TY - JOUR
T1 - Evaluating the Let’s Move It intervention programme theory for adolescents’ physical activity: Theorised psychosocial mechanisms of behavioural change
AU - Palsola, Minttu
AU - Araújo-Soares, Vera
AU - Hardeman, Wendy
AU - Haukkala, Ari
AU - Toivo, Matti
AU - Heino, Juhani
AU - Sniehotta, Falko
AU - Sund, Reijo
AU - Vasankari, Tommi
AU - Hankonen, Nelli
N1 - Data availability statement: The data that support the findings of this study are available in the Finnish Social Science Data Archive at http://urn.fi/urn:nbn:fi:fsd:T-FSD3446, reference number FSD3446.
Funding information: Opetus- ja kulttuuriministeriö. Grant Number: OKM/81/626/2014; Academy of Finland. Grant Numbers: 285283, 304114
PY - 2025/2
Y1 - 2025/2
N2 - Objectives: Behaviour change theories have extensively been used in health behaviour change interventions and their programme theories. However, they are rarely evaluated in randomized field studies. The Let's Move It intervention targeted various psychosocial constructs to increase adolescents' physical activity. A theory-based process evaluation aiming to illuminate the trial findings as well as to test the programme theory used is conducted. Specifically, we investigate whether the intervention influenced the theorized determinants of change immediately post-intervention and after 1 year, and whether these determinants were associated with changes in physical activity. Design: A cluster-randomized controlled trial (n = 1166). Methods: We measured theorized determinants with self-report, and physical activity (PA) with accelerometry and self-report. The effects are evaluated with repeated measures ANOVA and regression models. Results: No changes were detected in most theorized determinants but intervention arm reported higher enactment of behaviour change techniques used during intervention immediately post-intervention and lower descriptive norms for PA throughout. Autonomous motivation was associated with PA immediately post-intervention. Conclusions: The lack of intervention effects may be due to many factors, for example insensitive measures, ceiling effects. However, reporting these null effects advances understanding of behaviour change processes. We introduce methodologic possibilities for future intervention programme theory evaluation efforts.
AB - Objectives: Behaviour change theories have extensively been used in health behaviour change interventions and their programme theories. However, they are rarely evaluated in randomized field studies. The Let's Move It intervention targeted various psychosocial constructs to increase adolescents' physical activity. A theory-based process evaluation aiming to illuminate the trial findings as well as to test the programme theory used is conducted. Specifically, we investigate whether the intervention influenced the theorized determinants of change immediately post-intervention and after 1 year, and whether these determinants were associated with changes in physical activity. Design: A cluster-randomized controlled trial (n = 1166). Methods: We measured theorized determinants with self-report, and physical activity (PA) with accelerometry and self-report. The effects are evaluated with repeated measures ANOVA and regression models. Results: No changes were detected in most theorized determinants but intervention arm reported higher enactment of behaviour change techniques used during intervention immediately post-intervention and lower descriptive norms for PA throughout. Autonomous motivation was associated with PA immediately post-intervention. Conclusions: The lack of intervention effects may be due to many factors, for example insensitive measures, ceiling effects. However, reporting these null effects advances understanding of behaviour change processes. We introduce methodologic possibilities for future intervention programme theory evaluation efforts.
KW - behaviour change technique enactment
KW - intervention evaluation
KW - physical activity
KW - programme theory
KW - randomized controlled trial
KW - reasoned action approach
KW - self-determination theory
UR - http://www.scopus.com/inward/record.url?scp=85204776724&partnerID=8YFLogxK
U2 - 10.1111/bjhp.12744
DO - 10.1111/bjhp.12744
M3 - Article
SN - 1359-107X
VL - 30
JO - British Journal of Health Psychology
JF - British Journal of Health Psychology
IS - 1
M1 - e12744
ER -