Two things come to mind in response to your question. One is that the need for institutionalization is often driven by a whole combination of factors, and many of them are caregiver-focused. So if a caregiver who has been managing someone who has a progressive dementia has a fall and ends up in hospital, then it's more likely that the veteran who had the dementia is going to have to go into a long-term-care home, because the caregiving support systems aren't there any more.
So one issue is the progression of the disorder, and the other issue is the stability of the environmental supports. There are some things that can happen in the course of dementia that make it increasingly difficult for people to be managed at home, regardless of whether the situation is stable or not, and that's when some of what they call the psychological and behavioural symptoms of dementia start to become more prominent, which happens as the dementia gets worse. This is the wandering, the aggression, the inappropriate behaviours and hallucinations--the kinds of behaviours and symptoms that can become a lot more difficult to manage in a home and community environment. So if the disease progresses so that those start to become more a part of the symptom picture, that may be what triggers the need for institutionalization, even though the family or the spouse hasn't changed.
On the other hand, the disease could be fairly stable and the caregiving situation could change, and all of a sudden that requires institutionalization.
To go back to your previous question, about what research there's been, well, I don't think there's been a lot of focus on determining whether there has been a higher incidence of dementia in veteran versus non-veteran populations. There has been quite a bit of research done, and quite a bit of this has come out of the United States, actually. They've looked at older veterans who have managed quite well through their middle-aged years--they worked, they had a good career and a good early retirement--and then they developed dementia. The combination of the dementia and what that brings in terms of the ability to cope and to reason and to function, together with the losses that come with aging, can create a pretty volatile situation that becomes quite difficult to handle. So you can get a situation whereby the normal stresses of aging are exacerbated.