RCT of a NHV program delivered from pregnancy to children’s second birthdays, embedded in and compared with Australia’s existing universal Child and Family Health Nursing services (usual care). Published protocol https://doi.org/10.1136/bmjopen-2016-013307 [14]. This paper presents analysis of linked administrative data obtained in 2019-22, reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement.

Researchers recruited pregnant women attending antenatal clinics of 10 public maternity hospitals across Tasmania and Victoria, 30 April 2013 to 29 August 2014. Both states are multicultural and seek to provide healthcare and health promotion with culturally and linguistically diverse families including Aboriginal and Torres Strait Islander communities [23, 24]. Trial enrolment was offered to all eligible and consenting women. The trial did not recruit participants according to cultural background nor was able to modify the provision of the program at this stage. Eligible women: (i) had due dates before 1 October 2014, (ii) were less than 37 weeks gestation, (iii) had sufficient English for face-to-face interviews, (iv) lived within travel boundaries specified by participating areas; and (v) had 2 or more of 10 risk factors identified at screening (young woman during pregnancy; not living with another adult; no support in pregnancy; poor health; a long-term illness, health problem, or disability that limits daily activities; currently smokes; stress, anxiety or difficulty coping; low education; no person in the household currently earning an income; and never having had a job before). Women were excluded if they: (i) were enrolled in an existing Tasmanian NHV program for 15-19-year-olds, (ii) did not comprehend the recruitment invitation (e.g., intellectual disability), (iii) had no mechanism for contact, or (iv) experienced a critical event (e.g., termination of pregnancy, stillbirth, child death).

Following screening, eligible women provided informed consent and completed a home-based baseline interview. Women were randomized to control or intervention groups with a 1:1 allocation following a computer-generated schedule stratified by site and parity (first-time parent). Managerial staff, participants and intervention teams were aware of allocation. Researchers who conducted annual follow-ups were blinded to randomization. At the 1-year interview, the 637/722 (88.2%) participating parents were invited to consent to future data linkage with their child’s school transition data. Figure 1 shows that when the linked data were requested from the state education departments, n = 198/237 (83.5%) Tasmanian and n = 420/485 (86.6%) Victorian children had consent for linkage and women had not withdrawn from the original cohort of n = 722.

Conducted in partnership with the Tasmanian and Victorian state governments, the right@home NHV program was developed from reviews of the evidence for factors that promote children’s neurodevelopment, effective interventions for home-based parenting programs, and processes for working with families experiencing adversity [4]. The resulting intervention was structured using the Maternal Early Childhood Sustained Home-visiting (MECSH) framework and training [25], augmented by five evidence-based strategies for content (infant/child sleep, safety, nutrition, regulation, bonding/relationship) and two delivery approaches (video feedback and motivational interviewing) [4, 14]. When the intervention ended, nurses supported families to connect with the local community-based services. Implementation was enabled using detailed fidelity monitoring [26]. An Expert Reference Group incorporated stakeholders and experts to advise on the design, implementation, and interpretation of the trial; no formal data monitoring committee was implemented. The trial is registered at ISRCTN89962120 (status: complete). Funding was obtained to extend direct follow-up (annual interviews and assessments) until child age 6 years and are previously published [12, 15–17].

Women randomized to the intervention group were offered 25 nurse home visits (mean 23.2 home visits [SD 7.4] received), commencing antenatally and delivered mostly by the same nurse (of 18) trained in the right@home NHV model [17, 26]. Nurses were Child and Family Health Nurses who, during the period of implementation, required nursing and midwifery qualifications. Most intervention women (75.6%) also received one or more home visits by a social care practitioner (mean 1.7, range 0-15), who provided case management as needed (e.g. connecting families to services such as emergency relief and legal aid) [17, 26].

