OTTAWA -- Only a small proportion of elder-abuse cases investigated by police result in criminal charges because victims want to maintain family relationships and fear winding up in seniors' homes, a federal study suggests.

Justice Department researchers who looked at 453 cases of allegedly abused elderly people handled by Ottawa police over a five-year period found charges were laid in 17 per cent of files.

That's considerably lower than the one-quarter of police probes that typically lead to charges.

In more than half of the elder-abuse cases in which no one was charged, there was either insufficient evidence or the victim refused to co-operate with police.

Possible explanations include a desire to maintain family ties, fear and anxiety about institutionalization and loss of independence, as well as factors such as financial dependency, disability or illness, the study says.

"The vulnerabilities that put older Canadians at risk of victimization can also create barriers to criminal investigations and the criminal justice system as a response."

One police officer told the researchers the elderly are reluctant to pursue charges against their children and as a result police spend a large amount of time walking elders through the benefits of doing so, including the help available for those who are abusive.

According to the 2011 census, there are five million Canadians aged 65 and older -- a segment of the population that's growing rapidly, the study notes.

Slightly more women than men -- 52 per cent female versus 48 per cent male -- were accused of abuse in the Ottawa cases, which covered 2005 to 2010 and were stripped of personal information before being made available to the researchers by the police force's elder-abuse section.

Women, however, represented 70 per cent of victims -- probably because females make up a disproportionate segment of the senior population, the study says.

Male accused were more likely to target family or friends, while female accused more often victimized people under their care in an institutional setting, the researchers found.

The most common type of offence was financial abuse, followed by verbal, physical and a small percentage of sexual abuse cases. In many cases involving money, the victim was initially unaware their resources were being pilfered.

Aside from reluctance of some elderly victims to press criminal cases, the data often revealed barriers to investigation -- the most common being mental health issues followed by victim fear.

In cases where no charges were laid, police sometimes referred the victim to social services or other support groups, or the accused may have been verbally warned about their alleged behaviour.

"It takes several weeks or months to investigate an elder-abuse case," one officer told the authors, "and there is no cookie-cutter method of investigating elder abuse."

The study says further research into the barriers facing police investigating elder abuse would be beneficial, as officers face unique challenges in such cases.

Research on the files of other elder-abuse police units across the country could also help determine whether the trends are unique to Ottawa or common to other cities.

The study suggests:

-- Adding a full-time elder-abuse specialist to police staff to alleviate barriers to criminal probes as well as free up officers to zero in on the criminal aspects of the cases;

-- Ensuring agencies and programs that provide support and assistance to elderly victims are well-resourced.