Trends in solids/liquids poisoning suicide rates in Taiwan: a test of the substitution hypothesis

Examining the Spread of Charcoal-Burning Suicide in Taiwan

Background: Charcoal-burning has become a predominant method of suicide in many East-Asian countries since the 1990s. Aims: To explore charcoal-burning suicide trends from 1996 to 2020 in Taiwan. Methods: Joinpoint regression models were applied to identify suicide trends over the study period. Decompositional analyses quantified the contributions of age, sex, suicide method, and area of residence to suicide rate trends, accounting for age and geographical distribution of the general population, with a focus on charcoal-burning suicide. Results: There were three stages of suicide rate trends: increasing (1996-2006), descending (2006-2011), and levelling-off (2011-2020). Suicide by charcoal-burning accounted for 70% of the increasing suicide rates between 1996 and 2006 and 50% of the decreasing rates in the descending stage (2011-2020). During the levelling-off stage, suicide by charcoal-burning continued to decrease, albeit slowly. During the descending stage, there was a partial "substitution" of jumping for charcoal-burning. During the levelling-off stage, suicide by hanging partially "substituted" for suicide by charcoal-burning. Limitations: The variables included were limited by data availability. Conclusions: Charcoal-burning remains the second most common method of suicide in Taiwan today. Charcoal-burning has been partially replaced in the last 10 years by jumping and hanging. Monitoring suicide methods and trends is essential for suicide prevention interventions.

Association Between Means Restriction of Poison and Method-Specific Suicide Rates

Question

Findings

Meaning

Importance

Objective

Evidence Review

Findings

Conclusions and Relevance

Machine learning methods for developing precision treatment rules with observational data

Clinical trials have identified a variety of predictor variables for use in precision treatment protocols, ranging from clinical biomarkers and symptom profiles to self-report measures of various sorts. Although such variables are informative collectively, none has proven sufficiently powerful to guide optimal treatment selection individually. This has prompted growing interest in the development of composite precision treatment rules (PTRs) that are constructed by combining information across a range of predictors. But this work has been hampered by the generally small samples in randomized clinical trials and the use of suboptimal analysis methods to analyze the resulting data. In this paper, we propose to address the sample size problem by: working with large observational electronic medical record databases rather than controlled clinical trials to develop preliminary PTRs; validating these preliminary PTRs in subsequent pragmatic trials; and using ensemble machine learning methods rather than individual algorithms to carry out statistical analyses to develop the PTRs. The major challenges in this proposed approach are that treatment are not randomly assigned in observational databases and that these databases often lack measures of key prescriptive predictors and mental disorder treatment outcomes. We proposed a tiered case-cohort design approach that uses innovative methods for measuring and balancing baseline covariates and estimating PTRs to address these challenges.

Prevention of suicide with regulations aimed at restricting access to highly hazardous pesticides: a systematic review of the international evidence

BACKGROUND

Pesticide self-poisoning accounts for 14-20% of suicides worldwide. Regulation aimed at restricting access to pesticides or banning highly hazardous pesticides is one approach to reducing these deaths. We systematically reviewed the evidence of the effectiveness of pesticide regulation in reducing the incidence of pesticide suicides and overall suicides.

METHODS

We did a systematic review of the international evidence. We searched MEDLINE, PsycINFO, and Embase for studies published between Jan 1, 1960, and Dec 31, 2016, which investigated the effect of national or regional bans, and sales or import restrictions, on the availability of one or more pesticides and the incidence of suicide in different countries. We excluded other interventions aimed at limiting community access to pesticides. We extracted data from studies presenting pesticide suicide data and overall suicide data from before and after national sales restrictions. Two reviewers independently assessed papers for inclusion, extracted data, and assessed risk of bias. We undertook a narrative synthesis of the data in each report, and where data were available for the years before and after a ban, we pooled data for the 3 years before and the 3 years after to obtain a crude estimate of the effect of the ban. This study is registered through PROSPERO, number CRD42017053329.

