Temporal Trends in Dementia Incidence in Sweden: Insights from NEAR Data

Abstract Background This study investigates the temporal trends of dementia incidence in Sweden over a span of 35 years, drawing on data from the National E-Infrastructure for Aging Research (NEAR). Methods Our comprehensive analysis encompassed over 10,000 participants aged 50 and above. We estimated dementia incidence rates across the study period, considering birth cohort, age, and sex while controlling for potential confounders. Additionally. We explored potential modifiers influencing the estimated trend of dementia incidence. Results The analysis reveals a notable decline in dementia incidence rates, particularly among individuals born in more recently. Octogenarians born in the 1920-1930 cohort had a 74% lower dementia incidence rate compared to their counterparts born before 1900. Similarly, nonagenarians born in the 1910-1920 cohort experienced a 45% lower incidence rate. We further investigate determinants influencing this declining trend, shedding light on various factors shaping the observed patterns. Conclusions The incidence rate of dementia in Sweden has shown a consistent decline over the past 35 years, with a notable birth cohort effect indicating lower rates among individuals born more recently. This finding suggests evolving factors in lifestyle, healthcare, or environmental conditions contributing to improved cognitive health outcomes. Key Messages • These findings underscore the importance of proactive public health measures aimed at sustaining and enhancing cognitive health outcomes among aging populations. • Understanding the temporal dynamics and underlying factors driving these trends can inform strategies for promoting healthy aging and improving the quality of life for older adults.