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Choi WS, Roh BR, Jon DI, Ryu V, Oh Y, Hong HJ. An exploratory study on spatiotemporal clustering of suicide in Korean adolescents. Child Adolesc Psychiatry Ment Health 2024; 18:54. [PMID: 38730504 PMCID: PMC11088016 DOI: 10.1186/s13034-024-00745-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND Adolescent suicides are more likely to form clusters than those of other age groups. However, the definition of a cluster in the space-time dimension has not been established, neither are the factors contributing to it well known. Therefore, this study aimed to identify space-time clusters in adolescent suicides in Korea and to examine the differences between clustered and non-clustered cases using novel statistical methods. METHODS From 2016 to 2020, the dates and locations, including specific addresses from which the latitude and longitude of all student suicides (aged 9-18 years) in Korea were obtained through student suicide reports. Sociodemographic characteristics of the adolescents who died by suicide were collected, and the individual characteristics of each student who died by suicide were reported by teachers using the Strengths and Difficulties Questionnaire (SDQ). Density-Based Spatial Clustering of Applications with Noise (DBSCAN) analysis was used to assess the clustering of suicides. RESULTS We identified 23 clusters through the data analysis of 652 adolescent suicides using DBSCAN. By comparing the size of each cluster, we identified 63 (9.7%) spatiotemporally clustered suicides among adolescents, and the temporal range of these clusters was 7-59 days. The suicide cluster group had a lower economic status than the non-clustered group. There were no significant differences in other characteristics between the two groups. CONCLUSION This study has defined the space-time cluster of suicides using a novel statistical method. Our findings suggest that when an adolescent suicide occurs, close monitoring and intervention for approximately 2 months are needed to prevent subsequent suicides. Future research using DBSCAN needs to involve a larger sample of adolescents from various countries to further corroborate these findings.
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Affiliation(s)
- Won-Seok Choi
- Department of Psychiatry, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Beop-Rae Roh
- Department of Social Welfare, Pukyong National University, Busan, Republic of Korea
| | - Duk-In Jon
- Department of Psychiatry, Hallym University Sacred Heart Hospital, Hallym University, 22, Gwanpyeong-ro 170Beon-gil, Dongan-gu, Anyang, Gyeonggi-do, Republic of Korea
| | - Vin Ryu
- Department of Psychiatry, Hallym University Sacred Heart Hospital, Hallym University, 22, Gwanpyeong-ro 170Beon-gil, Dongan-gu, Anyang, Gyeonggi-do, Republic of Korea
| | - Yunhye Oh
- Department of Psychiatry, Hallym University Sacred Heart Hospital, Hallym University, 22, Gwanpyeong-ro 170Beon-gil, Dongan-gu, Anyang, Gyeonggi-do, Republic of Korea
| | - Hyun Ju Hong
- Department of Psychiatry, Hallym University Sacred Heart Hospital, Hallym University, 22, Gwanpyeong-ro 170Beon-gil, Dongan-gu, Anyang, Gyeonggi-do, Republic of Korea.
- Hallym University Suicide and School Mental Health Institute, Anyang, Republic of Korea.