FINDINGS

We identified 27 studies undertaken in 16 countries-five low-income or middle-income countries (Bangladesh, Colombia, India, Jordan and Sri Lanka), and 11 high-income countries (Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, South Korea, Taiwan, UK, and USA). Assessments largely focused on national bans of specific pesticides (12 studies of bans in six countries-Jordan, Sri Lanka, Bangladesh, Greece [Crete], South Korea, and Taiwan) or sales restrictions (eight studies of restrictions in five countries- India, Denmark, Ireland, the UK and the USA). Only five studies used optimum analytical methods. National bans on commonly ingested pesticides in five of the six countries studied, including four studies using optimum analytical methods, were followed by reductions in pesticide suicides and, in three of these countries, falls in overall suicide mortality. Greece was the only country studied that did not show a decrease in pesticide suicide following a ban. There were no high-quality studies of restricting sales to people for occupational uses; four of the seven studies (in three of the five countries studied-India, Denmark, and the USA) showed sales restrictions were followed by decreases in pesticide suicides; one of the two studies investigating trends in overall suicide mortality reported a fall in deaths in Denmark, but there were also decreases in suicide deaths from other methods.

INTERPRETATION

National bans on highly hazardous pesticides, which are commonly ingested in acts of self-poisoning, seem to be effective in reducing pesticide-specific and overall suicide rates. Evidence is less consistent for sales restrictions. A worldwide ban on the use of highly hazardous pesticides is likely to prevent tens of thousands of deaths every year.

FUNDING

None.

Characteristics of suicidal attempts among farmers in rural South India

BACKGROUND

Globally, farming as an industry is considered a high-risk occupation for suicides. Certain states in India like Karnataka have a suicide rate higher than the national average, and this is generally attributed to the farmers' suicide.

AIMS

The aim is to study the characteristics of suicidal attempts among the farmer community in South India, with special emphasis on gender differences, modes used, and the immediate precipitant causes.

MATERIALS AND METHODS

Retrospective, case register-based, explorative-descriptive study of 426 consecutive medicolegal case files of patients whose stated occupation was farming and who were admitted as cases of deliberate self-harm or suicide attempt to a rural tertiary care hospital in rural South India.

RESULTS

Out of the 426 farmers who attempted suicide, majority were male (355, 83.3%), in the age group of 21-40 years (318, 75%), married (358, 84%), and belonging to lower socioeconomic status (268, 62.9%). About 54% of them had attempted suicide by consuming pesticides (230). Surprisingly, 183 (43%) and 86 (20.2%) reported the immediate precipitant as being relationship issues and marital conflict, respectively, and only 100 (23.5%) attributed it to financial reasons. Females were significantly associated with a past history of suicidal attempt while males tended to abuse alcohol before an attempt more frequently.

CONCLUSIONS

Pesticide poisoning was the most common mode for attempting suicide among the farmers. Contrary to public perception and other studies, relationship, and marital issues, not financial reasons were found to be the most common immediate precipitant for the attempters in our study.

Suicide prevention strategies revisited: 10-year systematic review

BACKGROUND

Many countries are developing suicide prevention strategies for which up-to-date, high-quality evidence is required. We present updated evidence for the effectiveness of suicide prevention interventions since 2005.

METHODS

We searched PubMed and the Cochrane Library using multiple terms related to suicide prevention for studies published between Jan 1, 2005, and Dec 31, 2014. We assessed seven interventions: public and physician education, media strategies, screening, restricting access to suicide means, treatments, and internet or hotline support. Data were extracted on primary outcomes of interest, namely suicidal behaviour (suicide, attempt, or ideation), and intermediate or secondary outcomes (treatment-seeking, identification of at-risk individuals, antidepressant prescription or use rates, or referrals). 18 suicide prevention experts from 13 European countries reviewed all articles and rated the strength of evidence using the Oxford criteria. Because the heterogeneity of populations and methodology did not permit formal meta-analysis, we present a narrative analysis.

FINDINGS

We identified 1797 studies, including 23 systematic reviews, 12 meta-analyses, 40 randomised controlled trials (RCTs), 67 cohort trials, and 22 ecological or population-based investigations. Evidence for restricting access to lethal means in prevention of suicide has strengthened since 2005, especially with regard to control of analgesics (overall decrease of 43% since 2005) and hot-spots for suicide by jumping (reduction of 86% since 2005, 79% to 91%). School-based awareness programmes have been shown to reduce suicide attempts (odds ratio [OR] 0·45, 95% CI 0·24-0·85; p=0·014) and suicidal ideation (0·5, 0·27-0·92; p=0·025). The anti-suicidal effects of clozapine and lithium have been substantiated, but might be less specific than previously thought. Effective pharmacological and psychological treatments of depression are important in prevention. Insufficient evidence exists to assess the possible benefits for suicide prevention of screening in primary care, in general public education and media guidelines. Other approaches that need further investigation include gatekeeper training, education of physicians, and internet and helpline support. The paucity of RCTs is a major limitation in the evaluation of preventive interventions.