Women in the control group received up to six (Tasmania) or nine (Victoria) free consultations to age 2 years (mean 7.6 consultations [SD 4.3] received) [17]. After an initial home visit, subsequent appointments were conducted in local clinics. The Victorian service also included flexibility to offer additional home-based appointments in the first year postpartum depending on family need.

The items and scoring for the Tasmanian Kindergarten Development Check (KDC) [27] and Victorian School Entrant Health Questionnaire (SEHQ) [28] are described in Supplementary Table 1. The KDC was developed for the Tasmanian Government in 1994 to identify Kindergarten students who were not achieving expected development outcomes. Subsequent revisions over time were made in line with the state government’s curriculum framework, although the item sources were not specified. The version completed by educators for children in the current study comprised 21 items across five sub-domains [27]. The publicly available KDC information states: “The Check provides information to support teachers’ educational planning and referral to allied health professionals when required” [29].

The Victorian SEHQ has been distributed since 1997, and also undergone revisions over time. The publicly available information states: “The SEHQ is an annual survey that records parents’ concerns and observations about their child’s health and wellbeing during their child’s first year at school. The questionnaire is completed by parents and guardians of Prep children in Victorian primary schools through the Victorian Primary School Nursing Program across the year. The information collected in the SEHQ is a starting point for nurses to carry out further assessment of the child and family and determine appropriate intervention and/or referral as required. Analysis of the SEHQ data is also used to inform planning and service delivery” [22]. In the version completed by caregivers of children in this study, the Strengths and Difficulties Questionnaire (SDQ) and the Parental Evaluation of Development Status (PEDS) were included as measures children’s behavior, emotional wellbeing, health and development (Supplementary Table 1). Children’s speech and language, health service use, and family issues and stressors, were assessed with a range of categorical items that were originally selected through literature reviews, piloting and revision, although the sources were not specified [28].

The procedures for obtaining linked data were similar between jurisdictions. They involved completing online applications to the state education departments for access to the data, which, once approved, were followed by securely sharing copies of the participant consent forms and a summary of identifying data (name, date of birth, school if known). The education departments then identified and provided the participating student data. Consistent with the literature on using population data linkage for research, the methods for data capture, processing and linkage were opaque [20]. In correspondence with the departments, the lead author learned that this was likely because many individuals and departments are responsible for the many steps (e.g. survey distribution, collection, scoring, data entry, cleaning, linkage) and information is not always available or shared between them.

The Tasmanian children in right@home turned four years old and began kindergarten in 2018-20. The Victorian children in right@home turned five years old and began school in 2019-21. Both departments publish annual reports summarizing the measures [22, 29]. The published data (termed “state-wide” throughout) are presented from 2020 for comparison as this was the closest year with data available. The Tasmanian KDC was intended for completion by educators of the 70% of students enrolled in a government kindergarten program; however, neither the denominators nor numerators are published. The Victorian SEHQ was completed by n = 53,967 (66%) of eligible enrolments in 2020, which was a lower response fraction than earlier years (around 80%) due to the COVID-19 pandemic. Demographics and outcomes of responding parents were similar across the years. Neither state’s descriptive data were weighted to approximate population characteristics and data on representativeness were not published.

Given the complex nature of the right@home NHV intervention, multifactorial outcomes are required to evaluate the program across the breadth of intended effects [30]. To comprehensively evaluate the balance of evidence for treatment effects, we examined the direction and magnitude of estimated effects, including uncertainty and variability, for the multiple health and development and health service outcomes [31]. This approach follows the rationale for our previous stages of the trial evaluation [12, 15–17]. The KDC and SEHQ cannot be harmonized so they were analyzed and reported separately.

Figure 1 presents the participant flow (CONSORT). Of the 722 women enrolled in the right@home trial, data were successfully linked (matched) for n = 134/237 (56.5%) Tasmanian and n = 252/485 (52.0%) Victorian children. Data linkage was not possible if the KDC/SEHQ assessment was not completed, the child was no longer enrolled in an eligible primary school, or the child’s name or date of birth did not match study information; however, reasons were not enumerated by the education departments. The proportion of women who consented and had matched data was higher for the intervention (n = 212/363, 58.4%) than the usual care group (n = 174/359, 48.5%). This is likely due to having more contact with the intervention women in the first two years of the trial.

