Weight Development in Children With Obesity After Declining Treatment
Condition: Obesity, Child
MeSH terms: Obesity; Pediatric Obesity
Study type: Observational [Patient Registry]

Summary: 
      Childhood obesity is a major health concern and lifestyle intervention is recommended as the
      cornerstone in the weight loss treatment. However, only limited knowledge exists in relation
      to characterization and follow-up of children who decline participation in a lifestyle
      intervention. The aim of this study is to investigate the long-term development in BMI
      z-score for children with obesity who decline to participate in a lifestyle intervention.

      This study identified approximately 170 children with obesity who declined treatment in a
      community-based lifestyle intervention. The development in BMI z-score for these children
      will be compared to children enrolled in the lifestyle intervention (i.e. treatment) and
      children who were never invited.

      Data from different sources will be used to answer the research question (intervention
      registries, health check-ups at school and Danish registries).
    

Detailed description: 
      Childhood obesity has been associated with increased risk of poorer mental health, later
      non-communicable lifestyle diseases (e.g. prediabetes, sleep apnea), and of continued excess
      body weight into adulthood. Multi-component family-centered lifestyle intervention seems to
      be the cornerstone in the treatment. However, only limited knowledge exists regarding weight
      development in children with obesity who decline to participate in such a lifestyle
      intervention. The aim of this study is therefore to investigate the long-term development in
      BMI z-score in children with obesity from 5 to 7 years of age who declined to participate in
      a lifestyle intervention. The development in BMI z-score for these children will be compared
      to children accepting the treatment and children who were never invited. A secondary aim is
      to investigate the potentially modifying effects of socioeconomic status (SES).

      The participants:

      This cohort study will include children from the city of Aarhus with a baseline visit between
      January 1st 2010 and June 30th 2020 children. The inclusion criteria are 1) 5-7 years of age
      and 2) obesity at baseline. Obesity will be defined by the International Obesity Task Force
      (IOTF) as BMI ≥ 30kg/m2 for age and gender. BMI z-score will be calculated be external
      reference population (WHO).

      The expected number of children included:

        -  App. 150-170 children with obesity who declined to participate in the Aarhus
           intervention (Declining group).

        -  App. 400 children with obesity accepted participation and received treatment in a
           multicomponent family-centered lifestyle intervention (intervention group).

        -  App. 700-800 children with obesity living in Aarhus, who were not invited to participate
           in the lifestyle intervention (Non-intervention group)

      Data sources:

        -  Participants will be identified using data from the municipality register.

        -  Anthropometrical data will be extracted from TM-Sund (Aarhus). TM-Sund is a database
           used to store data on anthropometrics obtained at health checks by specialized school
           nurses, Denmark.

        -  Data on SES, immigration and psychiatric illness will be obtained from Danish National
           registries.

      Statistics:

      A multiple imputation (MI) with chained equations will be applied to replace missing data
      regarding socioeconomic status and immigration, if missing data causes the models to lose
      substantial amount of observations, m=100. An adjusted mixed effects model with splines will
      be used to describe the development in BMI z-score for children declining participation and
      compare those to the reference and to the intervention groups. Knots will be placed at
      baseline and after ½, 1, 3 and 10.5 year. The model will be adjusted for age, BMI z-score,
      gender, family type, highest completed household education, equalized household income,
      immigration status, psychiatric diagnosis and psychiatric diagnosis (parents), zip code /
      distance to treatment center at baseline.

      Ethics & permissions:

      The local health ethics committee has approved the project, including data transfer (rec.no
      1-45-70-27-20).

      The project is internally reported to the University of Aarhus (rec no. 2916) The project has
      achieved approval from The Danish Data Protection Agency and the Principal Investigator has
      been granted accessed to register data from Statistics Denmark.

      A full plan for analytics has been completed.
    

Intervention name(s): Declining participation in the Aarhus intervention; Participation in the Aarhus intervention
Intervention type(s): Other; Behavioral
Intervention description(s): Each year a fraction of the children invited into the Aarhus intervention decline to participated.; A community-based multicomponent family-centered lifestyle intervention which included visits at home and weekly supervised physical activity. The intervention has a maximum duration of one year.
Observational model: Cohort
Time perspective: Other
Sampling method: Non-Probability Sample
Study population: 
        This study will include children with obesity from the city of Aarhus with a baseline visit
        between January 1st 2010 and June 30th 2020 children.
      
Keywords: Lifestyle intervention; refusal of treatment; effect, long term