Dementia is, in most cases, characterized by a progressive decline in cognitive function. In Europe, it is estimated that between six to ten million persons have dementia
. The prevalence of dementia increases with age, from approximately 1.5% in persons aged 60–69 years to 40% in persons 90 years and older
. The prevalence of dementia is found to be high in nursing home residents in the Western countries
[3–6]. Studies in Norway have indicated that more than 80% of nursing home residents have dementia
In general, dementia will negatively affect the person’s ability both to function adequately in everyday life and to perform personal activities of daily living (P-ADL), such as bathing, dressing, eating, grooming, ambulation/transferring and toileting
Dementia and the accompanying P-ADL impairment increase the risk of being admitted to nursing home care
[18, 19] as increasing P-ADL impairment increases the need of care. Lower P-ADL functioning increases the burden for the patients, their family, the professional caregivers and society as a whole
[15, 20, 21]. Furthermore, P-ADL impairment in older persons increases the risk of mortality
Up to now, relatively few studies have explored how P-ADL functioning changes over time in nursing home residents with dementia
. An early study explored P-ADL decline in nursing home residents without assessing dementia and or cognitive impairment
. Others have explored if the presence of dementia (yes/no) in nursing home residents at baseline was important for later P-ADL decline
[23, 27, 28]. Diverging results were reported. Furthermore, prospective register studies of nursing home residents with and without dementia have studied the association between P-ADL decline and the degree of cognitive impairment with a follow-up period of three months to one year. These studies found that a decline of P-ADL functioning was explained by the degree of P-ADL impairment and degree of cognitive impairment at baseline
[29–32]. None of the register studies explored the importance of medical co-morbidity to a P-ADL decline.
A recent six-month follow-up study of long-term residents with dementia reported that a decline in P-ADL functioning was associated with the patients’ degree of dementia
. However, this study had excluded the residents with physical co-morbidities and did not study the influence of neuropsychiatric symptoms on P-ADL development. Information about medical co-morbidity and neuropsychiatric symptoms should be included, since studies report that such symptoms may have importance for P-ADL functioning
[31, 33, 34]. Other risk factors for a decline in P-ADL functioning over time in nursing home residents may be age, ethnicity, gender, marital status and education
[22, 27, 28, 31, 32, 35]. Protective factors for a decline in P-ADL have also been reported, such as the long-term use of antidementia medication
[20, 36, 37].
A number of disease specific and generic P-ADL indexes have been developed, validated and found sensitive to small but significant changes in persons’ ability to perform P-ADL
[20, 38]. Even so, several studies of P-ADL decline in nursing home residents have used single items
[26, 32, 33, 35] rather than P-ADL indexes covering a range of P-ADL functions
[23, 31]. The Physical Self-Maintenance Scale is one of the shorter recommended P-ADL indexes
, which has been frequently used in Scandinavian studies
[7, 8, 39, 40].
To our knowledge no long-term follow-up of nursing home residents has been conducted including both a measure of cognition and physical co-morbidities. Thus, our aim was to study the association between degree of dementia, both at baseline and over more than four years, and the development in P-ADL functioning measured by the Physical Self-Maintenance Scale (P-ADL score), adjusting for a number of other variables know to have an influence on P-ADL functioning in nursing home residents with dementia. We hypothesize that P-ADL functioning in persons with dementia living in nursing homes will decline over time, and that this decline will be associated with a worsening of dementia, the neuropsychiatric symptom load, medication and physical co-morbidity.