Although the Nurses' Observation Scale for Inpatient Evaluation is a commonly used tool in nursing home studies of behavioral disturbances of dementia, Dr. Luxenberg noted that this instrument is relatively weak compared with other rating scales. In most nursing homes in the United States, as well as in other countries, nursing aides are the primary caregivers and therefore the primary informants. These aides often have a cultural background different from that of other nursing staff members and may be less likely to accurately report on behavioral problems. Dr. Luxenberg provided an example of a nursing aide who reported that a patient chanted every morning and then refused assistance with bathing and dressing. When the investigator observed this behavior, he found that the patient was praying and refused to bathe until he had completed his prayers.