Secular trends in incidence, survival, and health status at diagnosis of dementia in Sweden, 2007–2022

Abstract Background Although past screening cohorts have suggested a decline in the risk of dementia, it is important to monitor the population-level incidence and survival of diagnosed dementia, to inform care utilization and public health policies. This study provides nationwide analyses on time trends in the incidence of dementia diagnosis in Sweden between 2007 and 2022, as well as 5-year survival after a dementia diagnosis. Methods Data from the total Swedish population aged ≥ 61 years during the period 2007–2022 were used. Incident dementia diagnoses were identified from specialist care and dispensed anti-dementia drugs. The annual incidence rate of dementia diagnosis was calculated for the period 2007–2022. The proportion of individuals that survived 5 years after dementia diagnosis was compared across years of diagnosis. Health status at dementia diagnosis was assessed by calculating Charlson Comorbidity Index and Hospital Frailty Risk Score. Results Annual incidence rate of dementia diagnosis decreased from early 2010s and onwards, particularly among older age groups of 80–89 and ≥ 90 years. Mean age at dementia diagnosis remained constant, i.e., 82.2 years during 2007–2009 and 82.2 years during 2019–2022. The proportion of individuals with frailty at diagnosis increased from 74.3% in 2007–2009 to 80.6% in 2019–2022 (odds ratio (OR) = 1.42, 95% confidence interval (CI): 1.39–1.46); the proportion of individuals with comorbidities also increased over the same period. The proportion that survived 5 years since dementia diagnosis remained constant at 33% during 2007–2017 but improved over time when accounting for comorbidity and frailty level at diagnosis. Conclusions While the incidence of dementia diagnosis has declined from early 2010s and onwards, patients diagnosed today are on average frailer and more comorbid than those diagnosed 15 years ago, which partly explains the lack of improvement in dementia survival over time. Enhancing healthcare planning for people with dementia diagnosis and improving their survival is still highly relevant.