Dementia care needs in an area population: case register data and morbidity survey estimates

To compare case register data on the frequency and distribution of known dementia cases in a metropolitan area population with expected total numbers computed from a national disability survey.

Known cases were enumerated by a cross-sectional census of the Camberwell Dementia Register. Expected total numbers were calculated using the Cognitive Disability (CD) Planning Model, based on the OPCS national survey of disability, 1985-86.

Cases ascertained by the Dementia Register census comprised one-fifth of expected total prevalence. The proportion of such cases was higher for persons in long-stay care (1 in 3) than for those in private households (1 in 7). According to the CD Planning Model, cases known to specialist agencies were on average no more severely disabled and dependent than those who were unknown. In terms of absolute numbers, the district nursing and home help services appeared to be the most important untapped sources of case detection, but other research indicates that general practice contacts (not included in the planning model) may be at least equally important.

At any given time, a high proportion of dementia cases, whether in long-stay care or in the community, will be outside the purview of specialist services. Primary care agencies are a major potential source, and a systematic health screening of persons aged over 75 years could be used to realize this potential.