Effectiveness and cost-effectiveness of a group-based intervention to improve social-emotional development of young children in poverty-stricken areas: A cluster randomized controlled trial

Background Social-emotional ability is key to the well-being and future success of children; however, disparities in social-emotional development during an individual’s early age can last a lifetime, which is particularly evident among children living in poverty-stricken areas. We aimed to determine the effectiveness, cost-effectiveness, and feasibility of a group-based intervention called the Care Group on social-emotional development for families living in poverty-stricken counties. Methods We conducted a cluster (township) randomized controlled trial (C-RCT) every two weeks from July 2019 to June 2020 in a poverty-stricken area located in Shanxi, China. The outbreak of the COVID-19 pandemic suspended the implementation of the intervention in January 2020. The caregiver-child pairs in the intervention group participated in 12 group-based sessions with a structured curriculum and learning materials emphasizing nurturing ability and early childhood development. We applied a difference-in-differences (DID) model to estimate the intervention’s impact. The analysis follows the intention-to-treat (ITT) principle. We used standard economic costing methods to estimate the cost of implementing the Care Group over the intervention period and adopted a societal perspective in the analysis. Results We included 322 eligible caregiver-child pairs in the baseline (intervention n = 136, control n = 186) and surveyed 258 pairs in the endline (intervention n = 117, control n = 141). Compared with the control group, children in the intervention group had significantly fewer social-emotional problems (adjusted mean difference of Z score = -0.374, 95% CI = -0.718, -0.030, P = 0.033) six months after intervention. In the first year, the annual cost of implementing Care Group was US$146.10 per child, reduced to US$47.20 per child in the second year due to the exclusion of non-recurrent costs. The incremental cost-effectiveness ratio (ICER) was US$390.60. Conclusions Care Group is an effective approach for promoting children’s social-emotional development in poverty-stricken areas at an affordable cost and with high feasibility for scale-up. Considering the planned per capita health expenditure of the Chinese government for 2022, we believe that the presented evidence makes a solid scientific and financial case for integrating the Care Group intervention into the basic public health services (BPHS) package. Registration Chinese Clinical Trials Registry (ChiCTR): ChiCTR1900022894.


Online Supplementary Document 2: Compliance of the intervention group
We classified the caregiver-child pairs in the intervention group into four groups according to their participation frequency: Excellent participation (n=10-12 sessions), Good participation (n= 6-9 sessions), Acceptable participation (n=3-5 sessions), Minimum participation (n= 1-2 sessions), No participation (n=0). Caregiver-child pairs with Good to Excellent participation were supposed to have a significant effect in ECD and nurturing care practice compared with control group, while those with acceptable participation and above were supposed to have changes in children's social-emotional development and nurturing care practices.
The percentage of Excellent, Good, Acceptable, Minimum, and No participation in the Care Group intervention was 16.24%, 17.95%, 26.50%, 8.55%, and 30.77%, respectively. The cumulative percentage of Acceptable participation and above was 60.68% (Appendix 4). For the caregiver-child pairs with Acceptable or Minimum participation, the majority (n=29) of them dropped from the intervention during July to August 2019, 1 or 2 months after the initiation of the project. Among them, 26 children migrated to a nearby county due to their elder brother/sister's entering school in September (21 children) or children's parents working in other counties (5 children); the other 3 caregivers refused to tell the reason in the endline survey. Caregiver-child with Good participation reported multiple reasons for absence such as long-distance, difficulty in transportation, and family illness.

Online Supplementary Document 3: Prevalence of social-emotional delay among intervention and control groups
The social-emotional development of children in the intervention group was lower than the control group but without significant difference (p＞0.05). However, the rate of suspected social-emotional delay in the intervention group was much higher than the control group (intervention: 29.1%; control:19.9%), illustrating that the Care Group intervention improved the social-emotional development of children who had severe problems.

Online Supplementary Document 4: The details of the collection of cost items in the groupbased intervention project (in 2019, USD) 4.1 Recruitment costs
Recruitment for our project is divided into two phases. In the first stage, the project team, which mainly included national and county-level experts in maternal and child health care projects, was responsible for recruiting parenting instructors and supervisors. Four supervisors and nine parenting instructors were recruited. The recruitment method is the on-site interview. In the second stage, parenting instructors and supervisors were responsible for recruiting children's parents and children, with 4 supervisors and 9 parenting instructors in charge. The recruitment includes 322 parents of children. Recruitment channels include phone calls, home visits, WeChat, and other new media. In July 2019, the health economics researchers of the project team interviewed a total of 15 staff members on-site, including 9 parenting instructors, 4 supervisors, 1 expert from county-level maternal and child health care center, and 1 national expert. The interview's content includes the interviewees' working situation (whether there is a job, average salary, effective working hours per day), the recruitment way of the interviewees, the recruitment time, and the cost of transportation. All interview data were timely sorted out in Microsoft Excel 2019 (Table S3-1). The recruitment cost is mainly calculated according to the human capital method, which is divided into two parts: the first is the recruitment time cost, which is calculated according to the hourly wage and recruitment time of the recruitment target; the second is the transportation cost caused by recruitment.
The specific calculation formula is as follows: Recruitment cost = unit time (hour) × unit wage (USD) + transportation cost Note: * means no job; # indicates no participation in recruitment According to the calculation of the interview data, the total recruitment cost of this project is USD 558.9, among which the cost of project experts to recruit nurturing instructors and supervisors accounts for the largest proportion, accounting for 63.3% of the total cost.

