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Trial registered on ANZCTR


Registration number
ACTRN12624000301561
Ethics application status
Approved
Date submitted
8/08/2023
Date registered
21/03/2024
Date last updated
21/03/2024
Date data sharing statement initially provided
21/03/2024
Type of registration
Retrospectively registered

Titles & IDs
Public title
The long-term effects of the Lekker Fit! intervention on physical fitness, physical activity, BMI-sds, and percent fat mass.
Scientific title
The long-term effects of a primary school-based overweight preventive intervention on physical fitness, physical activity, BMI-sds, and percent fat mass: a propensity score matching analysis among children within the Generation R Study cohort
Secondary ID [1] 310335 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
physical inactivity 331064 0
overweight 331065 0
Condition category
Condition code
Public Health 327854 327854 0 0
Other public health
Musculoskeletal 329369 329369 0 0
Normal musculoskeletal and cartilage development and function

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The Lekker Fit! (LF) intervention has been developed by the Sports department of the City of Rotterdam, the Netherlands in close collaboration with primary schools. It is a multi-component overweight preventive primary school-based intervention. The intervention targeted children aged 6/7 to 12/13 years old, primarily in socioeconomically disadvantaged neighborhoods. Since its development in 2005, the intervention has been scaled up to almost half of the primary schools in the city.

LF focuses on a healthy diet and healthy lifestyle rather than focusing directly on the reduction of overweight. The intervention targets individual behavior of children as well as their obesogenic environment and parental engagement . LF entails multiple components including but not limited to an additional third physical education lesson per week in comparison with regular school programs, professional physical education teachers instead of regular classroom teachers providing the physical education lessons, additional voluntary physical activity sessions outside school hours in cooperation with local sports clubs, special themed education on healthy lifestyle topics and, since 2013, the promotion of drinking water. The intervention is applied from grade 3-8 (6-to-12 years old) on primary schools, and since 2012 from grade 1-8 (4-to-12 years old).

For children in this study, we retrospectively considered them as the Lekker Fit! group if they have received the Lekker Fit! intervention for all primary school years, or as the regular school group, if they have received the intervention for < 6 months during their primary school. The mixed group contained children with an amount of LF exposure in between these groups. This data was received from the municipal records of the municipality of Rotterdam, the Netherlands. The school career data range is from the 23th of September 2003 to 29th of July in 2022 for the complete dataset, but for individual participants it entails the years in which they attended primary school.
Intervention code [1] 326733 0
Not applicable
Comparator / control treatment
The comparator group consists of children who were on regular primary schools. They did not received the LF intervention, but received educational programs as usual.
Control group
Active

Outcomes
Primary outcome [1] 335697 0
To assess physical fitness, a cycle ergometer test with electronic resistance was used (the Steep Ramp Test). With increments in resistance, the children keep pedaling until the child is not able to maintain pedaling.
We measured the highest achieved work rate in the test (WR,peak). We calculated the achieved proportion of highest predicted work rate (which was based on age- and gender- related population-based reference models). This was the composite primary outcome for physical fitness.
Timepoint [1] 335697 0
This measurement is taken at 13 years old, at a research site visit within the Generation R cohort Study.
Primary outcome [2] 335698 0
To assess physical activity, a self-report questionnaire data is used. The outcome measurement is the number of days (range 1-7) with at least one hour of physical activity. The question was a single-item question, included for the purpose of this study.
Timepoint [2] 335698 0
This measurement is taken at 13 years old, at a research site visit within the Generation R cohort Study.
Primary outcome [3] 335699 0
Body mass index was calculated based on measurements of body height and body weight. Body weight and body height were measured on a digital scale. Hereafter, age- and sex-specific standard deviation scores (SDS) for BMI were obtained from Dutch reference growth charts.
Timepoint [3] 335699 0
The measurement was taken both at 10 years old and at 14 years old during research visits within the Generation R cohort Study
Secondary outcome [1] 425233 0
This is actually also a primary outcome, but a maximum number of primary outcomes was reached for this registration.

