Variability in case definition obscures direct comparison, although the prevalence of elder abuse is broadly similar throughout Europe and North America. To date there are few data from developing countries. With the exception of the United States, a paucity of robust national incidence data reflects widespread absence of formal mechanisms for case reporting and validation.

Differing study populations and sampling techniques have also contributed to a range of prevalence and incidence estimates⁵. The work by Thomas⁶ described a range of estimates across studies of between 2% and 10%. This suggests elder abuse is sufficiently prevalent to be regularly encountered by all health care workers looking after older adults. Lachs and Pillemer⁵ estimate that for every 20–40 older adults seen, there is one victim of abuse.

Likelihood of abuse increases with age⁷. Older women are more likely than men to be victims⁸ but this observation may be confounded by greater likelihood of longer life expectancy³. Poverty elevates the risk of abuse⁷.

Shared living is considered a major risk factor, due to increased opportunities for contact. Living alone is associated with lower risk, except for financial abuse^9,10. Social isolation from other family members and friends (apart from the perpetrator(s)) is an additional risk factor¹¹.

Dementia is associated with higher rates of abuse than in cognitively intact older adults^11,12. Cooper et al.¹³ described an abuse prevalence of 52% from carers among a population with dementia. They discussed the ‘spectrum of behaviour’ in patterns of abuse, with 34% reporting seemingly important levels of abuse and lower rates of more serious abuse or physical harm. Behaviour disturbance, agitation or aggression is likely to fuel caregiver abuse. Carers are themselves also at risk of physical abuse from those with challenging behaviours. In one series, a third of carers reported physical abuse by the patient, which in turn was associated with abuse of the patient by the carer¹⁴.

Interestingly, neither the level of dependency of an older adult on a caregiver nor the severity of caregiver stress have been identified as risk factors in a variety of research studies⁵. Similarly there is no proven relationship between degree of physical impairment and abuse.

Abuse in institutional care settings has been associated with a number of factors: inadequate staffing levels, frequent use of non-permanent staff, poor staff training, development and supervision, and inadequate incident reporting systems.

Vulnerability to abuse has been associated with certain personality traits¹⁵. Victims of psychological abuse have less ability to control problem situations and tend to react aggressively when feeling anger or frustration. In contrast, physical abuse victims pursue passive or avoidant behaviour, while financial abuse victims possess negative beliefs of self-efficacy and turn aggression or frustration on themselves.

Greater understanding of abusive situations has focused attention on those perpetrating abuse. Nearly half of all abusers are related to the victim, but only a small minority are the primary carer³. Carers who do abuse suffer social isolation, feel unsupported and may be financially dependent on the person they are abusing.