Effectiveness of household lockable pesticide storage to reduce pesticide self-poisoning in rural Asia: a community-based, cluster-randomised controlled trial

Abstract

SummaryBackgroundAgricultural pesticide self-poisoning is a major public health problem in rural Asia. The use of safer household pesticide storage has been promoted to prevent deaths, but there is no evidence of effectiveness. We aimed to test the effectiveness of lockable household containers for prevention of pesticide self-poisoning.MethodsWe did a community-based, cluster-randomised controlled trial in a rural area of North Central Province, Sri Lanka. Clusters of households were randomly assigned (1:1), with a sequence computer-generated by a minimisation process, to intervention or usual practice (control) groups. Intervention households that had farmed or had used or stored pesticide in the preceding agricultural season were given a lockable storage container. Further promotion of use of the containers was restricted to community posters and 6-monthly reminders during routine community meetings. The primary outcome was incidence of pesticide self-poisoning in people aged 14 years or older during 3 years of follow-up. Identification of outcome events was done by staff who were unaware of group allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT1146496.FindingsBetween Dec 31, 2010, and Feb 2, 2013, we randomly assigned 90 rural villages to the intervention group and 90 to the control group. 27 091 households (114 168 individuals) in the intervention group and 26 291 households (109 693 individuals) in the control group consented to participate. 20 457 household pesticide storage containers were distributed. In individuals aged 14 years or older, 611 cases of pesticide self-poisoning had occurred by 3 years in the intervention group compared with 641 cases in the control group; incidence of pesticide self-poisoning did not differ between groups (293·3 per 100 000 person-years of follow-up in the intervention group vs 318·0 per 100 000 in the control group; rate ratio [RR] 0·93, 95% CI 0·80–1·08; p=0·33). We found no evidence of switching from pesticide self-poisoning to other forms of self-harm, with no significant difference in the number of fatal (82 in the intervention group vs 67 in the control group; RR 1·22, 0·88–1·68]) or non-fatal (1135 vs 1153; RR 0·97, 0·86–1·08) self-harm events involving all methods.InterpretationWe found no evidence that means reduction through improved household pesticide storage reduces pesticide self-poisoning. Other approaches, particularly removal of highly hazardous pesticides from agricultural practice, are likely to be more effective for suicide prevention in rural Asia.FundingWellcome Trust, with additional support from the American Foundation for Suicide Prevention, Lister Institute of Preventive Medicine, Chief Scientist Office of Scotland, University of Copenhagen, and NHMRC Australia.

Outcomes of Community‐Based Suicide Prevention Approaches That Involve Reducing Access to Pesticides: A Systematic Literature Review

“…This left us with five eligible studies for inclusion in the review. Table provides an overview of these five studies (Eddleston et al., ; Nandi et al., ; Pearson et al., ; Vijayakumar & Satheesh‐Babu, ; Vijayakumar et al., ).…”

“…The five studies were conducted in southern Asia, three in India (Nandi et al., ; Vijayakumar & Satheesh‐Babu, ; Vijayakumar et al., ) and two in Sri Lanka (Eddleston et al., ; Pearson et al., ). All five took place in communities defined by districts or villages with a heavy dependence on agriculture that had sizeable numbers of community residents (ranging from 5,500 to 1,000,000).…”

“…Central storage facilities were accessible to key‐holding farmers in participating intervention villages between the hours of 7 a.m. and 7 p.m. (Vijayakumar et al., ). The third study examined the effectiveness of household‐based lockable pesticide storage containers, which were typically installed within the home compound, partially buried within the ground, and locked by household members (Pearson et al., ). The fourth study piloted a selective ban of two insecticides classified as Class II—or “moderately hazardous”—by the World Health Organization (Eddleston et al., ), while the fifth study piloted a selective ban of one highly toxic insecticide (Nandi et al., ).…”

“…Two studies involved cluster randomized controlled trials (Pearson et al., ; Vijayakumar et al., ), two studies employed quasi‐experimental designs (Eddleston et al., ; Vijayakumar & Satheesh‐Babu, ), and one study involved a before‐and‐after design (Nandi et al., ). In each case, the intervention was delivered in certain villages or districts, and comparisons were made with control districts or villages that were randomly or purposively selected, except for one study, which involved pre‐/postcomparisons within the same subdistrict, without a control group (Nandi et al., ).…”

“…One cluster randomized controlled trial examined changes in the rates of suicides and attempted suicides (gleaned from official records and pre‐/posthousehold surveys) in intervention and control villages following the establishment of the central storage facilities in each of the intervention villages (Vijayakumar et al., ). The other cluster randomized controlled trial examined differences in the incidence of self‐poisoning by pesticides and all substances (gleaned from hospital records, pre‐/posthousehold surveys, and official records) between intervention and control villages following the installation of household‐based storage containers (Pearson et al., ). One quasi‐experimental study compared changes in the number of suicides (ascertained from official records and interviews with community members) between intervention and control villages after the introduction of nonpesticide management in the intervention villages (Vijayakumar & Satheesh‐Babu, ).…”