Clinical factors associated with activities of daily living and their decline in patients with severe dementia

Background To identify the clinical factors affecting activities of daily living (ADL) at baseline and after 6 months. Methods We conducted a single-centre observational study at two time points across 6 months (baseline and after 6 months) from April 2015 to March 2017. in a 270-bed rural recuperation hospital at Hyogo prefecture in Japan. The total number of participants was 131 (male 33, female 98; mean age: 87.0 +/- 7.0; mild and moderate dementia, 38; severe dementia, 93). Measurement scales used were Personal Self-Maintenance Scale (PSMS) for assessing ADL, Mini-Mental State Examination and Cognitive Test in Severe Dementia (CTSD) for cognitive function, Neuropsychiatric Inventory-Nursing Home version and Cornell Scale for Depression in Dementia (CSDD) for behavioural/psychological symptoms of dementia, Mini Nutritional Assessment Short form (MNA-SF) for nutritional status, Pain Assessment in Advanced Dementia for pain, and Charlson comorbidity index (CCI) and the number of illness categories based on Cumulative Illness Rating Scale Geriatrics for comorbidities. Multiple regression analyses identified the association between PSMS score as the dependent variable and other variables as independent variables. Results In participants with severe dementia, the PSMS scores at baseline were significantly associated with CTSD, CCI, MNA-SF, and CSDD scores. In the longitudinal analysis, only CTSD score was significantly associated with PSMS score after 6 months. It is noteworthy that for participants with severe dementia, the only factor associated with ADL after 6 months was cognitive function, as assessed by CTSD score. Conclusions The most important factor predicting functional decline is cognitive function, even at the severe and profound stage.