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The role of commitment strength in enhancing safe water consumption: Mediation analysis of a cluster‐randomized trial
Author(s) -
Inauen Jennifer,
Tobias Robert,
Mosler HansJoachim
Publication year - 2014
Publication title -
british journal of health psychology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 88
eISSN - 2044-8287
pISSN - 1359-107X
DOI - 10.1111/bjhp.12068
Subject(s) - mediation , psychology , theory of planned behavior , intervention (counseling) , acceptance and commitment therapy , moderated mediation , behavior change , social psychology , randomized controlled trial , structural equation modeling , cluster (spacecraft) , medicine , control (management) , management , surgery , psychiatry , political science , law , economics , statistics , mathematics , computer science , programming language
Objectives The objectives of this study were to investigate the importance of commitment strength in the theory of planned behaviour ( TPB ) and to test whether behaviour change techniques ( BCT s) aimed at increasing commitment strength indeed promote switching to arsenic‐safe wells by changing commitment strength. Design A cluster‐randomized controlled trial with four arms was conducted to compare an information‐only intervention to information plus one, two, or three commitment‐enhancing BCT s. Methods Randomly selected households ( N = 340) of M onoharganj, B angladesh, in seven geographically separate areas, whose members were drinking arsenic‐contaminated water at baseline and had access to arsenic‐safe wells, participated in this trial. The areas were randomly allocated to the four intervention arms. Water consumption behaviour, variables of the TPB , commitment strength, and socio‐demographic characteristics were assessed at baseline and at 3‐month follow‐up by structured face‐to‐face interviews. Mediation analysis was used to investigate the mechanisms of behaviour change. Results Changes in commitment strength significantly increased the explanatory power of the TPB to predict well‐switching. Commitment‐enhancing BCT s – public self‐commitment, implementation intentions, and reminders – increased the behaviour change effects of information by up to 50%. Mediation analyses confirmed that the BCT s indeed increased well‐switching by increasing commitment strength. Unexpectedly, however, mediation via changes in behavioural intentions was the strongest mechanism of the intervention effects. Conclusions Commitment is an important construct to consider in water‐ and health‐related behaviour change and may be for other health behaviours as well. BCT s that alter behavioural intentions and commitment strength proved highly effective at enhancing the behaviour change effects of information alone.Statement of contribution What is already known on this subject? Millions of people drink contaminated water even if they have access to safe water alternatives and despite increased awareness of the consequences to health. The theory of planned behaviour ( TPB ) and commitment strength are predictive of safe water consumption. The potentially commitment‐enhancing behaviour change techniques ( BCT s) – reminders, implementation intentions, and public self‐commitment – can promote health behaviours, including safe water consumption. What does this study add?Changes in commitment strength significantly added to the prediction of switching to arsenic‐safe wells by the TPB . Information‐plus‐BCTs aimed at increasing commitment strength led to >50% more well‐switching than information alone. Behaviour change effects of the BCT s were mediated by changes in commitment strength and behavioural intentions.