Physical ActivityPHASARNCT03946241
Physical Activity in Schools After the Reform
An observational study of Physical Activity and Overweight, run by University of Southern Denmark at 1 site in Denmark.
Trial summary
In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 minutes of daily physical activity in the regular… Read more about this study
- Who is it for?
- Ages 6 to 17 years
- Conditions the study is for
- Physical Activity, Overweight, Physical Inactivity
- How many people
- 5,018 participants
- Where
- 1 siteDenmark
- Study dates
- 22 Aug 2017to 1 Jun 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 17 years
- All sexes
- No healthy volunteers
- Child
Study population: Pre-reform studies: School children in 1st to 9th grade (ages between 6 and 17 years). The participating children's parents or legal guardians. Post-reform studies: School children in 1st to 9th grade (ages between 6 and 17 years). The participating children's parents or legal guardians. Teachers, pedagogues, and headmasters from the same schools.
Who may be able to join
- Pre-reform study population:
- School children who been included in one of the four pre-reform studies.
- Post-reform study population:
- Children attended one of the public schools and age groups that had already been included in one of the four pre-reform studies.
Who cannot join
- School children that suffers from physical disabilities or injuries preventing physical activity.
Trial locations and contacts
1 site in 1 country.
Denmark1 site
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark
Odense, 5230
About this study
In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 minutes of daily physical activity in the regular school day. The overarching objective of the PHASAR study is to evaluate the implementation of this ambitious policy-driven physical activity promotion initiative and its potential effect on physical activity and overweight.
The PHASAR study provides a rare opportunity to evaluate the effectiveness of a nation-wide policy-driven school-based physical activity promotion initiative.
Read the detailed description
In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. The reform involved changes in several aspects of the school structure and content. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 minutes of daily physical activity during the regular school day. The overarching objective of the PHASAR study is to evaluate the implementation of this ambitious policy-driven physical activity promotion initiative and the possible effect on children's level of physical activity and overweight. Moreover, by applying improved accelerometry technology, the study aims to provide a detailed characterization of physical activity during the children's entire day including the school day.
The evaluation is divided into a quantitative effect evaluation and a combined quantitative and qualitative process evaluation. A total of 31 schools were enrolled and 2,683 pairs of accelerometers were handed out to school-aged children from 1st to 9th grade in the PHASAR study during the 2017/18 school year. The objectively measured physical activity data will be compared to repeated cross-sectional data collected in four historical school-based studies from 1998-2012. Body mass index data from 2012-2018 will be collected from The Child Database, which includes repeated cross-sectional assessments on approximately 100,000 children annually. In the absence of a control group, interrupted time-series analysis will be used to evaluate pre- and post-reform physical activity and body mass index levels and trends. A characterization of the school environment relevant for physical activity promotion on a political, environmental, organizational and individual level, as well as school implementation processes will be conducted to evaluate the implementation process. Data will be collected using interviews, surveys, document analyses and observations.
The PHASAR study provides a rare opportunity to evaluate the effectiveness of a nation-wide policy-driven school-based physical activity promotion initiative. The use of objectively measured pre- and post-reform physical activity and body mass index data combined with a characterization of the school implementation processes regarding the promotion of physical activity will provide a comprehensive source of information needed to evaluate the school reform.
- Conditions
- Physical Activity, Overweight, Physical Inactivity
- Keywords
- School children, Physical Activity, Accelerometry, Body mass index, Implementation, Policy
- Medical subject headings
- Motor Activity, Overweight, Sedentary Behavior
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Pre-reform study populations | Children from 1st to 9th grade (n ~ 2,600) from four different school-based studies collecting objective physical activity data. The four studies are 1) The European Youth Heart Study (EYHS) conducted in 1997-98, 2003-04 and 2009-10, 2) When Cities Move Children (WCMC) conducted in 2010 and 2012, 3) Childhood Health, Activity, and Motor Performance School Study Denmark (CHAMPS-DK) conducted in 2009, 2010 and 2012, and 4) School site, Play Spot, Active transport, Club fitness and Environment (SPACE) conducted in 2010 and 2012. A total of 44 schools where included in the studies. | |
| Post-reform study population | Children from 1st to 9th grade in 2017-18 from the same schools as included in the pre-reform research studies (n ~ 2,600). Two of the pre-reform research studies (CHAMPS-DK and SPACE) introduced PA promoting initiatives as part of the study. To minimize any influence from participation in these interventions we chose only to include and recruit participants from control schools from these studies. A total of 36 schools where invited and 31 subsequently accepted to participate. Parents and teachers of the children were included as well. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in levels of school time physical activity, reported as time spent moving, in a representative sample of school children before and after the school reform.
