like most/least, and the challenges experienced), and the 
perceived impact of OPC on children’s participation in community activities. Coaches will be 
interviewed to evaluate their experience of delivering OPC intervention (e.g., perceived 

effectiveness, challenges, optimal coaching schedule/duration, and opinions on cultural 
suitability). 
2.7.2.3 
Initial Efficacy of OPC 
2.7.2.3.1 Primary Outcome Measures 
Canadian Occupational Performance Measure (COPM). The COPM will be used to 
measure parents’ perceptions of children’s participation in specific community activities. This 
measure is selected for use because it can identify individualized problems in participation in 
occupations and then help to formulate goals related to child participation through 
semi-structured interviews. In the interview, parents are further prompted to rate their child’s 
performance and their satisfaction with the current status on a 10-point Likert scale (1 = not 
good/satisfied at all and 10 = optimal performance/satisfaction). High scores indicate greater 
children’s participation performance and parents’ satisfaction. In this pilot RCT, we propose 
that parents’ identified goals will not be limited to the community participation but will also 
be extended to other life areas. An adequate internal consistency (Cronbach’s α = 0.73–0.88) 
of the COPM has been reported. The prioritized problems using the COPM in parents of 
children with disabilities were also found to be corresponding with specific items in the 
Pediatric Evaluation of Disability Inventory, demonstrating construct validity of the COPM.    
Young Children’s Participation and Environment Measure (YC-PEM). The 
YC-PEM will be used to capture children’s overall community participation patterns. This 
measure is selected because it is a parent report questionnaire that can be used for young 
children with various disabilities. The YC-PEM also has a community section that includes 
11 participation items across four broad categories of neighbourhood and community outings, 
classes and groups, community-sponsored activities, and recreational activities and trips. In 
each item, parents are asked to rate: (a) how often their child has participated in the past four 
months using an 8-point Likert scale (0 = never and 7 = once or more each day); (b) how 
involved the child is during participation using a 5-point Likert scale (1 = not very involved 
and 5 = very involved); and (c) parental desire for change in the child’s participation (yes/no 
and, if yes, six nominal options for the type of desired change can be selected). Total scores 
are generated by averaging all items in the participation frequency and involvement 
dimensions. High scores indicate greater children’s participation frequency and involvement. 
The YC-PEM participation scale has acceptable internal consistency (α = 0.64–0.78) and 
test-retest reliability (intraclass correlation coefficients [ICC] = 0.82–0.89). Moreover, it 
demonstrates known-group validity between children with and without disabilities and 
convergent validity by correlating with functional performance of children with disabilities.  
2.7.2.3.2 Secondary Outcome Measures 
Parenting Sense of Competence Scale (PSOC). The PSOC is a parent report 

questionnaire to obtain parents’ perceptions of their parenting role, and this scale is selected 
because it will help to examine whether parents who receive OPC will have improved 
parenting competence. The PSOC has two dimensions: efficacy (eight items) and satisfaction 
(nine items). Parents are asked to rate each item on a 6-point Likert scale (6 = strongly 
disagree and 1 = strongly agree). Total scores are generated by summing all items in each 
dimension (after reversing the scores of some items). High scores indicate greater 
competence and satisfaction with parenting, respectively. The PSOC has demonstrated good 
internal consistency (α = 0.77–0.80) and test-retest reliability (ICC = 0.82–85). 
Depression, Anxiety, and Stress Scale-21 (DASS-21). The DASS-21 is a self-report 
questionnaire that includes 21 items assessing people’s negative emotional states of 
depression, anxiety, and stress (seven items in each subscale). In the proposed RCT, the use 
of the DASS-21 is determined because it can be completed by parents to provide insight into 
the beneficial impact of OPC on promoting parents’ emotional states. In the DASS-21, each 
item is rated on a 4-point Likert scale (0 = did not apply to me at all and 3 = applied to me 
very much or most of the time). Total scores are generated by summing all items in each 
subscale, with high scores indicating greater emotional problems. Good internal consistency 
(α = 0.77–0.87) of the DASS-21 has been reported. 
KINDL questionnaire. This questionnaire measures health-related quality of life in 
children and has three age versions with both child and parent reports, including 
Kiddy-KINDL for parents of children aged 3–6 years. Because self-report is difficult for 
young children with DD, the parent-report version of Kiddy-KINDL is determined for use in 
the proposed RCT to explore whether children have improved psychosocial health after the 
OPC intervention. The Kiddy-KINDL comprises 24 items that assess parents’ perceptions of 
their child’s health-related quality of life across physical well-being (four items), emotional 
well-being (four items), self-esteem (four items), family (four items), social contacts (four 
items), and school functioning (four items). The recall period covers the last month in this 
study, and each item is rated using a 5-point Likert scale (0 = never and 4 = all the time). A 
psychosocial health score is generated by summing item scores from the emotional, 
self-esteem, family, and social contacts domains. High scores indicate greater psychosocial 
health. The Kiddy-KINDL has demonstrated acceptable internal consistency (α = 0.70–0.89). 
2.7.2.3.3 Other Exploratory Measures 
Demographic questionnaire. In the proposed RCT, we will design a parent-report 
questionnaire to collect demographic information such as child age and gender, family 
structure, family income, employment of a domestic helper, as well as parents’ age, 
occupation, and education. Parents will also be asked to report the type(s) of clinical 
diagnosis or disability which their child has and rate the severity of their child’s DD as a 
whole using a 4-point Likert scale (1 = very mild and 4 = severe). The demographic and 

