Intervention
The intervention is a group-based, dialogic book-sharing programme based on our previous programme [
45,
46,
49]. The intervention consists of 60–90-min sessions run weekly for eight consecutive weeks. The programme is delivered to groups of three to six caregivers and their children. Each session focusses on different and incremental techniques for caregivers to apply during book-sharing. For the first six sessions there is a ‘book of the week’ that the carers take home to share with their child, and that they bring back the following week. In session 7 all the key principles are reviewed, and the child chooses which of the six books they want to take home for that week. During the final, eighth, session, there is a group discussion where caregivers are guided in reflecting on the programme and they discuss plans for continuing with their book-sharing – such as registering at a nearby children’s library or continuing to meet as a group. Session 8 ends with a graduation where caregivers are presented with a certificate of completion, a laminated card with a summary of the key lessons from the programme (on the back of which there is a picture of themselves and their child sharing a book), and a copy of each of the six books used in the programme. Table
1 details the content for each session. For the 6-month period following session 8, the facilitator visits each participant bi-monthly to deliver a new picture book and have a short encouraging conversation with the caregiver about their book-sharing.
Table 1
Summary of intervention session content
1 |
Introduction to Book-sharing
|
Introduction and basic dialogic book-sharing skills part 1 – following the child’s lead, using a lively voice, setting up book-sharing routines |
2 |
Pointing and Naming
|
Basic dialogic book-sharing skills part 2 – pointing and naming, repeating, extending and elaborating on things that interest the child, finding opportunities for praise |
3 |
Naming and Linking
|
Asking ‘where/who/what’ questions, linking book content to the child’s own experience, finding opportunities to use actions (e.g. hugging, eating) |
4 |
Talking about Feelings
|
Helping the child understand the meaning of basic emotion terms: happy, sad, angry, scared. Discussing why book characters feel the way they do, using facial expression and tone of voice to convey a character’s feelings, linking feelings to the child’s own experience |
5 |
Talking about Intentions
|
Discussing why characters feel the way they do, asking what characters are thinking and intending, encouraging the child to be curious about what will come next in the story |
6 |
Talking about Perspectives
|
Helping the child understand that different people can see things differently, know different things, and feel differently about things |
7 |
Summary
|
Reviews of key principles from sessions 1–6 |
8 |
Graduation Event
|
Certificates of completion are presented to participants along with summary take-home cards and a full set of the 6 books (from sessions 1–6). A group discussion about how to remain motivated about book-sharing and how to access children’s books (e.g. registering with the local library). |
For the intervention sessions, caregivers sit in a semicircle facing the facilitator who sits at the front of the room with a laptop on which a PowerPoint is displayed. An area at the back of the room is laid out for the children with a set of soft toys and balls. The first part of each session is a group-based, instructive presentation of the week’s key book-sharing principles. PowerPoint slides are used to deliver particular learning points, accompanied by brief illustrative video clips. Towards the end of the presentation, the facilitator discusses the book of the week with the carers, highlighting how the book can be used at home and providing examples of how to apply the techniques covered in that session.
The second part of the session involves one-to-one mentoring with the facilitator. This takes place in a separate room, where the caregiver is asked to share the book of the week with their child, under the guidance of the facilitator. These sessions last for approximately 10 min, with the final few minutes dedicated to positive feedback and, where considered helpful, modelling of book-sharing techniques. This session also includes a discussion between caregiver and facilitator about the book-sharing home routine, where the facilitator encourages the carer to spend at least 10–15 min a day sharing the book of the week with their child and practising the techniques learned that week.
Intervention facilitators, training and supervision
The intervention is delivered by two isiXhosa-speaking women from Khayelitsha. Both these facilitators have experience delivering book-sharing training to mothers from the community, having been facilitators in our previous trial [
45,
46], as well as in an earlier pilot study [
49]. Each of the two facilitators is supported by an assistant during intervention sessions whose role is to look after the children, who also attend the sessions. The assistants were selected from the community, based on having previous experience working with young children.
Facilitator training for the current book-sharing intervention was held over a 2-day workshop, run by PC, LM and ND. This included a refresher session, when the content of the earlier programme was reviewed, including a review of the accompanying PowerPoint presentation materials and videos. This was followed by instruction on the new programme content and materials. First, the key principles of the new sessions (i.e. those concerning emotions, intentions and perspectives – see Table
1) were explained, and the accompanying illustrative videos viewed. This was followed by discussion between the trainers and facilitators, and any questions or uncertainties were resolved. During these discussions the facilitators also discussed ways in which the key principles of the new material could be explained and demonstrated in a culturally appropriate manner.
