A Randomized-Controlled Lifestyle Intervention to Increase Physical Activity Levels in Adolescents
Condition: Life Style, Healthy; Life Style
Study type: Interventional

Summary: 
      Students at the age of 14-16 years will be randomized to one intervention arm or one control
      arm in a 1:1 ratio. Participants of both groups receive a fitness tracker to count the amount
      of their steps taken. The participants of the intervention arm will commit themselves to a
      personal goal of steps taken by means of a commitment contract. Achievement of the goal will
      be rewarded with financial incentives to fulfill the requirements of proper reward medium,
      according to the Induced Value Theory (Smith, 1976).

      The duration of the intervention will be 1 year; incentives are provided for 6 months, the
      remaining 6 months are the follow-up period.

      The hypothesis is that intensified motivational strategies like the provision of commitment
      contracts and nudges are effective in increasing the number of steps taken per month compared
      to a control group.
    

Detailed description: 
      Adolescents age 14 to 16 years visiting schools throughout Tyrol, Austria will be randomized
      to one intervention arm or a control arm on a class-wise level in a 1:1 ratio. Participants
      will be invited by the Department of Education in Tyrol and schools will be contacted
      directly. At the baseline examination cardiovascular risk profiles (including laboratory
      analysis; anthropometry; a standardized medical interview; and blood pressure, bioelectrical
      impedance and pulse-wave velocity measurements) are determined and results are communicated
      in an individual discussion of results.

      Afterwards, participants of both groups receive a fitness tracker to count the amount of
      their steps taken. The participants of the intervention arm will commit themselves to a
      personal goal of steps taken by means of a commitment contract. Achievement of the goal will
      be rewarded with financial incentives to fulfill the requirements of proper reward medium,
      according to the Induced Value Theory (Smith, 1976) and nudges (reminders) will be provided
      to increase motivation.

      The duration of the intervention will be 1 year; incentives are provided for 6 months, the
      remaining 6 months are the follow-up period. After 1 year a follow-up examination will be
      conducted. Economic experiments on time and risk preferences are furthermore carried out at
      baseline.

      The hypothesis is that intensified motivational strategies like the provision of commitment
      contracts and nudges are effective in increasing the number of steps taken per month compared
      to a control group.
    

Intervention name(s): Promotion of physical activity
Intervention type(s): Behavioral
Intervention description(s): Provision of motivational stimuli (commitment contracts, nudges, financial incentives) to increase amount of steps taken
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Lifestyle Intervention; Adolescents; Health Behavior; Financial Incentives; Commitment Contract; Nudges; Cardiovascular Risk Reduction; Primoridal Prevention; Physical Activity