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Lu FW, Conway E, Liang YL, Chen YY, Gunnell D, Chang SS. Space-time self-harm and suicide clusters in two cities in Taiwan. Epidemiol Psychiatr Sci 2023; 32:e37. [PMID: 37258458 DOI: 10.1017/s2045796023000513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
AIMS Suicidal acts may cluster in time and space and lead to community concerns about further imitative suicidal episodes. Although suicide clusters have been researched in previous studies, less is known about the clustering of non-fatal suicidal behaviour (self-harm). Furthermore, most previous studies used crude temporal and spatial information, e.g., numbers aggregated by month and residence area, for cluster detection analysis. This study aimed to (i) identify space-time clusters of self-harm and suicide using daily incidence data and exact address and (ii) investigate the characteristics of cluster-related suicidal acts. METHODS Data on emergency department presentations for self-harm and suicide deaths in Taipei City and New Taipei City, Taiwan, were used in this study. In all-age and age-specific analyses, self-harm and suicide clusters were identified using space-time permutation scan statistics. A cut-off of 0.10 for the p value was used to identify possible clusters. Logistic regression was used to investigate the characteristics associated with cluster-related episodes. RESULTS A total of 5,291 self-harm episodes and 1,406 suicides in Taipei City (2004-2006) and 20,531 self-harm episodes and 2,329 suicides in New Taipei City (2012-2016) were included in the analysis. In the two cities, two self-harm clusters (n [number of self-harm episodes or suicide deaths in the cluster] = 4 and 8 in Taipei City), four suicide clusters (n = 3 in Taipei City and n = 4, 11 and 4 in New Taipei City) and two self-harm and suicide combined clusters (n = 4 in Taipei City and n = 8 in New Taipei City) were identified. Space-time clusters of self-harm, suicide, and self-harm and suicide combined accounted for 0.05%, 0.59%, and 0.08% of the respective groups of suicidal acts. Cluster-related episodes of self-harm and suicide were more likely to be male (adjusted odds ratio [aOR] = 2.22, 95% confidence interval [CI] 1.26, 3.89) and young people aged 10-29 years (aOR = 2.72, 95% CI 1.43, 5.21) than their cluster-unrelated counterparts. CONCLUSIONS Space-time clusters of self-harm, suicide, and self-harm and suicide combined accounted for a relatively small proportion of suicidal acts and were associated with some sex/age characteristics. Focusing on suicide deaths alone may underestimate the size of some clusters and/or lead to some clusters being overlooked. Future research could consider combining self-harm and suicide data and use social connection information to investigate possible clusters of suicidal acts.
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Affiliation(s)
- Fang-Wen Lu
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Erica Conway
- Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
- Global Health Program, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Ya-Lun Liang
- Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Ying-Yeh Chen
- Taipei City Psychiatric Centre, Taipei City Hospital, Taipei, Taiwan
- Institute of Public Health and Department of Public Health, National Yang-Ming Chiao Tung University, Taipei, Taiwan
| | - David Gunnell
- Centre for Academic Mental Health, Population Health Sciences, University of Bristol, Bristol, UK
- National Institute of Health Research Biomedical Research Centre, University Hospitals Bristol and Weston National Health Service Foundation Trust, Bristol, UK
| | - Shu-Sen Chang
- Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
- Global Health Program, College of Public Health, National Taiwan University, Taipei, Taiwan
- Psychiatric Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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Disadvantaged by More Than Distance: A Systematic Literature Review of Injury in Rural Australia. SAFETY 2022. [DOI: 10.3390/safety8030066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Rural populations experience injury-related mortality and morbidity rates 1.5 times greater than metropolitan residents. Motivated by a call for stronger epidemiological evidence around rural injuries to inform prevention, a systematic review of peer-reviewed literature published between January 2010 and March 2021 was undertaken to explore the epidemiology of rural injury and associated risk factors in Australia. A subsequent aim was to explore definitions of rurality used in injury prevention studies. There were 151 papers included in the review, utilizing 23 unique definitions to describe rurality. People living in rural areas were more likely to be injured, for injuries to be more severe, and for injuries to have greater resulting morbidity than people in metropolitan areas. The increase in severity reflects the mechanism of rural injury, with rural injury events more likely to involve a higher energy exchange. Risk-taking behavior and alcohol consumption were significant risk factors for rural injury, along with rural cluster demographics such as age, sex, high socio-economic disadvantage, and health-related comorbidities. As injury in rural populations is multifactorial and nonhomogeneous, a wide variety of evidence-based strategies are needed. This requires funding, political leadership for policy formation and development, and implementation of evidence-based prevention interventions.
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Benson R, Rigby J, Brunsdon C, Cully G, Too LS, Arensman E. Quantitative Methods to Detect Suicide and Self-Harm Clusters: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095313. [PMID: 35564710 PMCID: PMC9099648 DOI: 10.3390/ijerph19095313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/20/2022] [Accepted: 04/23/2022] [Indexed: 11/16/2022]
Abstract
Suicide and self-harm clusters exist in various forms, including point, mass, and echo clusters. The early identification of clusters is important to mitigate contagion and allocate timely interventions. A systematic review was conducted to synthesize existing evidence of quantitative analyses of suicide and self-harm clusters. Electronic databases including Medline, Embase, Web of Science, and Scopus were searched from date of inception to December 2020 for studies that statistically analyzed the presence of suicide or self-harm clusters. Extracted data were narratively synthesized due to heterogeneity among the statistical methods applied. Of 7268 identified studies, 79 were eligible for narrative synthesis. Most studies quantitatively verified the presence of suicide and self-harm clusters based on the scale of the data and type of cluster. A Poisson-based scan statistical model was found to be effective in accurately detecting point and echo clusters. Mass clusters are typically detected by a time-series regression model, although limitations exist. Recently, the statistical analysis of suicide and self-harm clusters has progressed due to advances in quantitative methods and geospatial analytical techniques, most notably spatial scanning software. The application of such techniques to real-time surveillance data could effectively detect emerging clusters and provide timely intervention.
