Prevalence and risk of violence against adults with disabilities: a systematic review and meta-analysis of observational studies

Summary

Background

About 15% of adults worldwide have a disability. These individuals are frequently reported to be at increased risk of violence, yet quantitative syntheses of studies of this issue are scarce. We aimed to quantify violence against adults with disabilities.

Methods

In this systematic review and meta-analysis, we searched 12 electronic databases to identify primary research studies published between Jan 1, 1990, and Aug 17, 2010, reporting prevalence estimates of violence against adults (aged mainly ≥18 years) with disabilities, or their risk of violence compared with non-disabled adults. We included only studies reporting violence occurring within the 12 months before the study. We assessed studies with six core quality criteria, and pooled data for analysis.

Findings

Of 10 663 references initially identified, 26 were eligible for inclusion, with data for 21 557 individuals with disabilities. 21 studies provided data suitable for meta-analysis of prevalence of violence, and ten for meta-analysis of risks of violence. Pooled prevalence of any (physical, sexual, or intimate partner) recent violence was 24·3% (95% CI 18·3–31·0) in people with mental illnesses, 6·1% (2·5–11·1) in those with intellectual impairments, and 3·2% (2·5–4·1) in those with non-specific impairments. We identified substantial heterogeneity in most prevalence estimates (I² >75%). We noted large uncertainty around pooled risk estimates. Pooled crude odds ratios for the risk of violence in disabled compared with non-disabled individuals were 1·50 (95% CI 1·09–2·05) for all studies combined, 1·31 (0·93–1·84) for people with non-specific impairments, 1·60 (1·05–2·45) for people with intellectual impairments, and 3·86 (0·91–16·43) for those with mental illnesses.

Interpretation

Adults with disabilities are at a higher risk of violence than are non-disabled adults, and those with mental illnesses could be particularly vulnerable. However, available studies have methodological weaknesses and gaps exist in the types of disability and violence they address. Robust studies are absent for most regions of the world, particularly low-income and middle-income countries.

Funding

WHO Department of Violence and Injury Prevention and Disability.

Introduction

Roughly 15% of adults worldwide have a disability.¹ This prevalence is predicted to increase because of ageing populations, the increased risk of disability in elderly people, and the worldwide rise in chronic diseases such as cancer, diabetes, cardiovascular disease, and mental illnesses.2, 3 Approaches to disability increasingly emphasise environmental and social factors, with recognition that “disability results from the interaction between persons with impairments and attitudinal and environmental barriers that hinders their full and effective participation in society on an equal basis with others”.⁴ Protection of the rights of individuals with disabilities, and enablement of their full participation in society has become a major global priority, underpinned by the UN Convention on the Rights of Persons with Disabilities.⁴ To support action on this priority, the World Report on Disability¹ gathered evidence about the magnitude of disability worldwide, its effect on well-being, and how the barriers faced by individuals with disability can be overcome.

About half a million adults die every year because of interpersonal violence;³ millions more suffer non-fatal violence and the resulting health and socio-occupational consequences. People with disabilities seem to be at an increased risk of interpersonal violence¹ because of several factors: exclusion from education and employment, the need for personal assistance with daily living, reduced physical and emotional defences, communication barriers that hamper the reporting of violence, societal stigma, and discrimination.5, 6 Furthermore, rising numbers of media reports emphasise cases of physical violence, sexual abuse, and hate crime inflicted on individuals with disabilities in homes, institutions, communities, and other settings.7, 8, 9, 10 However, whether this increase indicates a rising prevalence of violence against individuals with disabilities, more consistent reporting to authorities, or greater media coverage than previously is unclear.

Although an increasing amount of research has been done to quantify violence against individuals with disabilities, study methods and the definitions of disability and violence vary widely, and no quantitative syntheses of this evidence have been done. Understanding of the magnitude of violence against affected groups is the first step in the public health approach to violence prevention.¹¹ This step is a basic prerequisite to understand risk and protective factors, develop and rigorously assess interventions, and implement effective programmes to prevent violence. Thus, to support the World Report on Disability, we did a systematic review and meta-analysis of studies of violence against adults with disability. We aimed to identify the characteristics and coverage of research for the prevalence and risk of violence against adults with disabilities; assess the quality of this research; and synthesise evidence on the prevalence and risk of violence against adults with disabilities to identify knowledge gaps and research priorities.