I will no doubt attract the ire of those who don't already know that our cats are indoor/outdoor. However, there are still some of us who believe that it is not necessarily wrong to allow cats access to the outdoors on their own terms, and that it's the particular situation/circumstances that should determine what's right for any particular cats. There are two sides, and I just want to be sure they are both represented here.
I have no difficulty with the concept of keeping cats indoors, if your circumstances are such that that is the safer route and is reasonably achieved. But, I also believe that, on the whole, if it's possible to allow access to the outdoors, cats who want to go outdoors (not all do) will be happier and at least no less healthy, for being allowed to make that choice.
My cats are relative youngsters at the moment -- the eldest is 5 1/2, the others are coming up on 4. They have no health problems and haven't had any accidents. Prior to these cats, I had one who lived to 21+, another to almost 16, and another to 13+. They never had accidents, they lived healthy lives, Gryph died of cancer, and the others of old age. Nibs was overweight when he came to us at the age of 6, having been an indoor cat up to that point, and gradually slimmed down from 20 lbs to a svelte 12 1/2 by the time he was 7 or 8, and stayed there to the end. No other cat who has been a member of this family has ever been overweight.
We lost one little darling. Samantha was not quite a year when she disappeared. The coyotes were bold that summer, and we eventually figured that one of them came through this neighbourhood and took her. It was hard. It's still hard. I worry when anyone takes longer than usual to come home. But the way I see it is that, on balance, it's the same as when a neighbourhood kid is abducted and killed. That is tragic. No question about it. But it's one occurrence, and you don't suddenly keep all the rest of the kids in all the time. On balance, my experience -- and I'll take my experience over all the statistics in the world -- is that it is no less safe for my cats to go out than it is for me, as long as they know where home is and how to get in in a hurry if they need to. And they don't get free access until they DO know that.
Let me reiterate, I am not by any means saying it's wrong to keep cats in. I will be the first to acknowledge that they can and do have perfectly happy lives indoors. I just think that it's preferable to allow access to the outdoors where possible, because it's a more natural existence for the cat.
BTW, while my beasts do go out, and are quite pointed in their displeasure when occasionally we keep them in for some specific reason, such as Hallowe'en, they actually stay pretty close to home and spend a fair bit of time inside. But they do like to climb trees, and hunt mice and birds, and they have a strong preference for the facilities that Mother Nature provides -- litter boxes are OK if the alternative is to dig through snow or very wet ground, but that's about it.
My .02 (well, probably more like $2...