Descriptions of changes in personal care must take into account an individual's life-long standard, but most people conform to the social norm. Changes in personal care therefore can provide important insights into staging. In mild dementia, there are usually no changes, although sometimes, with attention to detail being impaired, subtle problems can be observed - missed spots with shaving, dirt accumulated in skin folds, a stain that does not get cleaned properly. With moderate dementia, people need prompting to do their personal care. With severe dementia, they need progressive assistance.
Dr. Barry Reisberg of New York University pioneered descriptions of the staging of dementia based on decline in functional capacity. His excellent short description of functional decline in dementia (the Functional Assessment Staging Tool) notes that requiring prompting to change clothes is a hallmark of moderate dementia. My colleagues and I have been impressed by the uncanny characteristicness of this change.