MOUNT VERNON — No one knows precisely how many older Americans are being abused, neglected or exploited, but the best estimates, according to the National Center on Elder Abuse, are that between 1 million and 2 million Americans age 65 or older have been injured, mistreated or otherwise exploited by someone on whom they depended for care or protection.

Elder abuse is defined as physical, emotional or sexual abuse; exploitation; abandonment; and neglect or self-neglect. A random telephone survey conducted in 2008 by the National Institute of Justice showed 11 percent reported at least one form of mistreatment from the categories of emotional, physical or sexual mistreatment, and potential neglect. Another 5.2 percent reported financial exploitation by family.

Elder abuse does not involve every person over the age of 60; a key provision is that the individual is in a vulnerable position.

Locally, about 5 percent of the criminal cases that come through the Knox County Prosecutor’s Office involve elder abuse. Knox County Prosecutor John Thatcher said these include misuse of credit cards, attempted robbery, theft and patient abuse.

Nationally, there are no official numbers because the definition of elder abuse varies, there is no uniform state reporting system and comprehensive national data are not collected. Clarifying and defining these issues are two of the goals of the Ohio Attorney General’s Elder Abuse Commission.