Gatekeeper training for vendors to reduce pesticide self-poisoning in rural South Asia: a study protocol for a stepped-wedge cluster randomised controlled trial.

INTRODUCTION: Pesticide self-poisoning kills an estimated 110 000-168 000 people worldwide annually. Data from South Asia indicate that in 15%-20% of attempted suicides and 30%-50% of completed suicides involving pesticides these are purchased shortly beforehand for this purpose. Individuals who are intoxicated with alcohol and/or non-farmers represent 72% of such customers. We have developed a 'gatekeeper' training programme for vendors to enable them to identify individuals at high risk of self-poisoning (gatekeeper function) and prevent such individuals from accessing pesticides (means restriction). The primary aim of the study is to evaluate the effectiveness of the gatekeeper intervention in preventing pesticide self-poisoning in Sri Lanka. Other aims are to identify method substitution and to assess the cost and cost-effectiveness of the intervention. METHODS AND ANALYSIS: A stepped-wedge cluster randomised trial of a gatekeeper intervention is being conducted in rural Sri Lanka with a population of approximately 2.7 million. The gatekeeper intervention is being introduced into 70 administrative divisions in random order at each of 30 steps over a 40-month period. The primary outcome is the number of pesticide self-poisoning cases identified from surveillance of hospitals and police stations. Secondary outcomes include: number of self-poisoning cases using pesticides purchased within the previous 24 hours, total number of all forms of self-harm and suicides. Intervention effectiveness will be estimated by comparing outcome measures between the pretraining and post-training periods across the divisions in the study area. The original study protocol has been adapted as necessary in light of the impact of the COVID-19. ETHICS AND DISSEMINATION: The Ethical Review Committee of the Faculty of Medicine and Allied Sciences, Rajarata University, Sri Lanka (ERC/2018/30), and the ACCORD Medical Research Ethics Committee, Edinburgh University (18-HV-053) approved the study. Results will be disseminated in scientific peer-reviewed journals. TRIAL REGISTRATION NUMBER: SLCTR/2019/006, U1111-1220-8046.

Using ex-ante economic evaluation to inform research priorities in pesticide self-poisoning prevention: the case of a shop-based gatekeeper training programme in rural Sri Lanka.

OBJECTIVES: Suicide by pesticide self-poisoning is a major public health challenge in low- and middle-income countries. While effectiveness studies are required to test alternative prevention approaches, economic evidence is lacking to inform decision-making in research priority setting. Therefore, this study aimed to estimate the costs of a shop-based gatekeeper training programme for pesticide vendors seeking to prevent pesticide self-poisoning in rural Sri Lanka and assess its potential for cost-effectiveness. METHODS: Ex-ante cost and cost-effectiveness threshold (CET) analyses were performed from a governmental perspective based on a three-year analytic horizon, using 'no programme' as a comparator. A programme model targeting all 535 pesticide shops in the North Central Province and border areas was applied. Total programme costs (TPC) were estimated in 2019 USD using an ingredients approach and 3% annual discounting. The Sri Lankan gross domestic product per capita and life years saved were used as CET and effectiveness measure, respectively. Sensitivity analyses were performed. RESULTS: TPC were estimated at 31 603.03 USD. TPC were sensitive to cost changes of training material and equipment and the programme lifetime. The programme needs to prevent an estimated 0.23 fatal pesticide self-poisoning cases over three years to be considered cost-effective. In the sensitivity analyses, the highest number of fatal cases needed to be prevented to obtain cost-effectiveness was 4.55 over three years. CONCLUSIONS: From an economic perspective, the programme has a very high potential to be cost-effective. Research assessing its effectiveness should therefore be completed, and research analysing its transferability to other settings prioritised.

OBJECTIFS: Le suicide par auto-intoxication par les pesticides est un défi majeur de santé publique dans les pays à revenu faible ou intermédiaire. Bien que des études d'efficacité soient nécessaires pour tester d'autres approches de prévention, les données économiques manquent pour informer la prise de décision dans les priorités de recherche. Par conséquent, cette étude visait à estimer les coûts d'un programme de formation des vendeurs dans les magasins de pesticides visant à prévenir l'auto-intoxication par les pesticides dans les régions rurales du Sri Lanka et à évaluer son potentiel de rentabilité. MÉTHODES: Les analyses ex-ante des coûts et des seuils de rentabilité (SR) ont été réalisées dans une perspective gouvernementale sur la base d'un horizon analytique de trois ans, en utilisant «l'absence de programme¼ comme comparateur. Un modèle de programme ciblant les 535 magasins de pesticides de la province du Centre-Nord et des zones frontalières a été appliqué. Les coûts totaux du programme (CTP) ont été estimés en USD 2019 en utilisant une approche d'ingrédients et une remise annuelle de 3%. Le produit intérieur brut sri-lankais par habitant et les années de vie sauvées ont été utilisés comme SR et mesure d'efficacité, respectivement. Des analyses de sensibilité ont été effectuées. RÉSULTATS: le CTP a été estimé à 31.603,03 USD. Le CTP était sensible aux changements de coût du matériel et de l'équipement de formation et de la durée de vie du programme. Le programme devrait prévenir environ 0,23 cas d'auto-intoxication mortelle par des pesticide sur trois ans pour être considéré comme rentable. Dans les analyses de sensibilité, le plus grand nombre de cas mortels à prévenir pour obtenir une rentabilité était de 4,55 sur trois ans. CONCLUSIONS: D'un point de vue économique, le programme a un potentiel très élevé pour être rentable. La recherche évaluant son efficacité doit donc être complétée et la recherche analysant sa transférabilité à d'autres contextes doit être priorisée.

Cost-effectiveness analyses of self-harm strategies aimed at reducing the mortality of pesticide self-poisonings in Sri Lanka: a study protocol.

INTRODUCTION: An estimated 803,900 people worldwide died as a result of self-harm in 2012. The deliberate ingestion of pesticides has been identified as the method most frequently used to commit fatal self-harm globally. In Sri Lanka, it is estimated that up to 60% of all suicides are committed using this method. The aim of the present study is to assess the cost-effectiveness of an ongoing safe storage intervention currently taking place in a rural Sri Lankan district and to model the cost-effectiveness of implementing the safe storage intervention as well as four potential interventions (legislative, medical management, follow-up contact and mobile phone contact) on a national level. METHODS AND ANALYSIS: Study design for all the strategies is a cost-effectiveness analysis. A governmental perspective is adopted. The time horizon for tracking the associated costs and health outcomes of the safe storage intervention on district level runs over 3 years. The time horizon is extended to 5 years when modelling a full national roll-out of the respective interventions. The discounting of costs and health outcomes are undertaken at the recommended real rate of 3%. Threshold analyses of the modelled strategies are employed to assess the strategies potential for cost-effectiveness, running scenarios with health outcome improvements ranging from 1% to 100%. Sensitivity analyses are also performed. The main outcome measures of the safe storage intervention are incremental cost-effectiveness ratios. ETHICS AND DISSEMINATION: Ethical approval was granted for the safe storage project from the University of Peradeniya, Sri Lanka, in March of 2008. An amendment for the present study was granted from Rajarata University of Sri Lanka in November of 2013. Findings will be disseminated to public and private stakeholders in local and national government in Sri Lanka as well as the wider academic audience through peer-reviewed publications and international conferences. TRIAL REGISTRATION NUMBER: The safe storage cluster trial is registered with the Clinical Trials, ref: NCT1146496 (http://clinicaltrialsfeeds.org/clinical-trials/show/NCT1146496).