Plain English Summary
Background and study aims
Access to clean water plays a vital role in preventing diarrheal diseases, especially in rural settings in developing countries. Because piped water may not be possible in these areas for many years, water purification products have been developed and tested in order to provide people with access to clean drinking water. Water purification products have been proven to be one of the most cost-effective methods to provide access to clean water. However, purchase and usage rates of these water purification products are much lower than expected. Water purification products have been distributed freely or sold at a highly subsidized price and each approach has its advantages and disadvantages. As a result, various social marketing approaches are being explored in order to increase purchase and usage rates of water purification products. This study aims to investigate whether or not a free trial approach will increase the number of users who will purchase and use Klorfasil, a chlorine-based water purification product, in rural communities in Haiti. It is plausible that users need to experiment with the product before being convinced of its usefulness.
Who can participate?
Men and women ages 18 and above are able to participate in our study. Participants will be excluded if they have bought Klorfasil and/or use any other water purification product besides Aquatabs, a chlorine tablet often distributed by the government or other non-governmental organizations.
What does the study involve?
Participants are randomly allocated to one of two groups. All participants will be surveyed about their knowledge, attitudes, and water treatment practices. Afterwards, they are given a brief information session about the benefits of using Klorfasil to make their water safe to drink. One group will be offered to try out Klorfasil for free for 1 month before deciding whether to purchase Klorfasil while the other group will not get the free trial. We randomly assigned which villages will receive a free trial of Klorfasil in order to prevent information leakage. Participants who purchased Klorfasil will be followed up 30, 60, and 180 days after their initial purchase to assess their experience using Klorfasil.
What are the possible benefits and risks of participating?
There are immediate and long-term benefits for the participants in that they all receive information about the importance of water purification and some participants will be able to purify their water for free for a month. The results of this study may be able to inform policy makers, researchers, and program managers of the strengths and weaknesses of using such a free-trial approach to increase purchase and usage rates of water purification products in resource-limited rural settings. There are no known risks to participate. The chemical compound in Klorfasil, sodium dichloroisocyanurate (NaDCC), is recognized by the World Health Organization as a safe and effective means of reducing diarrheal diseases. All participants are given an opportunity to purchase Klorfasil.
Where is the study run from?
This study is being run by Taipei Medical University with the assistance of Medical Missionaries, a local non-governmental organization. The study takes place among households living in 7 villages surrounding St. Joseph’s Clinic in Thomassique, Haiti. The villages are approximately 90 minutes from the clinic by motorcycle.
When is the study starting and how long is it expected to run for?
May 2016 to December 2016
How long will the trial be recruiting participants for and who is funding the study?
This study was funded by Taipei Medical University. The recruiting process will take 1 month. The participants who purchased Klorfasil will be followed afterwards for 180 days.
Who is the main contact?
Prof. Feng-Jen Tsai, email@example.com
Prof Feng-jen Tsai
250 Wu-Hsing Street
Does a free-trial approach increase purchase and use of a water purification product in rural Haiti? A cluster randomized control trial.
A free trial approach would increase purchase of Klorfasil and that users in the free-trial group would have better water treatment outcomes than the control group
Taipei Medical University Joint Institutional Review Board, 20/04/2016, TMU IJIRB No. N201603084
Single-blinded cluster randomized control trial
Primary study design
Secondary study design
Cluster randomised trial
Patient information sheet
Water purification using chlorination to prevent diarrhea
We enrolled households from villages in Thomassique, Haiti, to evaluate purchase and water treatment outcomes over 6-months of follow-up. Clusters of households were randomized to free trial (intervention) or cost-sharing group (control). Households were surveyed and informed of the importance of treating their water and then offered to purchase Klorfasil. Households in the intervention group were given 30 days free use of Klorfasil before deciding to purchase. Households that purchased Klorfasil were followed up 30, 60, and 180 days after baseline survey.
Primary outcome measure
Decision to purchase Klorfasil at baseline and 180 days
Secondary outcome measures
Residual free chlorine (RFC) levels of stored drinking water at baseline and 30, 60, and 180 days after baseline. Water with RFC levels of 0.5 mg/l and above is deemed "treated" while water with RFC<0.5 mg/l is deemed "untreated"
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged 18 years and over
2. Never used Klorfasil or another household water treatment product before (with the exception of Aquatabs)
Target number of participants
497 households in 7 clusters
Participant exclusion criteria
1. Under the age of 18 years
2. Used Klorfasil or another water purification product before
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Saint Joseph Clinic
investigator initiated and funded
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
We plan to publish the result on SCI/SSCI journal in 2018.
IPD sharing statement
The datasets generated during and/or analysed during the current study are available upon request.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)
Between May 1, 2014 and December 31, 2014, 497 households in 7 clusters were enrolled and randomly assigned an intervention or control group. 67.3% of households in the free-trial group (intervention) compared to 78.3% of household in the cost-sharing group purchased Klorfasil. After controlling for confounders, households with higher economic status were 4.5 times more likely to purchase Klorfasil (AOR 4.631, 95% CI = 2.004-10.700), However, after 180 days, households in the free-trial group were more likely to repurchase Klorfasil (86.4% to 74.8%). Fewer households in the intervention group purchased Klorfasil, but more households in the intervention group continued to purchase Klorfasil after 180 days. Our study also confirms that water treatment practices decrease over time.