Body composition was measured using a DXA scanner (iDXA, GE-Lunar, 2008, Madison, WI, USA), using enCORE software version 12.6. From these measurements, percent fat mass was obtained.
Timepoint [1] 425233 0
The measurement was taken both at 10 years old and at 14 years old during research visits within the Generation R cohort Study

Eligibility
Key inclusion criteria
- Being a child in the Generation R Study cohort in Rotterdam, the Netherlands
- Parental consent given for the transfer of school career data from the municipality of Rotterdam
- Successful coupling to school career data from the municipality of Rotterdam
- Data collected at the research site visit (13 years old) within the Generation R Study for at least one of the primary outcomes in the study
Minimum age
No limit
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- No parental consent given for the transfer of school career data from the municipality of Rotterdam
- No school career data available for retrospective intervention assignment
- No data collected, or no valid data available, on both of the primary outcomes in this study

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Both
Statistical methods / analysis
No calculations were performed regarding required sample size. In this study, children from an ongoing cohort study were included and/or excluded based on pre-determined criteria. Therefore, no active recruitment took place for this study.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
1/04/2002
Date of last participant enrolment
Anticipated
Actual
31/01/2006
Date of last data collection
Anticipated
Actual
8/07/2022
Sample size
Target
2000
Accrual to date
Final
3765
Recruitment outside Australia
Country [1] 25697 0
Netherlands
State/province [1] 25697 0
Rotterdam

Funding & Sponsors
Funding source category [1] 314540 0
Hospital
Name [1] 314540 0
Erasmus Medical Centre
Country [1] 314540 0
Netherlands
Primary sponsor type
Hospital
Name
Erasmus Medical Centre
Address
dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
Country
Netherlands
Secondary sponsor category [1] 316495 0
None
Name [1] 316495 0
Address [1] 316495 0
Country [1] 316495 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 313582 0
Medical Ethics Committee of the Erasmus Medical Centre, Rotterdam, the Netherlands
Ethics committee address [1] 313582 0
dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
Ethics committee country [1] 313582 0
Netherlands
Date submitted for ethics approval [1] 313582 0
Approval date [1] 313582 0
01/01/2002
Ethics approval number [1] 313582 0
MEC 198.782/2001/31

Summary
Brief summary
The Lekker Fit! intervention is a multi-component (physical activity and diet) intervention in primary schools in Rotterdam, the Netherlands. Due to scarce knowledge on long-term effects, this study aims to evaluate its long-term effects on physical fitness and physical activity among children after the transition to secondary schools.

The current LF intervention study is embedded within the Generation R Study cohort, a population-based prospective birth cohort study, in which children born between April 2002 and January 2006 are followed over time. Children are being invited for measurements and questionnaires at the research site every 3 or 4 years. Children from the Generation R Study are eligible for the LF intervention study if information is available on their primary school career through successful data transfer from the municipality of Rotterdam. Based on this data we retrospectively consider children as being part of the Lekker Fit! group or the regular school group.

Outcome measurements for physical fitness (highest achieved work rate at the Steep Ramp Test) and physical activity (the number of days per week with at least one hour of physical activity) are collected around the age of 13 years old during a research site visit in the Generation R Study. The study is expected to finish in the 2nd half of 2023.

Main contact persons for the study are M. Smit & F. Mölenberg & W. Jansen
[email protected]
Department of Public Health, Erasmus Medical Centre, Rotterdam, the Netherlands.
Trial website
Trial related presentations / publications
Public notes
Since this study is a cohort study since birth, there was no age limit in the first place.
The retrospectively taken outcome measurements were scheduled to conduct at certain ages, for example at 5 years old and 13 years old.
However, this was only a guideline in the cohort study. Measurements could also have been taken a year earlier or later. Therefore it is hard to mention an age limit.

Contacts
Principal investigator
Name 128634 0
Ms Wilma Jansen
Address 128634 0
dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
Country 128634 0
Netherlands
Phone 128634 0
+31612992019
Fax 128634 0
Email 128634 0
[email protected]
Contact person for public queries
Name 128635 0
Wilma Jansen
Address 128635 0
dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
Country 128635 0
Netherlands
Phone 128635 0
+31612992019
Fax 128635 0
Email 128635 0
[email protected]
Contact person for scientific queries
Name 128636 0
Wilma Jansen
Address 128636 0
dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
Country 128636 0
Netherlands
Phone 128636 0
+31612992019
Fax 128636 0
Email 128636 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This field will be updated soon after discussing it with the involved research team.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

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