ABSTRACT
OBJECTIVE: To explore the possibility that the mortality risk of mild cognitive impairment (MCI) as diagnosed using Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria (DSM-5-MCI) will be higher than using Petersen's criteria (P-MCI) and to report the population-attributable fraction (PAF) of mortality due to MCI. METHODS: A representative community sample of 4,803 individuals aged 55 or more years was interviewed and then followed for 17 years. Standardized instruments were used in the assessment, including the Geriatric Mental State-AGECAT, and research psychiatrists diagnosed P-MCI and DSM-5-MCI cases following operationalized criteria. Mortality information was obtained from the official population registry. Kaplan-Meier age-adjusted survival curves were built for the MCI diagnostic groups, and Cox proportional hazards regression models were used to calculate the hazard ratio of death in participants with MCI relative to those without. We also estimated the PAF of mortality due to specific MCI diagnostic groups. RESULTS: Compared with noncases, the mortality rate ratio was approximately double in DSM-5-MCI individuals (2.3) than in P-MCI individuals (1.2). In the multivariate statistical analysis, a significant association between each diagnostic category and mortality was observed but was only maintained in the final model in DSM-5-MCI cases (hazard ratio: 1.24). The PAF of mortality due to MCI was approximately 1% in both MCI categories. CONCLUSION: The mortality risk in comparison with noncases was higher in DSM-5-MCI than in P-MCI. The PAF of mortality in DSM-5-MCI individuals was ~ 1% over a 17-year period.
