Commitment-enhancing interventions promote arsenic-safe water consumption in Bangladesh
Naturally occurring arsenic in drinking water poses a threat to human health. Many safe water alternatives to contaminated shallow wells have been installed in Bangladesh. However, these are often not being used. This project aimed at improving the effectiveness of an information intervention to promote the use of existing safe water options with theory-based and evidence-based behaviour change techniques. The commitment-enhancing techniques (reminders, implementation intentions and public commitment) led to up to 50% increased behaviour change compared to information alone. The behaviour change effect was mediated by increasedcommitment strength.
Context Geogenic contamination of drinking water, such as arsenic, is associated with chronic disease and increased mortality. Nowhere is the issue as severe as in Bangladesh, where millions of wells are contaminated. Approximately 20 million Bangladeshi are at risk of drinking water with elevated arsenic relative to the national standard of 50 micrograms per litre. Although safe water options (e.g. deep wells) are often in walking distance, and well-sharing among neighbours with safe wells has been encouraged, many people still drink water from contaminated or untested wells.
Objectives The main goal of this project was to promote safe water consumption with theory-based and evidence-based behaviour change techniques (BCTs). Specific objectives were:
To assess current water consumption practices and the behavioural factors associated with these practices.
To design, implement, and evaluate theory-based and evidence-based BCTs to promote safe water consumption.
Activities Step 1 & 2: Identify, measure, and determine behavioural factors of safe water consumption:
A baseline survey about safe water consumption practices and its behavioural determinants was conducted in 710 households in November and December 2010 in several villages of Manikganj and Monoharganj districts, Bangladesh.
Manikganj has lower rates of contaminated wells, wherefore sharing of neighbouring arsenic-safe shallow wells was promoted. In Monoharganj, where there are almost no safe shallow wells, the use of available arsenic-safe deep wells was promoted.
The behavioural factors influencing the use (vs. non-use) of arsenic-safe water options were specified by means of a logistic regression. The strongest associations were found for commitment strength to use safe water options and the descriptive norm (perceptions of how many others collect safe water).
Step 3: Select behavior change techniques (BCTs) and design behavior change strategies to promote safe water consumption:
Three BCTs expected to promote the key factors of safe water consumption (commitment strength and the descriptive norm) were selected. These were (1) reminders, (2) implementation intentions (imps; a concrete plan, when and where to collect safe water), and (3) public commitment.
The BCTs were combined into three interventions with information about arsenic – reminders+information, imps+reminders+information,
public_commitment+imps+reminders+information - and compared to information alone.
Step 4: Implement and evaluate behavior change strategies:
The interventions’ effectiveness was assessed through two before-and-after cluster-randomised controlled trials (one in each district).
The interventions were delivered by trained health promoters of our partner organisations.
A follow-up survey on safe water consumption practices, behavioural determinants and the interventions’ evaluation was conducted in April 2011, with the same households as at baseline.
Up to 65% switching to arsenic-safe wells was observed in the intervention groups compared to up to 18% well-switching in the information-only group.
The behaviour change effects increased when more commitment-enhancing BCTs were added.
The intervention effects on behaviour change were evoked through increases in commitment strength.
There were unclear results about public commitment. Whereas the intervention that included this BCT was the most effective to promote switching to deep wells, this intervention was not more successful than information alone for promoting sharing of neighbouring safe wells.
Conclusion Commitment-enhancing interventions can substantially increase the effects of information to promote safe water consumption.
Developing and testing theory-based and evidence-based interventions to promote switching to arsenic-safe wells in Bangladesh
Millions of people in Bangladesh drink arsenic-contaminated water despite increased awareness of consequences to health. Theory-based and evidence-based interventions are likely to have greater impact on people switching to existing arsenic-safe wells than providing information alone. To test this assumption, we first developed interventions based on an empirical test of the Risk, Attitudes, Norms, Abilities and Self-regulation (RANAS) model of behaviour change. In the second part of this study, a cluster-randomised controlled trial revealed that in accordance with our hypotheses, information alone showed smaller increases in switching to arsenic-safe wells than information with reminders or information with reminders and implementation intentions.
