Design
We have used the SPIRIT checklist for producing this protocol and made amendments based on the CONSORT ROUTINE guidelines for cohort RCTs, and the guide to reporting protocols for pilot and feasibility studies (28–30).
This study aims to assess the feasibility of a TwiCS evaluation of the IY-T programme using BiBBS cohort participants. The TwiCS will have two arms with a 1:1 random allocation ratio (intervention:control). Although this deviates from the ‘random selection’ method proposed by Relton et al. (2010), this approach is still in line with TwiCS methodology, as randomisation is occurring from a cohort of participants, and consent is staged (31).
Cohort
The cohort is the Born in Bradford’s Better Start (BiBBS) birth cohort which recruits pregnant women and their newborn babies from the three inner city Better Start Bradford areas. Better Start Bradford is an initiative which provide a range of interventions for expectant families and families with children aged 0–3 in Bowling and Barkerend, Bradford Moor and Little Horton (three areas within Bradford). Most of the Better Start Bradford area falls into the most deprived 10% of areas in England (Bradford Council, 2019; GOV.UK, 2019). Bradford district is the 13th most deprived local authority of 326 in England (City of Bradford Council, 2019, 2021).
Pregnant mothers are eligible for recruitment to BiBBS if they are living in the Better Start Bradford area and are registered to give birth at Bradford Teaching Hospital NHS Foundation Trust (BTHFT) (16). Upon recruitment, women complete an in-depth baseline questionnaire during pregnancy, and consent to routine linkage to both their own and their child’s health and education records, and records of their participation in Better Start Bradford interventions. BiBBS recruits 54% of the eligible population and is representative of the eligible pregnant population, therefore the intervention and control participants in this study are also representative of this area (17). All BiBBS women that are eligible to receive the IY-T programme, and have not yet received it, will be identified and form the eligible population.
Consent
When recruited into the BiBBS cohort, participants are asked to sign a consent form, which includes permission for researchers to access their routine data and to be randomly selected to receive an intervention or to act as a control to evaluate that intervention, in line with guidance on TwiCS designs (9). The consent statement was developed with the Community Research Advisory Group to ensure clarity and understanding with participants and states: “I understand that if there are not enough places for everyone to take part in Better Start Bradford projects, families may be selected to take part by chance (randomly). If my family are not selected to take part in a project, information on me and my child may be compared with families who have been selected to take part” (see Consent form for Pregnant Women v4 21.02.18).
In line with TwiCs design, additional consent is not required for the random selection of participants from the BiBBS cohort for this study (see Fig. 1) (9). BiBBS participants are informed that they have the right to decline consent without having to provide a reason, and are able to withdraw from the study at any time. This study will follow the BiBBS processes of study withdrawal (16). Any participants who withdraw from BiBBS prior to the TwiCS processes will not be included in this study. If participants withdraw consent after they have been randomised into the IY-T TwiCS, their outcome data will be included in the final study analysis unless they specifically request that this data not be used.
Research ethics approval
The protocol for BiBBS recruitment and collection of routine outcome data was approved by Bradford Leeds NHS Research Ethics Committee (15/YH/0455). Research governance approval was gained from Bradford Teaching Hospitals NHS Foundation Trust. The existing ethics includes approval for the evaluation of Better Start Bradford, including the use of cohort participants to create control groups. It also states that full details of any TwICS or RCTs will be submitted as sub-study amendments to the existing protocol. The protocol for the current sub-study has been approved by the Bradford Leeds NHS Research Ethics Committee as an amendment to the existing BiBBS protocol.
Intervention
Better Start Bradford commissioned Barnardo’s (a large UK based children’s charity) to provide and deliver Incredible Years Toddler (IY-T) in the study site (https://www.barnardos.org.uk/). IY-T covers 8 key topics such as 'social and emotional coaching' and 'the art of praise' which are delivered through two-hour sessions over 13 weeks by two trained group facilitators who promote peer support and shared learning. The programme ultimately aims to promote parent-child interactions and positive parenting strategies for participating parents. This is thought to promote improved social and emotional development, and support children to enter school with improved language and communication skills. Prior to the programme starting, parents receive 3 promotional contacts, consisting of telephone contact and at least 1 home visit. The initial telephone contact will introduce the parents to the project and facilitators and build their confidence in attending. The home visit builds rapport between the family and facilitators, and involves the completion of pre-course questionnaires, and identification of any barriers that families might have in accessing the group such as crèche, language difficulties or concerns about what the group might involve. For more detail on the theory of change, content and delivery of the Incredible Years Toddler intervention, please see the programme manuals (https://incredibleyears.com/books/incredible-toddlers/).
