My Mother went into a nursing home with a rehabilitation wing for five weeks following her most recent stroke. it was her fourth time going through rehab at that home. It is a nice, small place, attached right to the end of a small town hospital. The staff is great and the Physical and Occupational therapists that work with her every day are the absolute best I have ever seen. (Really, the director of therapy is a young "Kid" with a Masters who works really hard, gets along very well with patients and families and understands how to motivate her patients to improve. Her attitude seems infectious, as everybody she works with is also really positive. She is also very understanding and really "gets" patients at different stages of dementia and manages to challenge them all appropriately.)
Even with a great staff, however, possessions wander off. The first time she was there, I brought six pair of pants (Trousers in British?), six shirts and six bras. I had to bring more clothes every week she was there, as the staff was calling me telling me she was out of clothes. She returned with two, three and one. Now, I just bring three of each. That's plenty, as they collect laundry every day except Sunday. I think when she runs out of clothes, it forces the staff to do a lookabout and find her clothes, where if she has plenty, they don't need to worry about it. Why should I go out and buy new stuff just so they can lose it? When they called me up to tell me she was running out of clothes all the time, I told them they needed to find her stuff and not lose it, or she was going to be naked! That seemed to work. I was always polite about it, and nobody ever got mad at me for not bringing more clothes. Most of the families were starting to do the same thing. (We pretty much emptied her closet of things that fit during her first two stays)
I have seen people move into nursing homes with full wardrobes, and three Months later, they had absolutely nothing. I think this is pretty universal and not just limited to the U.S. When you put a whole bunch of confused people together and expect a very small staff to keep them all safe and organized, clothing and possessions end up pretty low on the priority list.