Inauen, J.; Mosler, H.-J. (2014) Developing and testing theory-based and evidence-based interventions to promote switching to arsenic-safe wells in Bangladesh, Journal of Health Psychology, 19(12), 1483-1498, doi:10.1177/1359105313493811, Institutional Repository
The role of commitment strength in enhancing safe water consumption: mediation analysis of a cluster-randomized trial
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 (BCTs) 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 BCTs. Methods. Randomly selected households (N = 340) of Monoharganj, Bangladesh, 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 BCTs - public self-commitment, implementation intentions, and reminders - increased the behaviour change effects of information by up to 50%. Mediation analyses confirmed that the BCTs 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. BCTs that alter behavioural intentions and commitment strength proved highly effective at enhancing the behaviour change effects of information alone.
Inauen, J.; Tobias, R.; Mosler, H.-J. (2014) The role of commitment strength in enhancing safe water consumption: mediation analysis of a cluster-randomized trial, British Journal of Health Psychology, 19(4), 701-719, doi:10.1111/bjhp.12068, Institutional Repository
Predicting water consumption habits for seven arsenic-safe water options in Bangladesh
Background: In Bangladesh, 20 million people are at the risk of developing arsenicosis because of excessive arsenic intake. Despite increased awareness, many of the implemented arsenic-safe water options are not being sufficiently used by the population. This study investigated the role of social-cognitive factors in explaining the habitual use of arsenic-safe water options. Methods: Eight hundred seventy-two randomly selected households in six arsenic-affected districts of rural Bangladesh, which had access to an arsenic-safe water option, were interviewed using structured face-to-face interviews in November 2009. Habitual use of arsenic-safe water options, severity, vulnerability, affective and instrumental attitudes, injunctive and descriptive norms, self-efficacy, and coping planning were measured. The data were analyzed using multiple linear regressions. Results. Linear regression revealed that self-efficacy (B = 0.42, SE = .03, p < .001), the instrumental attitude towards the safe water option (B = 0.24, SE = .04, p < .001), the affective attitude towards contaminated tube wells (B = −0.04, SE = .02, p = .024), vulnerability (B = −0.20, SE = .02, p < .001), as well as injunctive (B = 0.08, SE = 0.04, p = .049) and descriptive norms (B = 0.34, SE = .03, p < .001) primarily explained the habitual use of arsenic-safe water options (R2 = 0.688). This model proved highly generalizable to all seven arsenic-safe water options investigated, even though habitual use of single options were predicted on the basis of parameters estimated without these options. Conclusions. This general model for the habitual use of arsenic-safe water options may prove useful to predict other water consumption habits. Behavior-change interventions are derived from the model to promote the habitual use of arsenic-safe water options.
Acceptance and use of eight arsenic-safe drinking water options in Bangladesh
Arsenic contamination of drinking water is a serious public health threat. In Bangladesh, eight major safe water options provide an alternative to contaminated shallow tubewells: piped water supply, deep tubewells, pond sand filters, community arsenic-removal, household arsenic removal, dug wells, well-sharing, and rainwater harvesting. However, it is uncertain how well these options are accepted and used by the at-risk population. Based on the RANAS model (risk, attitudes, norms, ability, and self-regulation) this study aimed to identify the acceptance and use of available safe water options. Cross-sectional face-to-face interviews were used to survey 1,268 households in Bangladesh in November 2009 (n = 872), and December 2010 (n = 396). The questionnaire assessed water consumption, acceptance factors from the RANAS model, and socioeconomic factors. Although all respondents had access to at least one arsenic-safe drinking water option, only 62.1% of participants were currently using these alternatives. The most regularly used options were household arsenic removal filters (92.9%) and piped water supply (85.6%). However, the former result may be positively biased due to high refusal rates of household filter owners. The least used option was household rainwater harvesting (36.6%). Those who reported not using an arsenic-safe source differed in terms of numerous acceptance factors from those who reported using arsenic-safe sources: non-users were characterized by greater vulnerability; showed less preference for the taste and temperature of alternative sources; found collecting safe water quite time-consuming; had lower levels of social norms, self-efficacy, and coping planning; and demonstrated lower levels of commitment to collecting safe water. Acceptance was particularly high for piped water supplies and deep tubewells, whereas dug wells and well-sharing were the least accepted sources. Intervention strategies were derived from the results in order to increase the acceptance and use of each arsenic-safe water option.