The second part of the facilitator training covered the one-to-one sessions where parents practise book-sharing with their children and receive feedback from the facilitator. This training specified the role that the facilitator needs to play during these sessions, covering principles of sensitive instruction, modelling, and providing positive support. Additionally, facilitators were instructed on how to incorporate into the one-to-one sessions the central take-home messages from the group session.
Finally, facilitators were briefed on monitoring and evaluation procedures, including tracking attendance, scheduling participants for sessions, and following up with participants who miss sessions. They were also given a refresher session on using the PowerPoint presentation materials on laptops. The assistants attended a 1-day training workshop run by ND that covered basic video camera skills, activities to do with the children, and roles and responsibilities during sessions – such as preparing refreshments, filming, watching over the children.
Regular supervision is provided throughout the intervention. The trial manager (ND) meets with the facilitators for 2 to 3 hours at the end of each week and reviews how the sessions that week went. During the first half of the meeting the two facilitators discuss aspects that went well, challenges, and logistical issues. They also identify particular participants who are experiencing difficulties in applying the programme with their child, and discuss the support these individuals may need in their next one-to-one session. The second half of the meeting involves preparation for the following week’s session. The group go through the PowerPoint slides, discuss specific examples or strategies to use, and make sure that the facilitators have no unanswered questions or queries about the forthcoming session. Finally, the group reviews the attendance records from the past week, and discusses plans for catch-up sessions for any participant who may have missed the session. Every intervention session is video-recorded, and one session each week per facilitator is checked by ND for delivery fidelity.
Data collection
Data collector training
A team of three data collectors have been trained in the child assessments and caregiver interview questionnaires. Training was held over a 3-week period and followed a data collector manual developed by ND, LM and PC. All three data collectors had previous experience administering questionnaires and child assessments, including administration of some of the measures used in the present study. During the three assessment waves, ND makes regular checks, both in vivo and though examination of the videos made, to ensure fidelity of assessment administration. All data collectors were familiar with consent and referral procedures, as well as how to discuss potentially sensitive topics during interviews with caregivers.
Procedures
All 140 carer/child pairs are assessed on three occasions: at baseline, following the 8-week intervention, and 6 months post intervention. For the baseline assessment, caregivers are contacted by the data collection team, and the study is explained to them, including that participation is entirely voluntary. A suitable time for them to come in for assessments is arranged. A driver picks participants up from their home and brings them into the research centre located in central Khayelitsha. On arrival, participants are offered refreshments for themselves and their child. Consent is then explained again and caregivers provide consent for both themselves and their children. Assessments last for up to 2.5 hours. This comprises specific assessments of the child (e.g. Early Childhood Vigilance Task), interviewing the caregiver (e.g. Communication Development Inventory), and filming the caregiver and child in interactive tasks (e.g. book-sharing). There are frequent breaks for drinks and snacks and, if the child shows any signs of tiredness or distress, the session is interrupted or, if necessary, terminated. At the end of the assessment session participants are given a food voucher (rand equivalent of US$8) for a local grocery store to compensate them for their time. Similar procedures are followed for the subsequent two assessment waves. To minimise assessment bias, assessments of children and caregivers are being carried out by data collectors who are blind to group allocation. All coders of video data will also be blind to allocation. Participants are requested not to reveal their allocation to data collectors.
Retention
Provisions have been put in place to maximise participant retention. This includes phone calls to remind participants of scheduled assessments. Where necessary, members of the data collection team visit the participant’s house to discuss arrangements for assessments, making every effort to accommodate the caregiver – including holding assessments on Saturdays for caregivers who work during the week.
Primary outcome measures
Child language
Child language is assessed by interviewing the primary caregiver with the short form of the MacArthur Bates Communication Development Inventory (CDI) [
50]. This 100-item checklist, which has previously been used in other African contexts [
51], provides information on child expressive and receptive language. Aggregate scores are calculated and used as interval scale variables. This assessment is made at all three assessment points.
An adapted version of the Peabody Picture Vocabulary Test (PPVT) [
52] is used to assess child language comprehension directly, at baseline and post intervention. This consists of 24 items displayed on a screen in groups of four. The child is asked to point or ‘touch’ certain items by the assessor (‘Where is the dog. Show me the dog. Point to the dog’).
For expressive language, a 15-item adapted version of the Expressive One Word Picture Vocabulary Test (EOWPVT) [
53] is administered at baseline and post intervention. The child is prompted to say the names of images that are displayed on a screen (‘Look at the picture [child’s name]. What is that? What is that called? Can you tell me what that is?’). Furthermore, the Bayley Scale of Infant Development [
54] language subscales will be used. These provide a comprehensive measure of expressive and receptive language abilities and have previously been used in a study in peri-urban Kenya [
55].
