Open Access Open Badges Research article

Self-poisoning in rural Sri Lanka: small-area variations in incidence

Celie Manuel13*, David J Gunnell2, Wim van der Hoek1, Andrew Dawson345, Ishika K Wijeratne6 and Flemming Konradsen13

Author Affiliations

1 Department of International Health, Institute of International health, Immunology and Microbiology, University of Copenhagen, Øster Farimagsgade 5, Building 16, P.O. Box 2099, 1014 Cph K, Denmark

2 Department of Social Medicine, University of Bristol, Bristol, UK

3 South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Sri Lanka

4 Department of Clinical Medicine, University of Peradeniya, Sri Lanka

5 School of Population Health, University of Newcastle, Australia

6 Urban Development Authority, GIS Centre, "Sethsiripaya", Battaramulla, Sri Lanka

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BMC Public Health 2008, 8:26  doi:10.1186/1471-2458-8-26

Published: 23 January 2008



Self-poisoning is one of the most common methods of suicide worldwide. The intentional ingestion of pesticides is the main contributor to such deaths and in many parts of rural Asia pesticide self-poisoning is a major public health problem. To inform the development of preventive measures in these settings, this study investigates small-area variation in self-poisoning incidence and its association with area-based socioeconomic and agricultural factors.


Ecological analysis of intentional self-poisoning in a rural area (population 267,613) of Sri Lanka in 2002. The geographic distribution of cases was mapped to place of residence. Using administrative division (GN), median population size 1416, as unit of analysis, associations with socioeconomic and agricultural indicators were explored using negative binomial regression models.


The overall incidence of intentional self-poisoning in the study area was 315 per 100,000 (range: 0 – 2168 per 100,000 across GNs). Socioeconomic disadvantage, as indexed by poor housing quality (p = 0.003) and low levels of education (p < 0.001) but not unemployment (p = 0.147), was associated with a low self-poisoning incidence. Areas where a high proportion of the population worked in agriculture had low overall levels of self-poisoning (p = 0.002), but a greater proportion of episodes in these areas involved pesticides (p = 0.01). An association with extent of cultivated land was found only for non-pesticide poisoning (p = 0.01).


Considerable small-area variation in incidence rates of intentional self-poisoning was found. The noteworthy concentration of cases in certain areas and the inverse association with socioeconomic deprivation merit attention and should be investigated using individual-level exposure data.