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Affiliation(s)
- Ruth Benson
- School of Public Health, College of Medicine and Health, University College Cork, Western Gateway Building, T12 XF62 Cork, Ireland; (G.C.); (E.A.)
- National Suicide Research Foundation, University College Cork, 4.28 Western Gateway Building, T12 XF62 Cork, Ireland
- Correspondence:
| | - Jan Rigby
- National Centre for Geocomputation, Maynooth University, W23 F2H6 Maynooth, Ireland; (J.R.); (C.B.)
| | - Christopher Brunsdon
- National Centre for Geocomputation, Maynooth University, W23 F2H6 Maynooth, Ireland; (J.R.); (C.B.)
| | - Grace Cully
- School of Public Health, College of Medicine and Health, University College Cork, Western Gateway Building, T12 XF62 Cork, Ireland; (G.C.); (E.A.)
- National Suicide Research Foundation, University College Cork, 4.28 Western Gateway Building, T12 XF62 Cork, Ireland
| | - Lay San Too
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC 3053, Australia;
| | - Ella Arensman
- School of Public Health, College of Medicine and Health, University College Cork, Western Gateway Building, T12 XF62 Cork, Ireland; (G.C.); (E.A.)
- National Suicide Research Foundation, University College Cork, 4.28 Western Gateway Building, T12 XF62 Cork, Ireland
- Australian Institute for Suicide Research and Prevention, School of Applied Psychology, Griffith University, Brisbane, QLD 4122, Australia
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Law PCF, Too LS, Hill NTM, Robinson J, Gould M, Occhipinti JA, Spittal MJ, Witt K, Sinyor M, Till B, Osgood N, Prodan A, Zahan R, Pirkis J. A Pilot Case-Control Study of the Social Media Activity Following Cluster and Non-Cluster Suicides in Australia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:343. [PMID: 35010601 PMCID: PMC8751152 DOI: 10.3390/ijerph19010343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/21/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
Social media may play a role in the "contagion" mechanism thought to underpin suicide clusters. Our pilot case-control study presented a novel methodological approach to examining whether Facebook activity following cluster and non-cluster suicides differed. We used a scan statistic to identify suicide cluster cases occurring in spatiotemporal clusters and matched each case to 10 non-cluster control suicides. We identified the Facebook accounts of 3/48 cluster cases and 20/480 non-cluster controls and their respective friends-lists and retrieved 48 posthumous posts and replies (text segments) referring to the deceased for the former and 606 for the latter. We examined text segments for "putatively harmful" and "putatively protective" content (e.g., discussion of the suicide method vs. messages discouraging suicidal acts). We also used concept mapping, word-emotion association, and sentiment analysis and gauged user reactions to posts using the reactions-to-posts ratio. We found no "putatively harmful" or "putatively protective" content following any suicides. However, "family" and "son" concepts were more common for cluster cases and "xx", "sorry" and "loss" concepts were more common for non-cluster controls, and there were twice as many surprise- and disgust-associated words for cluster cases. Posts pertaining to non-cluster controls were four times as receptive as those about cluster cases. We hope that the approach we have presented may help to guide future research to explain suicide clusters and social-media contagion.
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Affiliation(s)
- Phillip Cheuk Fung Law
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Parkville 3053, Australia; (L.S.T.); (M.J.S.); (J.P.)
| | - Lay San Too
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Parkville 3053, Australia; (L.S.T.); (M.J.S.); (J.P.)
| | - Nicole T. M. Hill
- Telethon Kids Institute, Nedlands 6009, Australia;
- School of Population and Global Health, The University of Western Australia, Nedlands 6009, Australia
| | - Jo Robinson
- Orygen, Parkville 3052, Australia; (J.R.); (K.W.)
- Centre for Youth Mental Health, The University of Melbourne, Parkville 3053, Australia
| | - Madelyn Gould
- Departments of Epidemiology and Psychiatry, Columbia University, New York, NY 10032, USA;
| | - Jo-An Occhipinti
- Brain and Mind Centre, Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia; (J.-A.O.); (A.P.)
