Trial of Healthy Relationship Initiatives for the Very Early-years (THRIVE): a Three-Arm Randomised Controlled Trial for Mothers Identified as Vulnerable in Pregnancy and their Babies who are at High Risk of Maltreatment

Design: A three-arm randomised controlled trial. Women vulnerable in pregnancy as identified by NHS GGC’s SNiPS [3] will be randomly allocated to: 1) ETPB 2) MB or 3) TAU. Settings: The interventions will take place in community based venues. Target population: Vulnerable pregnant women as identified for the trial by NHS GGC’s SNiPS [3] Two interventions are being evaluated: ETPB and MB. They have important similarities and differences. Both aim to reduce maltreatment and improve developmental outcomes for children; work with women from 20 weeks of pregnancy; are run in groups of ~8 participants; are delivered by two trained staff (5 days training); include information on babies’ development; and incorporate cognitive behavioural therapy to help mothers’ mental health. However, they have differences in focus that may influence how effective they are at reducing child maltreatment. They have different theoretical foundations, perinatal phase, level of involving fathers and content. ETPB is informed by social learning theory. It consists of 4 antenatal group sessions and 4 postnatal telephone consultations with a further 4 individual, 1-hour sessions (Enhanced) in order to ameliorate ongoing maternal psychological distress in this group. ETPB sessions take from 30 minutes (telephone) to 2 hours (group) and the intervention averages around 14 hours in total. Its emphasis is on families and includes fathers, with very practical content around expectations and skills to meet the new challenges whilst ideally maintaining a happy family or at least reducing family discord. MB is underpinned by attachment theory and designed to target mothers who are vulnerable in pregnancy according to the Special Needs in Pregnancy Services protocol (SNiPS).[3] It involves 7 antenatal group sessions (each 2 hours, i.e. 14 hours in total), focuses on mothers, although fathers are invited to one session; and the content focuses on encouraging nurturing, engagement and synchrony. MB has shown uncontrolled effect sizes for anxiety and outwardly directed irritability of 0.7 and 1.2 in before and after analysis.[4, 5] Measurement of outcomes and duration of follow-up: Baseline data will be collected by health visitors or mid-wives (HVs) after week 12 of pregnancy in the mothers’ homes. First follow-up will be when the baby is 6 months and second follow-up when the baby is 18 months old (same data collection procedures). We have powered on two principal outcomes, when the baby is 6 months and both are proxies of maltreatment. The mother-centred outcome is the HADS, enhanced by irritability questions from the AWS.[6, 7] The child-centred component is the Care Index (overall maternal sensitivity and infant cooperativness score) which represents the mother-child interaction quality.[8] Language development will be a secondary outcome when babies are 18 months.[9] We aim to link to routinely collected data to track children on the at risk register, taken into care and attending accident and emergency. The sample is being followed for a further year to establish whether effects are maintained and to be able to measure impact on language development, because poor language is a strong indicator of maltreatment.[9] However, the principal outcomes are at first follow-up to protect against possible contamination between arms of the trial in the baby’s 6-18 months due to the potential use of a wide range of services. Process evaluation: will investigate the fidelity of programme delivery, practitioners’ characteristics and perceptions, mothers’ engagement, the importance of different intervention components, and contextual factors facilitating or inhibiting delivery and participation. All practitioners will complete post-session protocol adherence checklists and a practitioner questionnaire, and ~8 key practitioners will be interviewed in depth. All mothers will be asked to complete a brief programme evaluation questionnaire at home. Ten mothers in each arm will be interviewed in-depth, and we envisage a further 20-30 will be interviewed to address specific issues as they arise. A health economics evaluation will assess the costs associated with the delivery of each intervention and TAU from the NHS and Personal Social Services perspective favoured by NICE. Costs to participants and families will be examined as part of a sensitivity analysis. The cost-effectiveness will be assessed by comparing the additional costs associated with each of the interventions to the outcomes achieved in the study and those achievable in the longer term. These longer term outcomes will be assessed by linking the short term outcomes identified in the study to longer term impacts on health and wellbeing for both mother and child via relationships identified from the literature. Sample Size: We will analyse two primary outcomes, each at a significance level of 2.5%. For each outcome, two analyses will be performed in a hierarchical fashion, so no further p-value adjustment needs to be made. We shall first test whether the two active intervention groups combined differ from TAU, and if significant we shall compare the two active interventions. To have 90% power to detect an effect size of 0.4 between the two active interventions will require 157 participants in each group. Comparing these 314 subjects with TAU, 90% power to detect an effect size of less than 0.5 can be achieved with only 63 participants in the TAU group (i.e. for every 12 participants randomised, 2 receive TAU, and 5 receive each active intervention). Therefore, 377 participants are required. To allow for 25% loss to follow up at 6 months, 500 participants will need to be randomised (NHS GGC have confirmed that that 500 is a small proportion of their vulnerable mothers). Under these assumptions, the study has 80% power to detect an effect size of 0.43 between the active intervention groups and TAU, and an effect size of 0.35 between the two active interventions. Planned Analysis: Baseline-adjusted linear regression analysis (ANCOVA) will be used to compare primary outcomes between intervention groups. Similar methods will be used for other outcomes (using data transformation and alternative regression methods, depending on the distribution of each outcome). Regression models will be extended to investigate the effects of baseline characteristics. Repeated measures methods will be applied to outcomes collected at more than one post-baseline assessment. Missing data will not be imputed in the first instance, but the sensitivity of key results will be assessed under alternative assumptions regarding missing values. Project timetables including recruitment rate: The project will last 5 years. In the first 2 years we expect to recruit 500 women and interventions will run concurrently with recruitment until 2 years and 2 months into the project. The final Wave (3) of data collection will be complete by Sept 2016, allowing for the completion of data processing, data entry, analysis and writing-up in the final 6 months.