ABSTRACT
Background: The arterial spin labeling-spatial coefficient of variation (sCoV) is a new vascular magnetic resonance imaging (MRI) parameter that could be a more sensitive marker for dementia-associated cerebral microvascular disease than the commonly used MRI markers cerebral blood flow (CBF) and white matter hyperintensity volume (WMHV). Methods: 195 community-dwelling older people with hypertension were invited to undergo MRI twice, with a three-year interval. Cognition was evaluated every two years for 6-8 years using the mini-mental state examination (MMSE). We assessed relations of sCoV, CBF and WMHV with cognitive decline during follow-up. We also registered dementia diagnoses, up to 9 years after the first scan. In an additional analysis, we compared these MRI parameters between participants that did and did not develop dementia. Results: 136/195 completed the second scan. sCoV and CBF were not associated with MMSE changes during 6-8 years of follow-up. Higher WMHV was associated with declining MMSE scores (-0.02 points/year/ml, 95%CI=-0.03 to -0.00). ScOv and CBF did not differ between participants who did (n=15) and did not (n=180) develop dementia, whereas higher WMHV was reported in participants who developed dementia after the first MRI (13.3 vs 6.1mL, p<0.001). There were no associations between longitudinal change in any of the MRI parameters and cognitive decline or subsequent dementia. Conclusion: Global sCoV and CBF were less sensitive longitudinal markers of cognitive decline and dementia compared to WMHV in community-dwelling older people with hypertension. Larger longitudinal MRI perfusion studies are needed to identify possible (regional) patterns of cerebral perfusion preceding cognitive decline and dementia diagnosis.
ABSTRACT
OBJECTIVE: To determine variation in diagnostic strategies for diagnosing dementia between Dutch hospitals. DESIGN: Descriptive, retrospective research based on claim data of Dutch health insurers. METHOD: Information on the use of diagnostic ancillary services carried out from 2015 to 2018 was collected via national-level insurance claims for patients who received a (new) diagnose-coding for dementia in 2018. Hospitals were included in the analysis if they diagnosed >50 patients with dementia. We distinguished academic medical centres (AMC), non-academic training hospitals (TH) and general hospitals (GH). RESULTS: In 2018, 20.073 new cases of dementia were diagnosed in 71 hospitals. The percentages of patients undergoing MRI/CT-imaging ranged from 37 to 99% (median 76.7%), neuropsychological-assessment from 0-89% (median 31.8%), cerebrospinal fluid examination from 0-14% (median 2.4%), PET/SPECT-imaging from 0-16% (median 6.2%) and electroencephalography from 1-20% (median 5.8%). Practice variation was comparable in AMCs, THs and GHs and was evidently skewed for PET/SPECT-imaging, electroencephalography and cerebrospinal fluid examination. There were no distinct differences according to case-mix characteristics or hospital volume. The percentage of patients subjected to ancillary diagnostic investigations decreased sharply with increasing age. CONCLUSION: In the Netherlands, diagnostic ancillary methods used vary widely between hospitals both in frequency and modality. This variation may be driven by limited evidence of diagnostic accuracy and added value of different diagnostic tests, variations in doctor and patient preferences and differences in available diagnostic techniques per hospital. Further exploration of this heterogeneity may help to identify a strategy that combines the most benefit with the least burden.
