Associations between physical function and depression in nursing home residents with mild and moderate dementia: a cross-sectional study

Objectives The primary aim of this study is to describe depression and physical function in nursing home residents with dementia, as well as to examine the associations between depression and balance function, lower limb muscle strength, mobility and activities of daily living. The secondary aim is to examine the differences in physical function between the groups classified as depressed and not depressed. Design The study has a cross-sectional design. Setting A convenience sample of 18 nursing homes in, and around, Oslo, Norway, participated. Participants We included 170 nursing home residents aged 60-100 years with mild or moderate degree of dementia defined by a score of 1 or 2 on the Clinical Dementia Rating Scale (CDR). Outcome measures Assessments used were Cornell Scale for Depression in Dementia (CSDD), Berg Balance Scale (BBS), 'the 6-metre walking test' (walking speed), 30 s Chair Stand Test (CST) and the Barthel Index (BI). Results Nursing home residents with dementia are a heterogeneous group in terms of physical function and depression. By applying the recommended cut-off of >= 8 on CSDD, 23.5% of the participants were classified as being depressed. The results revealed significant associations between higher scores on CSDD (indicating more symptoms of depression) and lower scores on BBS (95% CI -0.12 to -0.02, p=0.006), 30 s CST (95% CI -0.54 to -0.07, p=0.001) as well as maximum walking speed (95% CI -4.56 to -0.20, p=0.003) (indicating lower level of physical function). Conclusion Better muscle strength, balance and higher walking speed were significantly associated with less depressive symptoms. The potential interaction of dementia with poor physical function and depression indicates an area to explore in future epidemiological studies with a prospective design.