PROVIDENCE, RI — Alzheimer’s disease and related dementias (ADRD) often are identified using a list of claims codes and a fixed lookback period of three years of data.
A new study in the American Journal of Alzheimer’s Disease & Other Dementias questioned, however, whether a one-year lookback or an approach using all-available lookback data could be beneficial based on different research questions.1
Researchers from the Alpert Medical School of Brown University and the VA Center of Innovation in Long-Term Services, both in Providence, sought to compare one-year and all-available lookback approaches to ascertaining ADRD compared to the standard three-year approach.
The study team used a cohort of 373,897 veterans hospitalized for heart failure. It reported that results “suggested high agreement (93% or greater) between the lookback periods. The 1-year lookback period had lower sensitivity (60%) and underestimated the prevalence of ADRD. These results suggest that 1-year and all-available lookback periods are viable approaches when using claims data.”
Background information in the article pointed out that Alzheimer’s disease and Related Dementias (AD/ADRD) are the most common forms of dementia, resulting in $321 billion in annual direct medical costs in the United States.
In 2022, more than 6.5 million Americans aged 65 and older were living with Alzheimer’s Disease, a number projected to exceed 13.8 million by 2060.
“Variability in clinical presentation, paired with high rates of comorbid illness pose a challenge to early and accurate AD/ADRD diagnosis,” the authors wrote. “In fact, it has been reported that up to 50% of all dementia cases are not identified by primary care providers. Further, when cognitive decline is detected, misdiagnosis is prevalent.”
The study advised that an analysis of the National Alzheimer’s Coordinating Center (NACC) patient database from 2005-2010 produced an AD diagnosis sensitivity rate of 71-87% and a specificity rate of 44-71% using the National Institute of Neurological Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association (NINDS-ADRDA) as well as the National Institute on Aging (NIA)-Reagan criteria highlighting the limitations of current diagnostic practices.
The authors explained that misdiagnosis of AD has contributed to excess Medicare expenditures of $9,500-$14,000 per patient per year.
The study also noted that cardiovascular disease “represents one of the top concurrent medical comorbidities in ADRD.1 Heart failure patients are of particular concern when studying ADRD, as a meta-analysis showed they have nearly a 60% higher risk of ADRD, and a separate meta-analysis showed the prevalence of dementia in heart failure patients is up to 41%. Additionally, the prevalence of heart failure is projected to increase 46% between 2012 and 2030, which may further increase already surging incidence rates of ADRD”
- Kunicki ZJ, Bayer T, Jiang L, Bozzay ML, Quinn MJ, De Vito AN, Emrani S, Erqou S, McGeary JE, Zullo AR, Duprey MS, Singh M, Primack JM, Kelso CM, Wu WC, Rudolph JL. Comparing Lookback Periods to Ascertain Alzheimer’s Disease and Related Dementias. Am J Alzheimers Dis Other Demen. 2023 Jan-Dec;38:15333175231199566. doi: 10.1177/15333175231199566. PMID: 37650437.
