End-Stage Dementia Spark of Life: Reliability and Validity of the "GATOS" Questionnaire

Abstract

Background: Fl oor effects are present in most dementia assessment tools as dementia progresses and the in-depth assessment of patients considered more or less on vegetative state is questionable. Objective: To develop a questionnaire (the "Gatos Clinical Test-GCT") for the assessment of end-stage demented patients. Methods: Five hundred patients with dementia of various causes and an MMSE score between 0 and 2 were enrolled in the study. The GCT consists of 14 closed type questions rated on a Likert scale. The total score is used to evaluate patient's dementia. Various aspects of validity and reliability (including face, content and structural validity as well as test-retest reliability) were examined. Results: Three subscales "Autonomy/Alertness", "Gnosias" and "Somatokinetic function" were defined, with a Cronbach equal to 0.851, 0.756 and 0.598 respectively. The GCT subscales and total score were statistically significant higher in patients with MMSE score 1 or 2 compared with those with MMSE score 0 (p < 0.0005). Patients with GCT total score less than 12.5 had 75% probability to have zero MMSE score. Conclusion: The "GATOS" questionnaire is a valid and reliable test for patients with severe dementia, aiming at identification of those patients who could sustain some quality of life. It is a relatively short and easy to administer tool. As dementia prevalence is expected to rise further worldwide we believe that GCT could offer valuable services to health professionals, caregivers and patients.