Trends in Co-morbid Dementia and Chronic Kidney Disease

Background: Little is known about the population of Medicare beneficiaries with both chronic kidney disease (CKD) and Alzheimer's disease and related dementias (ADRD).

Methods: Using data from Medicare fee-for-service (FFS) beneficiaries aged 65 and over identified through 2011-2019 Master Beneficiary Summary File (MBSF), we estimated the size, growth, and racial-ethnic characteristics of the ADRD and CKD populations. Individuals were classified as having ADRD and CKD based on CMS Chronic Conditions Data Warehouse (CCW) indicators in the MBSF Chronic Conditions file.

Results: Among FFS beneficiaries, the prevalence of CKD has increased from 17.5% in 2011 to 27.9% in 2019, and the prevalence of ADRD has decreased over that time from 13.3 to 12.5%. The prevalence of individuals with co-morbid ADRD and CKD has risen from 4.4 to 6.3% which represents 1.72 million older adults. Black and Hispanic individuals have the highest prevalence of co-morbid CKD and ADRD, averaging 10.0% and 9.0% in 2019, respectively, compared to other racial-ethnic groups (≤ 7.2% all others). In addition, among those previously diagnosed with ADRD, the proportion with co-morbid CKD has been steadily increasing from 25.5% in 2011 to 44.4% in 2019. While the proportion of individuals with ADRD who have co-morbid CKD has increased across all race-ethnicities, it is highest in Black and Hispanic individuals (56.7 and 51%, respectively in 2019).

Conclusion/relevance: The prevalence of Medicare FFS enrollees with both ADRD and CKD is increasing. Although the ADRD prevalence has declined, there is a rising number of individuals with CKD who are diagnosed with ADRD and a rising proportion of those with ADRD who also have CKD. Due to shared clinical and demographic risk factors, interventions to reduce CKD progression could also delay ADRD onset. In patients with both advanced ADRD and advanced CKD, clinicians and policymakers should focus on treatment options that consider both co-morbidities.