Both the CDI and the adaptation of the Peabody were used in our previous study evaluating book-sharing, and were found to be sensitive to the intervention and to be related to parenting [
45,
46,
49].
Child attention
Child attention is measured using the Early Childhood Vigilance Task (ECVT) [
56]. This is a screen-based assessment of sustained focal attention during which the child views interesting moving cartoon stimuli. The child monitors the screen as images appear, disappear, and then reappear over a period of 7 min. Infant sustained attention is indexed by the number of seconds the child attends to the screen, expressed as a proportion of the 7 min of the video. This assessment is made at all three assessment points. The ECVT has been used successfully in other African contexts [
57], as well as in our previous RCT [
45,
46].
Child prosocial behaviour
This is assessed directly in a prosocial ‘helping’ task where a scenario is created that gives the child the opportunity to help the assessor locate her lost pen [
46,
58]. ‘Helping behaviour’ is scored if the child picks up the lost pen and returns it to the assessor, or points to the lost pen, or verbally indicates its location to the assessor. This assessment, based on a task reported by Buttelmann and colleagues [
58], was used in our previous trial of book-sharing and was found to show effects of the intervention [
46].
In addition, the child’s main caretaker is interviewed using the prosocial scale of the Strengths and Difficulties Questionnaire (SDQ) [
59], a measure that has previously been used successfully in South Africa [
60]. This is a five-item subscale, that uses a 3-point Likert scale that can be aggregated and used as an interval scale variable of raw scores. This assessment is made at all three assessment points.
Child aggression
The child’s main caregiver is interviewed using the aggression subscale of the Child Behavior Checklist (CBCL) for ages 18 months to 5 years [
61]. This is a 20-item questionnaire that uses a 3-point Likert scale on which children are rated according to various types of aggressive and defiant behaviour. An aggregate of raw scores is used as an interval scale variable that can be dichotomised. This measure has been used successfully in several South African studies [
62‐
64].
Direct measures of child aggression and defiance/noncompliance are obtained from coded video data of two parent-child interaction tasks: a ‘Don’t touch’ prohibition task, and a ‘Clean up’ compliance task [
65‐
67], and one frustration task – the ‘Barrier’ task. The first two tasks have been used to assess child defiance in several HICs [
66,
67]. Since they have, to our knowledge, not been used in LMIC contexts, baseline videos will be examined and culturally sensitive modifications will be made to existing coding schemes. The Barrier task has also been widely used in HICs [
68], as well as in our previous work in South Africa [
69], to provide a measure of negative reactivity (on the basis of latency (3-point scale) and intensity (5-point scale) of negative emotion), and constructive versus nonconstructive emotion regulation strategy.
Data management
Data are collected on tablets and, once complete, automatically submitted to a secure server platform hosted by Mobenzi, a South African organisation that specialises in software development for research purposes. Participants are allocated personal identification numbers that are used in all study records to protect their identity and maintain confidentiality. All child assessments and caregiver-child interaction tasks are video-recorded, for both coding and quality control purposes. Videos are labelled by ND and saved in a separate location at the end of each day. In addition, a random subsample (10%) of videos is checked by ND for fidelity to the assessment procedure. Data transmitted from the tablets are stored on a secure central network server.
Data analysis
Data analysis will be completed by a designated statistician/statistical team independent from study investigators. Group baseline differences will be assessed using independent t tests and Mann-Whitney U nonparametric tests if data do not fit necessary assumptions. Analysis of baseline group differences will also include sociodemographic data such as gender and household factors (e.g. income, employment). Analysis of covariance will be used to assess intervention effects at post intervention and follow-up. Post-test and follow-up scores for primary and secondary outcomes will constitute dependent variables, while child age, sex and baseline scores will be controlled for as covariates. Intention-to-treat analysis will be used to examine intervention effects. Missing individual-level outcome data will be addressed using multiple imputation methods.
Mediator analysis will aim to identify certain active components of the intervention and elucidate the pathways to change. To this end, the following two questions will be examined: whether improvements in maternal sensitivity and reciprocity in the book-sharing context mediate improvements in child language and attention; and whether increases in maternal sensitivity and mental state talk in both book-sharing and non-book-sharing contexts, and reduction in negative parenting and increase in supportive parenting, mediate improvements in child social understanding, prosocial behaviour, and aggression.
Moderator analysis
An exploratory subgroup analysis will be conducted to investigate whether certain groups benefit more or less from the intervention. Subgroup analysis will be explored for carer relationship (mother, father, grandparents), child sex, number of sessions attended, family socioeconomic adversity, parental stress, and caregiver mental health. Potential mediators and moderators of the intervention will be explored using mixed linear models.