Details of training costs
From May 31, 2019 to June 14, 2019, the project team organized a two-stage face-to-face training in Fenxi County. The first phase of the training lasted five days. The second phase lasted four days for a total of nine days. 5 experts, 4 supervisors and 9 nurturing instructors participated in the training phase.
The project team supported all the training expenses (including accommodation, transportation, office expenses, and expert labor costs). The health economics researchers of the project team collected the experts, facilitators', and supervisors' time, transportation, accommodation, and office expenses of the whole project through expert interviews and questionnaires. See Table S3-2 for details and costs of training programs. Office fee (USD) 464.0 Training costs mainly include the time cost of experts, supervisors and nurturing instructors, transportation cost, accommodation cost, catering cost and office materials cost. Among them, the time cost is calculated by human capital method. The specific calculation formula is as follows: Training cost = unit time × unit salary (USD) + transportation + accommodation + food and beverage + office expenses According to the research results, the total training cost of this program is USD 11011.7, among which the time cost of expert's accounts for the largest proportion (50%), which is USD 5507.7.

Details of material costs
The material cost is divided into two parts. The first part is the costs of material purchased by UNICEF, which mainly includes record cards, hand puppets, toys, colorful crayons, children's books, and USB flash drives. The second part is the supplementary materials purchased by the Fenxi County project team, mainly the Fenxi County project team, including brushes, building blocks, blackboard writing, solid glue, etc. See Table S3-3 for specific material costs. According to the actual service life of materials, the depreciation method is adopted for materials with a service time of more than one year, such as USB disk, children's books, dolls and so on. According to the research results, the total material cost of this project is USD 2686.0, among which the material cost purchased by UNICEF and Fenxi County project team is USD 2414.9 and USD 271.1 respectively.

Monthly Care Group costs
The intervention frequency of this project was 2 times per month, each activity lasted about 50 minutes, and the intervention was planned for 12 months in total, including July to December 2019, during which monthly intervention activities were normally carried out. From January to June 2020, the activities of the nurturing care group were suspended for the six months due to the COVID-19 outbreak in the country. Parents of children received monthly training from 9 trained parenting instructors, and 4 supervisors conducted monthly supervision, intensive parenting instructor training and home visits. The cost of monthly intervention includes the time cost of preparing and organizing group activities, the time cost of monthly intensive training, the time cost of filling out statements, the time cost of answering WeChat group questions, the time cost of feedback questions, and the time cost of transportation, etc. The health economics researchers of the project team collected the time costs of parenting instructors and supervisors through monthly questionnaires. According to the human capital method, the calculation formula is: Monthly project intervention cost = unit time spent by parenting instructors (hours) × unit salary of parenting instructors (USD) + Unit time spent by supervisors (hours) × unit salary of supervisors (USD) The total time cost for the six months from July 2019 to December 2019 is USD 2834.2. From January to June 2020, due to the suspension of group activities, the time cost for these six months is USD 0. The specific calculation results are shown in Table S3-4. .5 The quality control of economic data In the early and middle stages of project implementation, health economic evaluators have been to the project implementation site to conduct cost collection supervision and verification. Provide training and Q&A for cost collection leaders of each project implementation center at the project implementation site to ensure the accuracy of cost collection in the whole cost collection process. During the implementation of the project, each project supervisor was responsible for the cost accounting form of the intervention center in the region, which was filled out once a month. Then the data was input into the Excel form and sent to the health economics evaluation staff by email. Besides, the original input data proof materials were shipped together in the form of photos.

Online Supplementary Document 5: Changes in family nurturing behavior of intervention and control groups
We utilized the early childhood development questions in the Multiple Indicator Cluster Surveys (MICS-6) to assess nurturing behavior. If any household member aged 15 and above engaged in the activity specified, the question was scored "1". Otherwise, it was scored "0". The total score was the sum of the six questions. Notable changes in storytelling and naming/counting/drawing were seen in the intervention group, and the total scores among the intervention group were significantly higher than that of the control group.