clinical information will be used to characterize children and their parents in the intervention 
and control groups for comparison.  
Additionally, we consider that the availability and intensity of early intervention services 
may have an effect on children’s functional performance and participation based on literature. 
Therefore, this questionnaire will also ask parents to report the type(s) and duration of early 
intervention service(s) their child has received in the past month. The information in the total 
number of the early intervention service hours will be categorized and used as a control 
variable adjusted for baseline differences in the analysis of the efficacy of OPC.  
Pediatric Evaluation of Disability Inventory Computer-Adaptive Tests (PEDI-CAT). 
The PEDI-CAT is a parent-report, computer-based assessment of children’s functional 
performance across four domains: daily activity, social/cognitive function, mobility, and 
responsibility. In the proposed RCT, we will select the use of the first two domains, operated 
by the speedy feature, for the purpose of exploring the improvement in children’s daily 
activities and social/cognitive function. The speedy feature allows reducing administration 
time by selecting suitable 10–15 items to assess based on the relative difficulty of preceding 
items and parents’ responses to those items (instead of completing a full set of items). In each 
PEDI-CAT item, parents rate their child’s typical performance using a 4-point Likert scale (1 
= unable and 4 = easy). Scaled scores of each domain are derived based on the estimates of 
the placement of individual children along the hierarchical scales that have been calibrated 
using item-response theory in the standardization samples. The PEDI-CAT scaled scores are 
on a 20–80 metric and have been recommended for use to evaluate changes over time. The 
PEDI-CAT has demonstrated excellent agreement with the full-length version (Pearson’s r = 
0.94–0.99) and satisfactory test-retest reliability (ICC = 0.86–0.92). 
Environmental support scale of the YC-PEM. In the community section of the 
YC-PEM mentioned earlier, parents will also be asked to evaluate the impact of the types of 
environmental features (10 items) and resources (seven items) regarding their child’s 
participation in community settings. This scale is selected for use because we would like to 
explore whether parents who receive OPC have higher perceived environmental support for 
their children’s community participation. In the environmental support scale, a 3-point Likert 
scale is used to assess the level of parents’ perceived impact of environmental features (1 = 
usually makes it harder and 3 = no impact/usually helps) and resources (1 = usually no and 3 
= not needed/usually yes) on participation, respectively. Total scores are generated by 
averaging all items on this scale, with high scores indicating greater environmental support. 
This environmental support scale has acceptable internal consistency (α = 0.83) and 
test-retest reliability (ICC = 0.78). 
Session Rating Scale (SRS). The SRS is a four-item visual analog scale that assesses 
therapeutic alliance at the end of each session, and this scale is used because it provides 
insight into the potential mechanism of parents’ intrinsic motivation to enact actions during 

