Open Access Study protocol

A community-based cluster randomised trial of safe storage to reduce pesticide self-poisoning in rural Sri Lanka: study protocol

Melissa Pearson14*, Flemming Konradsen24, David Gunnell34, Andrew H Dawson45, Ravi Pieris4, Manjula Weerasinghe4, Duleeka W Knipe4, Shaluka Jayamanne46, Chris Metcalfe3, Keith Hawton7, A Rajitha Wickramasinghe5, W Atapattu8, Palitha Bandara8, Dhammika de Silva8, Asanga Ranasinghe8, Fahim Mohamed49, Nicholas A Buckley104, Indika Gawarammana114 and Michael Eddleston14

Author Affiliations

1 Clinical Pharmacology Unit, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK

2 Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark

3 School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, UK

4 South Asian Clinical Toxicology Research Collaboration (SACTRC), Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka

5 Drug Health, Royal Prince Alfred Hospital, Sydney, Australia

6 Faculty of Medicine, University of Kelanyia, Kelanyia, Sri Lanka

7 Centre for Suicide Research, Department of Psychiatry, University of Oxford, Oxford, UK

8 Provincial Department of Health Services, North Central Province, Anuradhapura, Sri Lanka

9 Department of Pharmacy, Faculty of Allied Health Sciences, University of Peradeniya, Peradeniya, Sri Lanka

10 Professorial Medicine Unit, POW Clinical School, University of New South Wales, Sydney, Australia

11 Department of Medicine, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka

For all author emails, please log on.

BMC Public Health 2011, 11:879  doi:10.1186/1471-2458-11-879

Published: 21 November 2011

Abstract

Background

The WHO recognises pesticide poisoning to be the single most important means of suicide globally. Pesticide self-poisoning is a major public health and clinical problem in rural Asia, where it has led to case fatality ratios 20-30 times higher than self-poisoning in the developed world. One approach to reducing access to pesticides is for households to store pesticides in lockable "safe-storage" containers. However, before this approach can be promoted, evidence is required on its effectiveness and safety.

Methods/Design

A community-based cluster randomised controlled trial has been set up in 44,000 households in the North Central Province, Sri Lanka. A census is being performed, collecting baseline demographic data, socio-economic status, pesticide usage, self-harm and alcohol. Participating villages are then randomised and eligible households in the intervention arm given a lockable safe storage container for agrochemicals.

The primary outcome will be incidence of pesticide self-poisoning over three years amongst individuals aged 14 years and over. 217,944 person years of follow-up are required in each arm to detect a 33% reduction in pesticide self-poisoning with 80% power at the 5% significance level. Secondary outcomes will include the incidence of all pesticide poisoning and total self-harm.

Discussion

This paper describes a large effectiveness study of a community intervention to reduce the burden of intentional poisoning in rural Sri Lanka. The study builds on a strong partnership between provincial health services, local and international researchers, and local communities. We discuss issues in relation to randomisation and contamination, engaging control villages, the intervention, and strategies to improve adherence.

Trial Registritation

The trial is registered on ClinicalTrials.gov ref: NCT1146496 (http://clinicaltrialsfeeds.org/clinical-trials/show/NCT01146496 webcite).