Table 2.

Variables and measurement.

Cognition and Eligibility for study	Mini-Mental State examination (MMSE) [22]	The MMSE consists of 11 simple questions or tasks. Test-retest reliability (r > 0.89).
Neuropsychiatric behaviors	Clinician administered Apathy Evaluation Scale (AES) [19]	The AES is an 18-item scale. Internal consistency has an alpha range of 0.86–0.94.Validity: differences found P < .05
Quality of life	Cornell-Brown QOL [24]	Interrater reliability (intraclass r = 0.90) and internal consistency reliability (Cronbach alpha = 0.81).
Depression	The Patient Health Questionnaire [25] (PHQ-9)	Nine-item scale with PHQ-9 score ≥10 had a sensitivity of 88% and a specificity of 88% for major depression.
Executive function	Trail Making B [26]	Validity is high, especially when measuring attention and executive function