Objectively measured physical activity data are obtained via accelerometers mounted on the hip of the school children for a representative number of consecutive days. The school children's time spent moving will be longitudinally analysed on the school level (not class or individual level).
Measured: Pre-reform data have been collected between 1998 and 2012. Post-reform data have been collected during the school year 2017 to 2018.
Secondary outcomes (5)
Change in school children's BMI from the majority of all Danish public schools before, during, and after implementing the school reform.
Height and weight are obtained from the Child Database (Børnedatabasen), which is based on data from the mandatory examinations in schools by school nurses on three occasions during children's years in public school. The first measurement is conducted at the age of 6 to 7 years of age (in case of several measurements, the first was registered). The second measurement is conducted when children were between 9 and 13 years old (in case of several measurements, the measurement closest to the age of 11 was registered). The third measurement is conducted when children were 14 or 15 years old (in case of several measurements, the last was registered).
Measured: National BMI data have been obtained annually from 2011 and onwards. Thus, data from 2011 till 2018 will be utilized for this outcome.
Changes in BMI among school children before and after implementing the school reform.
School levels of changes in BMI will be compared in the pre- and post-reform study populations and analysed according to school levels of physical activity (child time spent moving).
Measured: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Changes in waist-to-height ratio among school children before and after implementing the school reform.
School levels of changes in waist-to-height ratio will be compared in the pre- and post-reform study populations (were available) and analysed according to school levels of physical activity (child time spent moving).
Measured: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Change in time spent in moderate to vigorous physical activity in school children during school time, leisure time and total time from before till after the school reform.
In order to investigate the effect of the school reform on health-related physical activity, change in time spent in moderate to vigorous physical activity (assessed by hip worn accelerometer) for school children before and after the school reform will the analysed.
Measured: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
The total amount of physical activity in school children during school time, leisure time and total time before and after the school reform.
The total amount of physical activity in school children during school time, leisure time and total time assessed using hip worn accelerometer will be reported as counts per minute for school children before and after the school reform.
Measured: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2019
- Study start22 Aug 2017
- Primary completion2 Dec 2019
- Study completion1 Jun 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Physical ActivityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Ecologic or community
- Time perspective
- Prospective
- Enrolment
- 5,018 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Southern Denmark
- Sponsor type
- University, hospital or other
- Collaborators
- TrygFonden, Denmark, University of Cambridge
- Responsible party
- Principal investigator, Anders Groentved, University of Southern Denmark
- Investigators
- Anders Grøntved, PhD, Principal investigator, University of Southern DenmarkJens Troelsen, Professor, Principal investigator, University of Southern Denmark
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03946241
- Sponsor's protocol ID
- 72682
- Other IDs
- 115606
- Acronym
- PHASAR
- Status last verified
- Apr 2026
- First submitted
- 6 May 2019
- Last updated
- 5 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD will be anonymised and handed over to the Danish National Archives. From there researchers can request the database for additional or new analyses.
Study at a glance
From the registry record, last updated by the sponsor on 5 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Physical Activity in Schools After the Reform
- ClinicalTrials.gov ID
- NCT03946241
- Acronym / sponsor ID
- PHASAR / 72682
- Conditions
- Physical Activity, Overweight, Physical Inactivity
- Keywords
- School children, Physical Activity, Accelerometry, Body mass index, Implementation, Policy
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 5,018 participants (actual)
- Lead sponsor
- University of Southern DenmarkUniversity, hospital or other
- Collaborators
- TrygFonden, Denmark, University of Cambridge
- Study start
- 22 Aug 2017 (actual)
- Primary completion
- 2 Dec 2019 (actual)
- Study completion
- 1 Jun 2022 (actual)
- First posted
- 10 May 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 minutes of daily physical activity in the regular school day. The overarching objective of the PHASAR study is to evaluate the implementation of this ambitious policy-driven physical activity promotion initiative and its potential effect on physical activity and overweight.
The PHASAR study provides a rare opportunity to evaluate the effectiveness of a nation-wide policy-driven school-based physical activity promotion initiative.
Detailed description
In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. The reform involved changes in several aspects of the school structure and content. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 minutes of daily physical activity during the regular school day. The overarching objective of the PHASAR study is to evaluate the implementation of this ambitious policy-driven physical activity promotion initiative and the possible effect on children's level of physical activity and overweight. Moreover, by applying improved accelerometry technology, the study aims to provide a detailed characterization of physical activity during the children's entire day including the school day.
