Living condition, weight loss and cognitive decline among people with dementia.

This was an observational study, not a randomised trial, so patients were not assigned to live in a nursing home or alone; it cannot prove that the setting caused faster cognitive decline or BMI loss. The analysis excluded 253 of 681 patients because they died or had additional health problems, so the remaining sample may not represent all dementia patients. Only 80 patients lived alone, and the authors say this was a main limitation, so the alone group is small. The study did not measure diet, physical activity, social contact, family visits or nursing home quality, so it cannot identify why the differences occurred. BMI fell overall, but BMI values ranged from 21 to 38 and the authors reported no evidence of malnutrition, so weight loss here should not be read as undernutrition.

The authors declared no conflict of interest. The patients came from the first author's private surgery.

Do not conclude that nursing homes or living alone caused faster cognitive decline. This was an observational study, patients were not assigned to living conditions, and the paper did not measure diet, activity or social contact. It also reported no evidence of malnutrition, because BMI values were between 21 and 38 and no patient was underweight.