Risk of Death Among Persons with Alzheimer's Disease: A National Register-Based Nested Case-Control Study

Abstract

Few studies have reported the risk of death related to Alzheimer's disease (AD) in large population-based cohorts. The objective of this study was to analyze the impact of AD on all-cause mortality in a nationwide sample of persons with AD. Community-dwelling persons with AD and an equal number of individually matched (age, gender, and region of residence) control persons without AD were identified from the registers of Social Insurance Institution of Finland at the end of 2005. Deaths in this sample (n = 56,041, mean age 79.7 years, 67.8% women) during a 57-month follow-up period were recorded. Using a nested case-control design, unadjusted and adjusted (cardiovascular disease, cancer, diabetes, and asthma and/or COPD) hazard ratios (HR) with 95% confidence intervals (CI) were computed using proportional hazards regression. The results were categorized according to age at death (<80, 80 to 89, ≥ 90 years) and duration of AD (≤ 3, 4 to 6, ≥ 7 years). The unadjusted HR for death associated with AD was 2.03 (95% CI: 1.97 to 2.09). The HR was highest in the youngest age category [HR = 3.46 (95% CI: 3.18 to 3.77)], and still significantly elevated in the oldest age category [HR = 1.50 (95% CI: 1.41 to 1.60)]. Comorbidity adjustments did not change the HRs, and even a short duration of AD (≤ 3 years) was associated with a significantly increased risk of death. In conclusion, AD was associated with an increased risk of death that was more pronounced at younger ages and existed even after a recent diagnosis of AD.

Impact of High Risk Drug Use on Hospitalization and Mortality in Older People with and without Alzheimer’s Disease: A National Population Cohort Study

“…This observation is supported by studies demonstrating the independent effects of AD on hospitalization [36] and mortality [37]. In a recent study conducted in the same Finnish population, AD was associated with an increased risk of mortality, independent of comorbidities [38].…”

Angiotension receptor blockers reduce the risk of dementia

“…According to the BNHI regulations, the clinical diagnosis must conform to the criteria of the ICD-9, the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV), or the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorder Association (NINDS-ADRDA), and must include a history of dementia for more than 6 months. Other causes of dementia must be excluded [26,28,29]. Every case of AChE inhibitor drug therapy has to be reviewed for the diagnosis and severity of Alzheimer's disease and be approved by the experts (neurologists or psychiatrists) of the BNHI before the first prescription.…”

Use of existing data sources in clinical epidemiology: Finnish health care registers in Alzheimer&rsquo;s disease research &ndash; the Medication use among persons with Alzheimer&rsquo;s disease (MEDALZ-2005) study

“…On average, persons with Ad were twice as likely to die during the follow-up in comparison to the matched population 34. The risk difference was more pronounced at younger ages (<80 years old) and even a short duration of Ad (≤3 years) was associated with a significantly increased risk of death.…”

“…The association persisted after adjusting for comorbidities, suggesting that Ad has an important and independent impact on mortality. Altogether, 18,395 (32.7%) persons (11,726 and 6,669 with and without Ad, respectively) died during 2006–2009 34. Persons who died during follow-up were a mean age of 3.8 years older and were more likely to be men and have Alzheimer’s disease and other chronic comorbidities (Table 3).…”