- Computer Simulation and Advanced Research Technologies (CSART), Sydney 2021, Australia
| | - Matthew J. Spittal
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Parkville 3053, Australia; (L.S.T.); (M.J.S.); (J.P.)
| | - Katrina Witt
- Orygen, Parkville 3052, Australia; (J.R.); (K.W.)
- Centre for Youth Mental Health, The University of Melbourne, Parkville 3053, Australia
| | - Mark Sinyor
- Sunnybrook Health Sciences Centre, Department of Psychiatry, University of Toronto, Toronto, ON M4N 3M5, Canada;
| | - Benedikt Till
- Unit Suicide Research & Mental Health Promotion, Department of Social and Preventive Medicine, Center for Public Health, Medical University of Vienna, 1090 Vienna, Austria;
| | - Nathaniel Osgood
- Department of Computer Science, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada; (N.O.); (R.Z.)
| | - Ante Prodan
- Brain and Mind Centre, Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia; (J.-A.O.); (A.P.)
- Translational Health Research Institute, Western Sydney University, Penrith 2751, Australia
| | - Rifat Zahan
- Department of Computer Science, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada; (N.O.); (R.Z.)
| | - Jane Pirkis
- Centre for Mental Health, Melbourne School of Population and Global Health, The University of Melbourne, Parkville 3053, Australia; (L.S.T.); (M.J.S.); (J.P.)
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Torok M, Konings P, Passioura J, Chen NA, Hewett M, Phillips M, Burnett A, Shand F, Christensen H. Spatial Errors in Automated Geocoding of Incident Locations in Australian Suicide Mortality Data. Epidemiology 2021; 32:896-903. [PMID: 34310446 DOI: 10.1097/ede.0000000000001403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND There is increasing interest in the spatial analysis of suicide data to identify high-risk (often public) locations likely to benefit from access restriction measures. The identification of such locations, however, relies on accurately geocoded data. This study aims to examine the extent to which common completeness and positional spatial errors are present in suicide data due to the underlying geocoding process. METHODS Using Australian suicide mortality data from the National Coronial Information System for the period of 2008-2017, we compared the custodian automated geocoding process to an alternate multiphase process. Descriptive and kernel density cluster analyses were conducted to ascertain data completeness (address matching rates) and positional accuracy (distance revised) differences between the two datasets. RESULTS The alternate geocoding process initially improved address matching from 67.8% in the custodian dataset to 78.4%. Additional manual identification of nonaddress features (such as cliffs or bridges) improved overall match rates to 94.6%. Nearly half (49.2%) of nonresidential suicide locations were revised more than 1,000 m from data custodian coordinates. Spatial misattribution rates were greatest at the smallest levels of geography. Kernel density maps showed clear misidentification of hotspots relying solely on autogeocoded data. CONCLUSION Suicide incidents that occur at nonresidential addresses are being erroneously geocoded to centralized fall-back locations in autogeocoding processes, which can lead to misidentification of suicide clusters. Our findings provide insights toward defining the nature of the problem and refining geocoding processes, so that suicide data can be used reliably for the detection of suicide hotspots. See video abstract at, http://links.lww.com/EDE/B862.
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Affiliation(s)
- Michelle Torok
- From the Black Dog Institute, University of New South Wales, Sydney, NSW, Australia
| | - Paul Konings
- National Centre for Geographic Resources & Analysis in Primary Health Care, Research School of Population Health, Australian National University, Canberra, Australia
| | - Jason Passioura
- National Centre for Geographic Resources & Analysis in Primary Health Care, Research School of Population Health, Australian National University, Canberra, Australia
| | - Nicole A Chen
- Orygen Youth Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Michael Hewett
- National Centre for Geographic Resources & Analysis in Primary Health Care, Research School of Population Health, Australian National University, Canberra, Australia
| | - Matthew Phillips
- From the Black Dog Institute, University of New South Wales, Sydney, NSW, Australia
| | - Alexander Burnett
- From the Black Dog Institute, University of New South Wales, Sydney, NSW, Australia
| | - Fiona Shand
- From the Black Dog Institute, University of New South Wales, Sydney, NSW, Australia
| | - Helen Christensen
- From the Black Dog Institute, University of New South Wales, Sydney, NSW, Australia
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