Condition category
Infections and Infestations
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

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,

Trial website

Contact information



Primary contact

Prof Feng-jen Tsai


Contact details

250 Wu-Hsing Street
Taipei City

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Does a free-trial approach increase purchase and use of a water purification product in rural Haiti? A cluster randomized control trial.


Study hypothesis

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

Ethics approval

Taipei Medical University Joint Institutional Review Board, 20/04/2016, TMU IJIRB No. N201603084

Study design

Single-blinded cluster randomized control trial

Primary study design


Secondary study design

Cluster randomised trial

Trial setting


Trial type


Patient information sheet

See additional files


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.

Intervention type



Drug names

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)

Participant type

Healthy volunteer

Age group




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

Sponsor information


Taipei Medical University

Sponsor details

250 Wu-Hsing Street
Taipei City

Sponsor type




Funder type

Not defined

Funder name

investigator initiated and funded

Alternative name(s)

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)

Publication list

Publication citations

Additional files

Editorial Notes

07/11/2019: Internal review. 02/04/2019: The participant information sheet has been uploaded.