Epidemiology, Co-Morbidities, and Medication Use of Patients with Alzheimer's Disease or Vascular Dementia in the UK

Abstract

Epidemiologic studies on age-specific incidence rates (IRs) separating Alzheimer's disease (AD) and vascular dementia (VaD) in the UK are scarce. We sought to assess IRs of AD and VaD in the UK and to compare co-morbidities and medication use between patients with AD, VaD, or without dementia. We identified cases aged ≥65 years with an incident diagnosis of AD or VaD between 1998 and 2008 using the General Practice Research Database (GPRD). We assessed IRs, stratified by age and gender, matched one dementia-free control patient to each demented patient, and analyzed co-morbidities and medication use. We identified 7,086 AD and 4,438 VaD cases. Overall, the IR of AD was 1.59/1,000 person-years (py) (95% CI 1.55-1.62) and the IR of VaD 0.99/1,000 py (95% CI 0.96-1.02). For AD, IRs were higher for women than for men, but not for VaD. Except for orthostatic hypotension, the prevalence of all cardiovascular (CV) co-morbidities and exposure to CV drugs was lower in patients with AD than in corresponding controls, whereas the opposite was true for VaD. The lower prevalence of CV diseases in patients with AD may be a true finding or the result of a channeling effect, i.e., the possibility that demented patients with CV diseases may be more likely diagnosed with VaD than AD.

Gout and the risk of Alzheimer's disease: a population-based, BMI-matched cohort study

“…The incidence rates (IRs) of AD per 1000 person-years in our cohort according to age categories <75 years and 75–90 years were 0.6 and 4.0 cases among men and 1.2 and 4.8 cases among women, respectively. These rates were comparable with previous estimates from the GPRD database24 and other population-based studies 25…”

Cardiovascular medication burden in dementia disorders: a nationwide study of 19,743 dementia patients in the Swedish Dementia Registry

“…AD patients used to be considered as the healthiest group of dementia patients [29], since it has been reported that AD is associated with fewer comorbidities compared with the other dementia subtypes [30,31]. These results are not in line with more recent papers that have reported the opposite [32,33].…”

Benzodiazepine Use and Risk of Developing Alzheimer’s Disease or Vascular Dementia: A Case–Control Analysis

“…First, we cannot rule out the possibility of some AD and VaD case misclassification as not all dementia diagnoses can be accurately assigned by subtype. However, to reduce the possibility of misclassification when classifying AD or VaD cases, we applied a published validated algorithm [23]. Second, we were not able to control for certain potential confounders, such as level of education, marital status, or socioeconomic status, since these factors are not routinely recorded in the CPRD.…”

“…Patients with less than 3 years of active history in the database prior to the diagnosis date were excluded, as were those with a diagnosis of HIV/AIDS, alcoholism, drug abuse, multiple sclerosis, motor neuron disease, or Down's syndrome. To increase the probability of including only well-defined AD or VaD cases, a validated algorithm was applied, described in detail elsewhere [23]. In brief, this algorithm was based on recordings of specific dementia tests [e.g.…”