Enhancing arsenic mitigation in Bangladesh: findings from institutional, psychological, and technical investigations
As part of a trans-disciplinary research project, a series of surveys and interventions were conducted in different arsenic-affected regions of rural Bangladesh. Surveys of institutional stakeholders identified deep tubewells and piped water systems as the most preferred options, and the same preferences were found in household surveys of populations at risk. Psychological surveys revealed that these two technologies were well-supported by potential users, with self-efficacy and social norms being the principal factors driving behavior change. The principal drawbacks of deep tubewells are that installation costs are too high for most families to own private wells, and that for various socio-cultural-religious reasons, people are not willing to walk long distances to access communal tubewells. In addition, water sector planners have reservations about greater exploitation of the deep aquifer, out of concern for current or future geogenic contamination. Groundwater models and field studies have shown that in the great majority of the affected areas, the risk of arsenic contamination of deep groundwater is small; salinity, iron, and manganese are more likely to pose problems. These constituents can in some cases be avoided by exploiting an intermediate depth aquifer of good chemical quality, which is hydraulically and geochemically separate from the arsenic-contaminated shallow aquifer. Deep tubewells represent a technically sound option throughout much of the arsenic-affected regions, and future mitigation programs should build on and accelerate construction of deep tubewells. Utilization of deep tubewells, however, could be improved by increasing the tubewell density (which requires stronger financial support) to reduce travel times, by considering water quality in a holistic way, and by accompanying tubewell installation with motivational interventions based on psychological factors. By combining findings from technical and social sciences, the efficiency and success of arsenic mitigation in general – and installation of deep tubewells in particular – can be significantly enhanced.
Johnston, R.; Hug, S. J.; Inauen, J.; Khan, N. I.; Mosler, H.-J.; Yang, H. (2014) Enhancing arsenic mitigation in Bangladesh: findings from institutional, psychological, and technical investigations, Science of the Total Environment, 488(1), 477-483, doi:10.1016/j.scitotenv.2013.11.143, Institutional Repository
Mechanisms of behavioural maintenance: longterm effects of theory-based interventions to promote safe water consumption
Theory-based interventions can enhance people’s safe water consumption, but the sustainability of these interventions and the mechanisms of maintenance remain unclear. We investigated these questions based on an extended theory of planned behaviour. Seven hundred and ten (445 analysed) randomly selected households participated in two cluster-randomised controlled trials in Bangladesh. Study 1 promoted switching to neighbours’ arsenic-safe wells, and Study 2 promoted switching to arsenic-safe deep wells. Both studies included two intervention phases. Structured interviews were conducted at baseline (T1), and at 1-month (T2), 2-month (T3) and 9-month (T4) follow-ups. In intervention phase 1 (between T1 and T2), commitment-based behaviour change techniques – reminders, implementation intentions and public commitment – were combined with information and compared to an information-only control group. In phase 2 (between T2 and T3), half of each phase 1 intervention group was randomly assigned to receive either commitment-based techniques once more or coping planning with reminders and information. Initial well-switching rates of up to 60% significantly declined by T4: 38.3% of T2 safe water users stopped consuming arsenic-safe water. The decline depended on the intervention. Perceived behavioural control, intentions, commitment strength and coping planning were associated with maintenance. In line with previous studies, the results indicate that commitment and reminders engender long-term behavioural change.