| Title | Time Trends in the Prevalence of Neurocognitive Disorders and Cognitive Impairment in the United States: The Effects of Disease Severity and Improved Ascertainment. |
| Publication Type | Journal Article |
| Year of Publication | 2018 |
| Authors | Akushevich, I, Yashkin, AP, Kravchenko, J, Ukraintseva, S, Stallard, E, Yashin, AI |
| Journal | J Alzheimers Dis |
| Volume | 64 |
| Issue | 1 |
| Pagination | 137-148 |
| Date Published | 2018 |
| ISSN | 1875-8908 |
| Abstract | BACKGROUND: Trends in the prevalence of cognitive impairment (CI) based on cognitive assessment instruments are often inconsistent with those of neurocognitive disorders (ND) based on Medicare claims records. OBJECTIVE: We hypothesized that improved ascertainment and resulting decrease in disease severity at the time of diagnosis are responsible for this phenomenon. METHODS: Using Medicare data linked to the Health and Retirement Study (1992-2012), we performed a joint analysis of trends in CI and ND to test our hypothesis. RESULTS: We identified two major contributors to the divergent directions in CI and ND trends: reductions in disease severity explained more than 60% of the differences between CI and ND prevalence over the study period; the remaining 40% was explained by a decrease in the fraction of undiagnosed individuals. DISCUSSION: Improvements in the diagnoses of ND diseases were a major contributor to reported trends in ND and CI. Recent forecasts of CI and ND trends in the U.S. may be overly pessimistic. |
| DOI | 10.3233/JAD-180060 |
| Alternate Journal | J. Alzheimers Dis. |
| PubMed ID | 29865067 |
| PubMed Central ID | PMC6214183 |
| Grant List | R56 AG047402 / AG / NIA NIH HHS / United States |
