Estimation of the rate and number of underreported deliberate self-poisoning attempts in western Iran in 2015.

OBJECTIVES: Rates of attempted deliberate self-poisoning (DSP) are subject to undercounting, underreporting, and denial of the suicide attempt. In this study, we estimated the rate of underreported DSP, which is the most common method of attempted suicide in Iran.

METHODS: We estimated the rate and number of unaccounted individuals who attempted DSP in western Iran in 2015 using a truncated count model. In this method, the number of people who attempted DSP but were not referred to any health care centers, n0, was calculated through integrating hospital and forensic data. The crude and age-adjusted rates of attempted DSP were estimated directly using the average population size of the city of Kermanshah and the World Health Organization (WHO) world standard population with and without accounting for underreporting. The Monte Carlo method was used to determine the confidence level.

RESULTS: The recorded number of people who attempted DSP was estimated by different methods to be in the range of 46.6 to 53.2% of the actual number of individuals who attempted DSP. The rate of underreported cases was higher among women than men and decreased as age increased. The rate of underreported cases decreased as the potency and intensity of toxic factors increased. The highest underreporting rates of 69.9, 51.2, and 21.5% were observed when oil and detergents (International Classification of Diseases, 10th revision [ICD-10] code: X66), medications (ICD-10 code: X60-X64), and agricultural toxins (ICD-10 codes: X68, X69) were used for poisoning, respectively. Crude rates, with and without accounting for underreporting, were estimated by the mixture method as 167.5 per 100,000 persons and 331.7 per 100,000 persons, respectively, which decreased to 129.8 per 100,000 persons and 253.1 per 100,000 persons after adjusting for age on the basis of the WHO world standard population.

CONCLUSIONS: Nearly half of individuals who attempted DSP were not referred to a hospital for treatment or denied the suicide attempt for political or sociocultural reasons. Individuals with no access to counseling services are at a higher risk for repeated suicide attempts and fatal suicides.