INTERPRETATION

In the quest for effective suicide prevention initiatives, no single strategy clearly stands above the others. Combinations of evidence-based strategies at the individual level and the population level should be assessed with robust research designs.

FUNDING

The Expert Platform on Mental Health, Focus on Depression, and the European College of Neuropsychopharmacology.

A central storage facility to reduce pesticide suicides--a feasibility study from India

Background

Pesticide suicides are considered the single most important means of suicide worldwide. Centralized pesticide storage facilities have the possible advantage of delaying access to pesticides thereby reducing suicides. We undertook this study to examine the feasibility and acceptability of a centralized pesticide storage facility as a preventive intervention strategy in reducing pesticide suicides.

Methods

A community randomized controlled feasibility study using a mixed methods approach involving a household survey; focus group discussions (FGDs) and surveillance were undertaken. The study was carried out in a district in southern India. Eight villages that engaged in floriculture were identified. Using the lottery method two were randomized to be the intervention sites and two villages constituted the control site. Two centralized storage facilities were constructed with local involvement and lockable storage boxes were constructed. The household survey conducted at baseline and one and a half years later documented information on sociodemographic data, pesticide usage, storage and suicides.

Results

At baseline 4446 individuals (1097 households) in the intervention and 3307 individuals (782 households) in the control sites were recruited while at follow up there were 4308 individuals (1063 households) in the intervention and 2673 individuals (632 households) in the control sites. There were differences in baseline characteristics and imbalances in the prevalence of suicides between intervention and control sites as this was a small feasibility study.

The results from the FGDs revealed that most participants found the storage facility to be both useful and acceptable. In addition to protecting against wastage, they felt that it had also helped prevent pesticide suicides as the pesticides stored here were not as easily and readily accessible. The primary analyses were done on an Intention to Treat basis. Following the intervention, the differences between sites in changes in combined, completed and attempted suicide rates per 100,000 person-years were 295 (95% CI: 154.7, 434.8; p < 0.001) for pesticide suicide and 339 (95% CI: 165.3, 513.2, p < 0.001) for suicide of all methods.

Conclusions

Suicide by pesticides poisoning is a major public health problem and needs innovative interventions to address it. This study, the first of its kind in the world, examined the feasibility of a central storage facility as a means of limiting access to pesticides and, has provided preliminary results on its usefulness. These results need to be interpreted with caution in view of the imbalances between sites. The facility was found to be acceptable, thereby underscoring the need for larger studies for a longer duration.

Trial registration

ISRCTN: ISRCTN04912407

A test of the substitution hypothesis: an analysis of urban and rural trends in solid/liquid poisoning suicides in Taiwan

Taiwan experienced both a significant decrease and a significant increase in the suicide rate during the period 1986-1999, which provides a unique opportunity to examine the substitution hypothesis in suicide research: that is, whether a reduction in the use of a certain method of suicide would be offset by a parallel increase in the use of other methods. We also explored whether such method substitution, if it existed, differed across urban and rural settings. Data on age-, sex-, method-, and urban-/rural-specific suicide rates for the period 1986-1999 in Taiwan were obtained and the year of 1993 is found to be the inflection point. We analyzed using Poisson regression to estimate the average annual percentage change (AAPC) for periods of decline (1986-1993) and increase (1993-1999) in suicides. The rapid decline in suicide by solid/liquid poisoning (mostly using pesticides) during a period of accelerated economic development (1986-1999) in Taiwan was found to be associated with the increased use of alternative methods. An interaction model found a marked decrease in solid/liquid poisoning suicide in both urban and rural Taiwan over the period of decline (1986-1993). The extent of the decrease was greater in rural areas but was accompanied by a rise in the use of several other suicide methods. However, the net effect was still a marked reduction in the suicide rate. A general increase in suicide among all age groups, for all methods, in both rural and urban settings, and for both sexes was found during the period when the suicide rate increased (1993-1999). We conclude that restricting access to the means of pesticide suicides reduces not only the method-specific suicide rate but also the overall suicide rate; nonetheless, suicide method substitution is not an all-or-nothing phenomenon. Stratified analyses by geographical (i.e. urban/rural) area can help to disentangle the patterns in each subgroup, which will improve our understanding of the phenomenon and make suicide prevention efforts more focused and effective.