Dr. Jeffrey Cummings (Brain Health), recently published an article, in Frontiers in Psychiatry. It studied the use of the SDI to identify disrupted sleep in dementia patients in nursing homes, which was proven to be useful when done properly. According to the study, the SDI’s high internal consistency and convergent validity proves it can serve as a clinical cut-off for the presence of disturbed sleep in institutionalized dementia patients to be a SDI-summed product score of five or more.