The evaluation is divided into a quantitative effect evaluation and a combined quantitative and qualitative process evaluation. A total of 31 schools were enrolled and 2,683 pairs of accelerometers were handed out to school-aged children from 1st to 9th grade in the PHASAR study during the 2017/18 school year. The objectively measured physical activity data will be compared to repeated cross-sectional data collected in four historical school-based studies from 1998-2012. Body mass index data from 2012-2018 will be collected from The Child Database, which includes repeated cross-sectional assessments on approximately 100,000 children annually. In the absence of a control group, interrupted time-series analysis will be used to evaluate pre- and post-reform physical activity and body mass index levels and trends. A characterization of the school environment relevant for physical activity promotion on a political, environmental, organizational and individual level, as well as school implementation processes will be conducted to evaluate the implementation process. Data will be collected using interviews, surveys, document analyses and observations.
The PHASAR study provides a rare opportunity to evaluate the effectiveness of a nation-wide policy-driven school-based physical activity promotion initiative. The use of objectively measured pre- and post-reform physical activity and body mass index data combined with a characterization of the school implementation processes regarding the promotion of physical activity will provide a comprehensive source of information needed to evaluate the school reform.
Study design
- Observational model
- Ecologic or community
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Pre-reform study populations | – | –Children from 1st to 9th grade (n ~ 2,600) from four different school-based studies collecting objective physical activity data. The four studies are 1) The European Youth Heart Study (EYHS) conducted in 1997-98, 2003-04 and 2009-10, 2) When Cities Move Children (WCMC) conducted in 2010 and 2012, 3) Childhood Health, Activity, and Motor Performance School Study Denmark (CHAMPS-DK) conducted in 2009, 2010 and 2012, and 4) School site, Play Spot, Active transport, Club fitness and Environment (SPACE) conducted in 2010 and 2012. A total of 44 schools where included in the studies. |
| Post-reform study population | – | –Children from 1st to 9th grade in 2017-18 from the same schools as included in the pre-reform research studies (n ~ 2,600). Two of the pre-reform research studies (CHAMPS-DK and SPACE) introduced PA promoting initiatives as part of the study. To minimize any influence from participation in these interventions we chose only to include and recruit participants from control schools from these studies. A total of 36 schools where invited and 31 subsequently accepted to participate. Parents and teachers of the children were included as well. |
Who may qualify
- Ages
- 6 to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- Pre-reform studies: School children in 1st to 9th grade (ages between 6 and 17 years). The participating children's parents or legal guardians. Post-reform studies: School children in 1st to 9th grade (ages between 6 and 17 years). The participating children's parents or legal guardians. Teachers, pedagogues, and headmasters from the same schools.
Key inclusion criteria (4 listed)
- School children who been included in one of the four pre-reform studies.
- Children attended one of the public schools and age groups that had already been included in one of the four pre-reform studies.
Key exclusion criteria (1 listed)
- School children that suffers from physical disabilities or injuries preventing physical activity.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in levels of school time physical activity, reported as time spent moving, in a representative sample of school children before and after the school reform.
Time frame: Pre-reform data have been collected between 1998 and 2012. Post-reform data have been collected during the school year 2017 to 2018.
Objectively measured physical activity data are obtained via accelerometers mounted on the hip of the school children for a representative number of consecutive days. The school children's time spent moving will be longitudinally analysed on the school level (not class or individual level).
5 secondary outcomes
Change in school children's BMI from the majority of all Danish public schools before, during, and after implementing the school reform.
Time frame: National BMI data have been obtained annually from 2011 and onwards. Thus, data from 2011 till 2018 will be utilized for this outcome.
Changes in BMI among school children before and after implementing the school reform.
Time frame: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Changes in waist-to-height ratio among school children before and after implementing the school reform.
Time frame: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Change in time spent in moderate to vigorous physical activity in school children during school time, leisure time and total time from before till after the school reform.
Time frame: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
The total amount of physical activity in school children during school time, leisure time and total time before and after the school reform.
Time frame: Data will be obtained from the pre-reform research studies in the years leading up to the school reform and the data collected during the school years 2017/18 and 2018/19.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 May 2026.
- Individual participant dataSharing planned: Yes. IPD will be anonymised and handed over to the Danish National Archives. From there researchers can request the database for additional or new analyses.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anders Grøntved, PhD principal investigator
University of Southern Denmark
Jens Troelsen, Professor principal investigator
University of Southern Denmark
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Physical Activity and Overweight, run by University of Southern Denmark at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in levels of school time physical activity, reported as time spent moving, in a representative sample of school children before and after the school reform. (time frame: Pre-reform data have been collected between 1998 and 2012. Post-reform data have been collected during the school year 2017 to 2018.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 May 2026.