Variation in rates of self-harm hospital admission and re-admission by ethnicity in London: a population cohort study

C Polling,S L Hatch,I Bakolis,M Hotopf

doi:10.1007/s00127-021-02087-9

Abstract

PurposeTo compare sex-specific rates of hospital admission and repeat admission following self-harm between ethnic groups in London and test whether differences persist after adjustment for socio-economic deprivation.MethodsA population-based cohort of all individuals aged over 11 admitted to a general hospital for physical health treatment following self-harm between 2008 and 2018, using administrative Hospital Episode Statistics for all people living in Greater London.ResultsThere were 59,510 individuals admitted to the hospital following self-harm in the 10 year study period, ethnicity data were available for 94% of individuals. The highest rates of self-harm admission and readmission were found in the White Irish group. Rates of admission and readmission were lower in Black and Asian people compared to White people for both sexes at all ages and in all more specific Black and Asian ethnic groups compared to White British. These differences increased with adjustment for socio-economic deprivation. People of Mixed ethnicity had higher rates of readmission. Rates were highest in the 25–49 age group for Black and Mixed ethnicity men, but in under-25 s for all other groups. There were substantial differences in rates within the broader ethnic categories, especially for the Black and White groups.ConclusionIn contrast to earlier UK studies, self-harm rates were not higher in Black or South Asian women, with lower self-harm admission rates seen in almost all ethnic minority groups. Differences in rates by ethnicity were not explained by socio-economic deprivation. Aggregating ethnicity into broad categories masks important differences in self-harm rates between groups.

Highlights

Self-harm, through both self-injury and overdose [1], has affected over 6% of the population in England at some point in their lifetime [2] and results in over 100,000 hospital admissions [3] each year in England
In women of all ethnicities, rates of self-harm were highest in the 11–24 age group and declined with age
This was the case for White, Asian and Other men, in the Black and Mixed ethnicity groups male rates were highest in the 25–49 age group

Summary

Introduction

Self-harm, through both self-injury and overdose [1], has affected over 6% of the population in England at some point in their lifetime [2] and results in over 100,000 hospital admissions [3] each year in England. Work from the USA has demonstrated differences in rates of self-harm and suicide in different racial and ethnic groups [4]. In the UK, general population surveys, including the most recent Adult Psychiatric Morbidity Survey, have typically been underpowered to detect differences in self-harm. For repetition of self-harm, the South Asian and Caribbean populations of both sexes had lower rates than the White population [7]. More recent studies in a 2015 systematic review [8] have suggested that self-harm rates may no longer be raised in South Asian women but two studies, one in Manchester, Derby and Oxford [9] and the other in London [10] have suggested they may be raised in young Black women. Recent area-level studies in South East London [11] and Manchester [12] have suggested that rates of selfharm may be lower in areas with higher non-White British populations

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