Unleashing the power of peers for health

PEER-ACTIVE: a school based study on physical activity

Institute for Health and Consumer Protection Joint Research Centre

In collaboration with the University of Cambridge and UST Varese (Italy)

Peer-Active Project

WHY?

• tackling obesity problem in adolescents

HOW?

developing adequate tools for changing the behavior of children towards a healthier lifestyle

promoting physical activity (PA) by taking advantage of existing

networks of friends among pupils

STUDY SITE

MILAN

LUGANO

LAGO MAGGIORE

Angera

Sesto Calende

MILAN

Winter Phase

Spring Phase

Sample size

=180

=173

Ispra

Comabbio

Varano Borghi

Laveno

Golasecca Vergiat

Malgesso

Mercallo

21+19

24 18+2

18

13

14

18

24+26

39

Taino

14+12 3x19

Cimbr

2

• Physical activity is measured through accelerometers

• Kids receive weekly points based on physical performance

• Points can be exchanged with rewards at the end of the experiment

• non-invasive • weight: 27 gr (3.8cm x 3.7

cm x 1.8 cm)

Experimental treatments

• Social reward treatment: reward according to others' (e.g., friends) performance

• Individual reward treatment: reward according to individual performance.

• Baseline treatment: reward not based on physical activity

•Friendship network construction for social treatments

Improving the effectiveness of social schemes by pairing kids on the basis of their friendship level

Social treatment

Social treatment 1: PEER

• Child's reward depends on the performance of two other peers, while its own performance affects two other children's rewards.

Social treatment 2: RECIPROCITY

• Providers are also receivers. The performance of each child has an impact on the rewards of other two members

Social treatment 3: GROUP

• All the three members of the closed team accumulate points together, which are then equally distributed among them

Individual treatment

• Children receive points according to their own physical performance

Baseline Treatment

• Children receive points according to a lottery, not related to their physical performance

TU

GAME

DATA COLLECTION

WEEKLY FEEDBACK

REWARD

Duration 7 weeks x 2 periods

Peer-Active Facts Measuring the PA of more than 350 students from 18 different 5th

grade classes around the area of Varese from February to May 2014

Recording more than 140,000 activity hours in total (excluding sleep time), corresponding to 380 hours per student or 13,5 hours per day and student

Collecting one of the most long-lasting (almost 2 months) datasets in the PA literature

Preliminary Results

Q1: Individual vs Social treatments

Baseline

Q2: Are there any gender differences within treatments?

Q2: Are there any gender differences within treatments? M

F

Preliminary Conclusions (TBC) • All Conditions are effective in promoting PA

• Social incentives appear more effective than individual

• Reciprocity and Group Conditions appear to have a greater

impact on children's PA • Responses to social incentives are probably affected by

gender.

• (Un)-expected results: Increased responsibility and group feeling

• Full data exploitation: school networks, personality tests, weather conditions, holidays and weekend effect...

Science building bridges with Society! Final event at the JRC: a day in the field (lab)!

Thank you!

Your peer comments are more than (effective and) welcome!

really NOT understandable

rho .15572069 (fraction of variance due to u_i)

sigma_e 6.4460555

sigma_u 2.7683699

_cons 17.44445 .6412551 27.20 0.000 16.18761 18.70129

pmvf .1040799 .008259 12.60 0.000 .0878926 .1202672

pmvt0 .0780352 .0086584 9.01 0.000 .0610651 .0950053

phase 2.298674 .3327087 6.91 0.000 1.646577 2.950771

fem -2.637605 .3207773 -8.22 0.000 -3.266317 -2.008893

5 1.692971 .4957044 3.42 0.001 .7214082 2.664534

4 1.676272 .5535943 3.03 0.002 .5912471 2.761297

3 .4052913 .5245524 0.77 0.440 -.6228124 1.433395

2 .5018683 .4751745 1.06 0.291 -.4294565 1.433193

cnd_n

pmv Coef. Std. Err. z P>|z| [95% Conf. Interval]

corr(u_i, X) = 0 (assumed) Prob > chi2 = 0.0000

Wald chi2(8) = 368.77

overall = 0.0888 max = 42

between = 0.2624 avg = 32.5

R-sq: within = 0.0175 Obs per group: min = 8

Group variable: id_code Number of groups = 348

Random-effects GLS regression Number of obs = 11312

. xtreg pmv i.cnd_n fem phase pmvt0 pmvf, re

Males Females