Explaining Low Rates of Sustained use of Siphon Filters: Evidence from Follow-up of a Randomized Controlled Trial in Bangladesh
Najnin, N., Arman, S., Abedin, J., Unicomb, L., Levine, D., Mahmud, M., Leder, K., Yeasmin, F., Luoto, J., Albert, J., Luby, S. (2015). Explaining Low Rates of Sustained use of Siphon Filters: Evidence from Follow-up of a Randomized Controlled Trial in Bangladesh. Tropical Medicine & International Health. 20,4: 471-483.
Objective: To assess sustained siphon filter usage among a low-income population in Bangladesh and study relevant motivators and barriers.
Methods: After a randomised control trial in Bangladesh during 2009, 191 households received a siphon water filter along with educational messages. Researchers revisited households after 3 and 6 months to assess filter usage and determine relevant motivators and barriers. Regular users were defined as those who reported using the filter most of the time and were observed to be using the filter at follow-up visits. Integrated behavioural model for water, sanitation and hygiene (IBM-WASH) was used to explain factors associated with regular filter use.
Results: Regular filter usage was 28% at the 3-month follow-up and 21% at the 6-month follow-up. Regular filter users had better quality water at the 6-month, but not at the 3-month visit. Positive predictors of regular filter usage explained through IBM-WASH at both times were willingness to pay >US$1 for filters, and positive attitude towards filter use (technology dimension at individual level); reporting boiling drinking water at baseline (psychosocial dimension at habitual level); and Bengali ethnicity (contextual dimension at individual level). Frequently reported barriers to regular filter use were as follows: considering filter use an additional task, filter breakage and time required for water filtering (technology dimension at individual level).
Conclusion: The technological, psychosocial and contextual dimensions of IBM-WASH contributed to understanding the factors related to sustained use of siphon filter. Given the low regular usage rate and the hardware-related problems reported, the contribution of siphon filters to improving water quality in low-income urban communities in Bangladesh is likely to be minimal.