Diagnostic Pathways to Alzheimer Disease: Costs Incurred in a Medicare Population

Disease progression and costs at the 3-year follow-up of the GERAS-US study

Introduction

GERAS-US prospectively characterized clinical and economic outcomes of early symptomatic Alzheimer's disease (AD). Societal cost changes were examined in amyloid-positive patients with mild cognitive impairment due to AD (MCI) and mild dementia due to AD (MILD).

Methods

Cognition, function, and caregiver burden were assessed using Mini-Mental State Examination (MMSE), Cognitive Function Index (CFI), and Zarit Burden Interview, respectively. Costs are presented as least square mean for the overall population and for MCI versus MILD using mixed model repeated measures.

Results

MMSE score and CFI worsened. Total societal costs (dollars/month) for MCI and MILD, respectively, were higher at baseline ($2430 and $4063) but steady from 6 ($1977 and $3032) to 36 months ($2007 and $3392). Direct non-medical costs rose significantly for MILD. Caregiver burden was higher for MILD versus MCI at 12, 18, and 24 months.

Discussion

Function and cognition declined in MILD. Non-medical costs reflect the increasing impact of AD even in its early stages.

HIGHLIGHTS

In the GERAS-US study, total societal costs for patients with mild cognitive impairment due to Alzheimer's disease (MCI) and mild dementia due to Alzheimer's disease (MILD) were higher at baseline but steady from 6 to 36 months.Mini-Mental State Examination (MMSE) and Cognitive Function Index (CFI) worsened; the rate of decline was significant for patients with MILD but not for those with MCI.There was a rise in direct non-medical costs at 36 months for patients with MILD.Caregiver burden was higher for MILD versus MCI at 12, 18, and 24 months.Slowing the rate of disease progression in this early symptomatic population may allow patients to maintain their ability to carry out everyday activities longer.

Clinical and Economic Assessment in Early-Stage Dementia by Severity and Amyloid-β Status: A 5-Year Retrospective Claims Study of GERAS-US Patients

BACKGROUND

The high burden of dementia and Alzheimer's disease (AD) increases substantially as disease progresses. Characterizing early patterns of health care utilization among patients who develop cognitive impairment may deepen our understanding of early disease trajectory and potentially facilitate timely diagnosis and management.

OBJECTIVE

Describe clinical characteristics, healthcare utilization, and costs in early-stage dementia by disease severity and amyloid-β status before enrollment in an observational study (GERAS-US).

METHODS

Consented patients' GERAS-US data were linked to available five-years of Medicare claims history before GERAS-US enrollment. Clinical characteristics, comorbidity, and pre-/post-diagnosis healthcare use and costs were assessed. Continuous and categorical variables were compared between severity and amyloid-status cohorts using t-test and Chi-square statistics; linear regression models were used to compare cost and utilization measures after adjusting for differences in patients' observation time. Relative likelihood of observed diagnoses, comorbidity, and prescription drug use among cohorts were presented as OR and 90% confidence interval (CI).

RESULTS

Of 174 patients clinically diagnosed with early dementia (mild cognitive impairment (MCI): 101; mild dementia (MILD): 73), 55% were amyloid-positive. Memory loss was more likely in MILD versus MCI (OR:1.85, 90% CI 1.10-3.09) and in amyloid-positive versus amyloid-negative cohorts (OR:1.98, 90% CI 1.19-3.29). Mean annual healthcare costs after cognitive impairment/dementia diagnosis were significantly higher for MILD versus MCI ($1191 versus $712, p = 0.067) and amyloid-negative versus amyloid-positive ($1281 versus $701, p = 0.034). Diabetes was more prevalent in MILD and amyloid-negative cohorts.

CONCLUSION

Comorbidity and economic burden increased in earliest stages of MCI and MILD and were higher in patients who were amyloid-negative.

Development and Validation of a Model to Identify Alzheimer's Disease and Related Syndromes in Administrative Data

BACKGROUND

Administrative data are used in the field of Alzheimer's Disease and Related Syndromes (ADRS), however their performance to identify ADRS is unknown.

OBJECTIVE

i) To develop and validate a model to identify ADRS prevalent cases in French administrative data (SNDS), ii) to identify factors associated with false negatives.