OPC. Each of the four items captures a key dimension of effective therapeutic relationships, 
including respect and understanding, relevance of the goals and topics, approach used in 
therapy, and overall alliance. Parents are asked to place a mark on a 10-cm line nearest the 
pole that best describes their experience with their OPC coach. Total scores are generated by 
summing up the marks made by parents measured to the nearest centimeter on each of the 
four lines. Higher scores indicate greater therapeutic alliance. The SRS has been reported to 
be internally consistent (α = 0.88–0.96) and reliable over time (r = 0.63). 
Health Care Climate Questionnaire (HCCQ). The HCCQ assesses people’s 
perceptions of health care practitioners’ autonomy support in a given program grounded by 
self-determination theory. It consists of 15 items rated on a 7-point Likert scale (1 = strongly 
disagree and 7 = strongly agree). One example item is “I feel that my health-care practitioner 
has provided me with choices and options about regular exercise.” Total scores are calculated 
by averaging all item scores, with higher scores indicating greater autonomy support. The 
HCCQ has been adapted by Chan et al. for use in the physiotherapy context by replacing 
“health-care practitioner” with “physiotherapist” and eliminating the statement of the specific 
program (e.g., regular exercise). In the proposed RCT, we will adopt Chan et al.’s version 
with a slight amendment of the wording to “my coach.” The modified version of the HCCQ 
will allow us to understand parents’ perceptions of the degree to which their coach is 
autonomy supportive (vs. controlling) in coaching them regarding their child’s participation. 
The HCCQ has demonstrated acceptable internal consistency (α = 0.94–0.95) in various 
studies. 
Patient Global Impression of Change (PGIC). This measure is proposed for use, 
because it can provide an indicator of parents’ global impression of whether their child’s 
participation in community activities has been better, about the same, or worse since the start 
of the given intervention. The PGIC includes only one item that is scored on a 7-point Likert 
scale (1 = very much improved and 7 = very much worse). This measure has been reported to 
demonstrate good clinimetric properties. 
2.8 
Data Analysis 
Descriptive statistics will be used to characterize the participants and evaluate the trial 
feasibility according to our a priori success criteria (see Table 1). The t-test (or 
Mann-Whitney U test) and chi-square statistics will be used to test for between-group 
baseline differences. Prior to the efficacy analyses of OPC, the normality of the data for the 
studied variables will be examined and, if the data are not normally distributed, 
transformation methods will be applied.  
To evaluate the acceptability of OPC intervention, interviews with parents and coaches will 
be transcribed and then analyzed separately using qualitative methods. Specifically, thematic 
analysis using a data-driven inductive approach will be used to scrutinize the parents’ 

interview transcripts and interpret their coaching experience as well as perceived impact. 
Thematic analysis is chosen, because it provides a flexible method for identifying, analyzing, 
and reporting patterns (themes) within data without a prior coding scheme. Alternatively, 
coaches’ interview transcripts will undergo conventional content analysis to describe their 
experience in delivering OPC intervention. We choose content analysis because only eight 
coaches will be involved in the proposed RCT and data saturation may not be achieved if 
thematic analysis is used. Two research team members will be involved in the thematic and 
content analyses by following the recommended procedure. To establish the trustworthiness 
of the thematic and content analyses, code-recode, peer checking, and team discussions will 
be used.  
To evaluate the initial efficacy of OPC on the primary and secondary outcomes, we will 
use the repeated-measures analysis of covariance (ANCOVA) by controlling for baseline 
variability at time 0 as well as the variations in treatment dosage and delivery format (e.g., in 
person or tele-format). That is, the repeated-measures ANCOVAs will be used to compare the 
change in the scores of outcome measures across the three time points (at times 1, 2, and 3) 
by controlling for baseline differences and treatment variations. For participation goals 
identified by parents in the COPM, only community-related participation goals will be 
targeted for analysis. Principles of intent-to-treat analysis will be applied and, if participants 
withdraw after the coaching/consultation sessions, their data for subsequent time points will 
be imputed by carrying the last assessment forward. Post-hoc analyses using the Schffé 
method will be performed when the main comparison results are significant. Statistical 
significance will be set at p < 0.05. Estimates of effect sizes with 95% confidence intervals 
will be calculated for each outcome measure.   

TABLE 1: A priori success criteria to assess the feasibility of the trial 
  
Definition 
Success criteria 
Recruitment 
Percentage of eligible families 
agreeing to participate in the study 
≥20% recruitment response rate 
achieved 
Retention 
Percentage of participants who 
complete the trial 
≥60% retention rate achieved 
(i.e., completion of all 
assessments) 
Adherence 
Percentage of coaching sessions 
attended by parents in the 
intervention group 
≥75% adherence rate achieved, 
based on our previous research of 
similar duration (42) 
Blinding success Percentage of parents who guess 
treatment allocation correctly after 
the study 
50% based on the guess of 
treatment by chance (50/50) 
Fidelity 
Degree to which the OPC is 
implemented by coaches as intended
≥80% fidelity on the OPC 
Fidelity Measure Version 3.0 in 
four selected session per coach 
Note: The OPC Fidelity Measure Version 3.0 consists of 18 items across five domains: 
relationship, goal, reflection, analysis and action, client response, and distinguishing. 
Each item is rated on a 3-point Likert scale (1 = low and 3 = high). The percentage 
score will be calculated by dividing the total score by the possible maximum score. 
Higher percentage scores indicate higher fidelity, and the cut-off of sufficient fidelity of 
OPC per session is set at 80%.