This analysis of Medicare claims data found a significant prevalence of concurrent use of dementia medication with acetylcholinesterase inhibitors and anticholinergic medications. This medication combination is a frank medical error that the authors describe as a never event. Despite this, coprescription occurred in 44% of those prescribed dementia medication, and this medication error was more common in the southeastern and midwestern regions of the United States compared to the northeast or western regions.

This study discovered that the wrong time of administration was the most common cause of medication errors in the assisted living setting. However, given that most medications administered in this setting were deemed low risk, the errors were likely of little clinical significance.