A correct diagnosis of dementia is important in order to provide the patient and relatives
with right information, and to give adequate treatment and support, but also to improve
research and further development of treatment. Alzheimer's disease (AD) is the cause of
nearly 2/3 of cases of dementia. Current diagnostic methods to ensure accurate diagnosis
include analysis of cerebrospinal fluid and molecular PET, but these methods are expensive
and not widely available.
Progress has been made in the development of blood-based diagnostic biomarkers for
Alzheimer's disease. It will lead to significant simplification and improvement of clinical
practice if simple blood tests that can be taken in general practice can provide a reliable
diagnosis of Alzheimer's disease.
Several biomarkers (including phosphorylated tau 181, phosphorylated tau 217, phosphorylated
tau 231, plasma glial fibrillary acidic protein, plasma β-amyloid 42 to β-amyloid 40 ratio,
and plasma neurofilament light) has documented to be useful to distinguish Alzheimer's
dementia from non-Alzheimer's dementia in research cohorts with a high prevalence of AD. This
project aims to analyze the diagnostic ability of such biomarkers in a primary care cohort
with a lower prevalence of AD.
The Stavanger region in Norway will be the catchment area for recruitment of study
participants. The region is geographically distinct with 373,000 inhabitants, 15
municipalities with 320 GPs in 94 clinics, all served by one hospital. Consequently, the
region offers unique opportunities for community-wide implementation research.
All General Practitioners (GPs) in the region will be invited to, upon consent, select
participants for the study. To reflect real-life medical practice in primary care, broad
inclusion criteria have been chosen. Blood samples will be taken at the GP offices. First,
the robustness of the samples regarding temperature, time and transportation to the
laboratory will be studied. Second, the results of the blood samples will be compared with
the results of standard diagnostic procedures at the memory outpatient clinic at the
hospital. A random sample of an equal number of patients with positive and negative blood
biomarker test-results will undergo blinded specialist examination, including MRIs of the
brain and analysis of the cerebrospinal fluid for Alzheimer biomarkers. The diagnosis made by
the specialists will then be compared to the blood-test results in order to estimate the
positive and negative predictive value of such biomarkers for the diagnosis of AD in general
practice.