Group facilitators attend an initial 3-day training in the programme, and guidance from the programme developed recommends that facilitators should also engage in regular supervision and pursue official accreditation. The accreditation process is rigorous, requiring group facilitators to provide evidence of delivery including video footage of sessions and various forms and checklists. The delivery agents currently have six facilitators in total, two of which are accredited, and two of which are currently in the accreditation process. The programme is delivered in a combination of face-to-face and virtual formats (dependent on lockdown rules in place at the time of the study and participant needs). Barnardo’s have delivered IY-T with high levels of intervention fidelity and have engaged in regular supervision and successfully achieved accreditation for two of their group facilitators. We have been conducting monitoring and evaluation of the programme for several years (reports available at https://borninbradford.nhs.uk/what-we-do/improving-health/bsb-innovation-hub/).
Trial participants
For this feasibility TwiCs of IY-T, caregivers are eligible if they:
provided consent to the BiBBS cohort study and agreed to be contacted for future research
Have not withdrawn consent to the BiBBS cohort at the time of randomisation
Are still living in the Better Start Bradford area at the time of randomisation
have one or more BIBBS child(ren) aged between 12 and 36 months at the time of randomisation
NHS tracing confirms that their child is still living with them, and is alive
have not already received IY-T in the Better Start Bradford area for any of their children[1]
Implementation
Figure 1. Flow chart describing the implementation of the feasibility TwiCS procedures
Figure 1 presents how study participants will be drawn and randomised from the BiBBS cohort. A Standard Operating Procedure (SOP) was developed for this study. Participants randomised to intervention will initially be contacted by a designated researcher from the BiBBS team, who will confirm their eligibility and ask if they consent to their details being passed onto the IY-T team at Barnardo’s. Those who cannot be contacted after four attempted contacts will be recorded as ‘unable to contact’ (Box A). For each individual woman who is contacted, verbal consent will be sought for her details to be shared with the Incredible Years team. Those who are contacted, but who decline consent will not be followed up and will be recorded as having been offered the intervention but declined (Box B).
For those who agree to the referral, the BiBBS team will pass on the referral to the IY-T team who will then re-contact them by telephone. If participants are not able to be contacted at this stage, they are recorded as such (Box C). If IY-T assess the referral as ineligible, they are recorded as such (Box D); this should be unlikely, however, circumstances may change e.g. a child becomes ‘too old’ or a child is removed from the parents. We will therefore record any occurrences of this, with reasons where possible. If they can be contacted, this phone call will allow the IY-T team to provide them with more detail about the specific programme available to them and check the eligibility of these participants. If the participant accepts the offer a home visit with one of the IY facilitators will be arranged. More information about the programme will also be sent out to all women who accept the offer of a home visit. If parents initially accept the offer from BiBBS, but not from IY-T, they will be recorded as having been offered the intervention but declined (Box E).
The numbers randomised (n = 240) and offered IY-T (n = 120) in this feasibility study aims to fill two IY-T courses (n = 24). If the number of study participants is not sufficient to support optimal group sizes (12 per group) the IY-T team may ‘top up’ groups by including parents referred to them from other services. These parents are not study participants and will not be included in the research.
Randomisation
Eligible participants in the BiBBS cohort will be individually randomised 1:1 to the intervention (n = 120) or control group (n = 120), using blocked randomisation with stratification by child age (1 year or 2 years at the time of randomisation) and ethnicity (White British, South Asian, or other). The six allocation sequences (one for each stratum) will be generated using Stata/SE v17.0 (for Windows 64-bit x86-64) or later, using the user written Stata command ralloc (Ryan, 1997).
We will draw a stratified random sample of 240 participants from all eligible participants in the BiBBS database, with sampling fractions (approximately) proportional to the distribution of the six randomisation strata in the eligible cohort population. The \({n}_{i}\) sampled participants in stratum \(i\), will then be randomly sorted and matched against the first \({n}_{i}\) allocations in the allocation sequence for stratum \(i\).
Statistical methods
The feasibility study will apply the CONSORT-ROUTINE reporting guidelines and the flow diagram where relevant. As this is a feasibility study, reporting guidelines about the intervention outcome are not relevant and will not be described for this study.
The feasibility outcomes are described in Table 2 below. These will be reported descriptively using raw numbers and percentages, with 95% Wilson binomial confidence intervals to provide some indication of the uncertainty associated with the observed point estimates.
Table 1
Projected target figures
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Rationale for target figures
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120 randomised to intervention → 84 women are contactable]
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80% of women were contactable for the BiBBS postnatal sweep, which takes place approximately 12 weeks after recruitment into BiBBS. We will contact women 1–3 years after recruitment into BiBBS, and so we have set our rate to be lower at 70%.
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84 women contacted → 44 women consent to the referral → 22 women enrol
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On average, the rate of conversion from referral to enrolee in IY-T is 52%. We therefore anticipate that 52% of randomised BiBBs participants will agree to be referred, and 50% of those referred will enrol into the programme.
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22 enrolees → 20 enrolees go on to participate
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On average, 89% of enrolees to IY-T are converted into participants. We have set a target of 90% of randomised enrolees to be converted into participants.
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20 participants → 12 participants go on to complete
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60% of participants go on to complete IY-T. We have set our rate to be 60%.
