Progression of mild cognitive impairment to dementia in German specialist practices

Abstract

The goal of this study was to estimate the rate of the progression of mild cognitive impairment to dementia and identify the potential risk factors in German specialist practices from 2005 to 2015. This study included 4633 patients aged 40 years and over from 203 neuropsychiatric practices, who were initially diagnosed with mild cognitive impairment between 2005 and 2013. The primary outcome was diagnosis of all-cause dementia recorded in the database until the end of the five-year follow-up period. Cox regression models were used to examine mild cognitive impairment progression to dementia when adjusted for confounders (age, sex, and health-insurance type). The mean age was 68.9 years and 46.6% were men. After the five-year follow-up period, 38.1% of women and 30.4% of men had been diagnosed with dementia ( p < 0.001). The share of subjects with dementia increased with age, rising from 6.6% in the age group of ≤ 60 years to 64.7% in the age group of > 80 years ( p < 0.001). Men were at a lower risk of being diagnosed with dementia than women (hazard ratio = 0.86). Patients in the age groups 61–70, 71–80, and > 80 years also had a higher risk of developing this psychiatric disorder, with hazard ratios ranging from 3.50 to 11.71. Finally, mild cognitive impairment was less likely to progress to dementia in people with private health-insurance coverage than in people with public health-insurance coverage (hazard ratio = 0.69). Around one in three patients developed dementia in the five years following mild cognitive impairment diagnosis. Sex, age, and type of health insurance were associated with this risk.