Table 1 presents the enrolment (baseline) characteristics for each trial group, by participating families with linked data and lost to follow-up. More families with either parent born in a non-English-speaking country, or with no more than high school education, were lost to follow-up. At randomization, the usual care group had slightly higher proportions of female babies and 3 or more risk factors at screening, and these differences were evident in the follow-up frequencies. Otherwise, the distributions of participant characteristics by follow-up status and trial group were similar.

Table 2 shows that the usual care cohort (Victorian SEHQ) experienced at least 2.5 times the proportions of parent divorce/separation, serious illness of parent, and parent change of job than the state population, and 3–4 times the proportions of historical adversities including parent substance use or mental illness, parent or child abuse, and other family violence.

Table 3 shows that children in the right@home usual care cohort (Tasmanian KDC) were half as likely to have achieved 20 of the 21 KDC items in kindergarten and one-third as likely to have achieved all 21. Table 4 shows that the right@home usual care cohort (Victorian SEHQ) were approximately 1.5 times more likely to have difficulty putting words together, a voice that sounded unusual, or a stutter or stammer, compared with the state-wide proportions, but otherwise had similar proportions for being unclear or any speech or language difficulties. Except for the SDQ prosocial subscale, the proportions of moderate or high problems for the right@home cohort (Victorian SEHQ) were higher for the SDQ scores, notably for the emotional, hyperactivity and prosocial subscales, which were two-to-three times those of the state.

Table 5 shows that, compared with the state, more children in the right@home usual care cohort (Victorian SEHQ) were diagnosed with asthma, and visited maternal and child health nurses, an optometrist, speech pathologist or early learning center. Proportions for allergy diagnoses and other health service use were similar.

Table 3 and Figure 2 present the KDC outcomes for Tasmanian children. The estimated ORs for the five sub-domains indicated that more children in the intervention group had achieved the development milestones than children in the usual care group. The estimated group differences for achieving 20 or 21 of the 21 indicators (OR = 2.32, 95% CI: 1.11 to 4.87; and OR = 2.48, 95% CI: 0.97 to 6.34, respectively) were slightly more precise than most of the sub-domains.

Table 4 and Figure 3 present the SEHQ health and development outcomes collected for Victorian children. When considering the ORs and confidence intervals by SEHQ domains collectively, there were no clear group effects. Intervention parents appeared more likely than usual care parents to report that their child was unclear to others (OR = 2.18, 95% CI: 1.39 to 3.45), and therefore that their child had any speech or language difficulty (OR = 1.71, 95% CI: 1.15 to 2.55). However, intervention parents were less likely to report concerns about their child’s learning, development or behavior (OR = 0.61, 95% CI: 0.47 to 0.80).

Table 5 and Figure 4 present the health service use outcomes for Victorian children. By school transition, more children in the intervention group had accessed health services than children in the control group. The largest group differences were for obtaining an allergy diagnosis (OR = 2.00, 95% CI: 1.08 to 3.72), seeing a maternal and child health nurse for the scheduled 3.5-year-old check (OR = 1.41, 95% CI: 0.99 to 2.02), a dentist (OR = 1.69, 95% CI: 1.24 to 2.30), and a speech pathologist (OR = 1.75, 95% CI: 1.1 to 2.79).

Supplementary Table 2 shows that using available case data led to an underestimation of the prevalence of family issues and stressors (Table 2), which is not surprising given that nonresponse is higher in experiencing higher adversity. There were only modest differences in the results between the primary analyses above and the available case analyses (Supplementary Tables 3–5), suggesting that the analyses of group differences were not highly sensitive to the assumptions made about the missing data.