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We will also report a description of the selected intervention and control participants with regards to their sociodemographic characteristics and compare feasibility outcomes across sociodemographic groups where possible. We will suppress any counts of < 5 to protect participants identity. All counts of missing data will be reported where known, with reasons where possible.
Sample size
The IY-T service delivery team have the capacity to deliver two groups for this feasibility TwiCS. Each IY-T group aims to recruit 12 parent-child dyads (hereafter referred to as enrolees) and retain 10 participants. We have therefore based our sample size to be randomised (n = 240) on achieving these numbers (24 enrolees total, or 12 enrolees per group) (see below for details on how these numbers have been derived).
Feasibility outcomes
We have based the feasibility outcome targets on data from two key sources. The first relates to a postnatal data collection sweep conducted as part of the main BiBBS cohort study. The second is information on rates of IY-T enrolment, participation and completion (where an ‘enrolee’ is referred and seen face to face in at least one pre-course contact, a ‘participant’ is someone who attends at least one week of the groups, and a ‘completer’ is someone that attends at least 8 of the 13 group- based sessions) reported by Barnardo’s and the Better Start Bradford Innovation Hub (see https://borninbradford.nhs.uk/what-we-do/improving-health/bsb-innovation-hub/).
Table 1 summarises our target figures and how these were decided upon, and Table 2 (below) summarises these targets and outlines how feasibility objectives will be assessed. In addition to the above, we also aim to assess contamination (any overlap between allocated control group, and non-randomised intervention group participants), and aim for this to occur in < 1% of the sample. A RAG rating system has been applied to support the feasibility assessment of each objective: to be rated as green (achieved), amber (partly achieved) and red (not achieved). For an objective to be achieved and rated green, it must reach the percentage level specified above (e.g. 70% for contactable women, 50% for converting randomised participants into referrals). The levels at which we reach amber are equal to the green target, minus 20%. This is except for the rate for contamination (objective 1.2), where the rates are set on achieving less than 1% contamination.
Table 2. Feasibility objectives and outcomes
Trial management
The trial is considered low risk and oversight will be provided by the Incredible Years working group and the programme management group of the Innovation Hub. The study research team will be responsible for the allocation of participants to interventions, routine data linkage, and all data analysis. All other elements of the study will be performed by individuals external to the research team as detailed below.
Recruitment into the BiBBS cohort is currently undertaken by a team of multilingual Community Research Assistants. The BiBBS community research assistants will offer the referral to IY-T for BiBBS participants. This team have Standard Operating Procedures (SOPs) for contacting and enrolling parents into the intervention. Enrolment of participants onto the IY-T programme will be the responsibility of the project co-ordinator for the IY-T delivery team based at Barnardos, using their usual recruitment procedures.
Data collection and management
The project level data regarding the number of women who enrol, participate, and complete the programme will be linked to information on BiBBS participants and used in this feasibility TwiCS.
As per the BiBBS protocol, record matches for routine data linkage will be validated on the basis of NHS number plus multiple non-unique identifiers (e.g. surname, date of birth) where possible. The central database, hosted by BTHFT, will store data obtained from Medway and SystmOne routine health and education data. Data from each source will be linked at the BiBBS person level and will be structured and maintained by BiBBS data managers as a long-term strategic store to service cohort data capture and analysis. The entire database schema and data will be backed up nightly. Further details of the routine data management process can be found in the BiBBS protocol.
Monitoring
Harms
There are unlikely to be harms to individuals from taking part in the intervention as it is non-invasive, though is possible that discussions relating to family relationships could highlight potential safeguarding issues for participating parents and/ or their children. To mitigate this risk the practitioners delivering the intervention and community research assistants making the phone calls are trained in safeguarding. The BiBBS study protocol has been approved by the Bradford and Leeds Research Ethics Committee (15/YH/0455). All BiBBS researchers follow Bradford Teaching Hospital Foundation Trust’s Safeguarding Adults and Safeguarding Children policies.
Data monitoring and auditing
This study evaluates an intervention that is already being commissioned by BSB and implemented independently from this study and the evaluation team. The Innovation Hub is conducting regular monitoring of the intervention including reporting on progression criteria that have been agreed with the intervention and Better Start Bradford teams. This information is used by Better Start and the intervention team to inform commissioning and implementation decisions. There are also a number of project management groups for BiBBS conducted within BTHFT described in Additional File 1 in the BiBBS protocol (Dickerson et al., 2016). The sponsor of BiBBS is the BTHFT Research Management and Support Office who may conduct independent auditing of the study.
Dissemination policy
Findings will be produced in reports and shared amongst relevant BSB partners and commissioners in Bradford and England. A briefing will be shared with BiBBS participants through existing communication strategies (including website, social media, newsletters and birthday cards. Summaries of findings may also be widely reported in the local BSB communities using, BiBBS and BSB newsletters, social media and local press. In addition, the findings from this study will be submitted for publication in scientific journals and as conference abstracts.