METHODS

Retrospective cohort of subjects ≥ 65 years, living in South-Western France, who attended a memory clinic between April and December 2013. Gold standard for ADRS diagnosis was the memory clinic specialized diagnosis. Memory clinics' data were matched to administrative data (drug reimbursements, diagnoses during hospitalizations, registration with costly chronic conditions). Prediction models were developed for 1-year and 3-year periods of administrative data using multivariable logistic regression models. Overall model performance, discrimination, and calibration were estimated and corrected for optimism by resampling. Youden index was used to define ADRS positivity and to estimate sensitivity, specificity, positive predictive and negative probabilities. Factors associated with false negatives were identified using multivariable logistic regressions.

RESULTS

3360 subjects were studied, 52% diagnosed with ADRS by memory clinics. Prediction model based on age, all-cause hospitalization, registration with ADRS as a chronic condition, number of anti-dementia drugs, mention of ADRS during hospitalizations had good discriminative performance (c-statistic: 0.814, sensitivity: 76.0%, specificity: 74.2% for 2013 data). 419 false negatives (24.0%) were younger, had more often ADRS types other than Alzheimer's disease, moderate forms of ADRS, recent diagnosis, and suffered from other comorbidities than true positives.

CONCLUSION

Administrative data presented acceptable performance for detecting ADRS. External validation studies should be encouraged.

Changes in Health Care Use by Mexican American Medicare Beneficiaries Before and After a Diagnosis of Dementia

BACKGROUND

Evidence from predominantly non-Hispanic White cohorts indicates health care utilization increases before Alzheimer's disease and related dementias (ADRD) is diagnosed. We investigated trends in health care utilization by Mexican American Medicare beneficiaries before and after an incident diagnosis of ADRD.

METHODS

Data came from the Hispanic Established Populations for the Epidemiological Study of the Elderly that has been linked with Medicare claims files from 1999 to 2016 (n = 558 matched cases and controls). Piecewise regression and generalized linear mixed models were used to compare the quarterly trends in any (ie, one or more) hospitalizations, emergency room (ER) admissions, and physician visits for 1 year before and 1 year after ADRD diagnosis.

RESULTS

The piecewise regression models showed that the per-quarter odds for any hospitalizations (odds ratio [OR] = 1.62, 95% CI = 1.43-1.84) and any ER admissions (OR = 1.40, 95% CI = 1.27-1.54) increased before ADRD was diagnosed. Compared to participants without ADRD, the percentage of participants with ADRD who experienced any hospitalizations (27.2% vs 14.0%) and any ER admissions (19.0% vs 11.7%) was significantly higher at 1 quarter and 3 quarters before ADRD diagnosis, respectively. The per-quarter odds for any hospitalizations (OR = 0.88, 95% CI = 0.80-0.97) and any ER admissions (OR = 0.89, 95% CI = 0.82-0.97) decreased after ADRD was diagnosed. Trends for any physician visits before or after ADRD diagnosis were not statistically significant.

CONCLUSIONS

Older Mexican Americans show an increase in hospitalizations and ER admissions before ADRD is diagnosed, which is followed by a decrease after ADRD diagnosis. These findings support the importance of a timely diagnosis of ADRD for older Mexican Americans.

Measuring Alzheimer's Disease and Other Dementias in Diverse Populations Using Medicare Claims Data

We examined how methods used for identifying dementia in administrative claims affected dementia incidence across racial/ethnic populations using a 100% sample of Medicare beneficiaries (n = 23,793,452). We found levels differed by method from 3.1% annual incidence to 3.6% in 2014. Dementia incidence declined from 2007 to 2014, but choice of method differentially impacted levels and trends by race/ethnicity. Methods using codes for dementia diagnosis and drugs to treat symptoms identified proportionally more Hispanics and Asians with dementia than other race/ethnicities, while codes for dementia diagnosis, drugs, and symptoms identified proportionally more whites and American Indians/Alaska Natives with dementia than other race/ethnicities.

Retrospective assessment of patient characteristics and healthcare costs prior to a diagnosis of Alzheimer's disease in an administrative claims database

Background

The objective of this study was to examine patient characteristics and health care resource utilization (HCRU) in the 36 months prior to a confirmatory diagnosis of Alzheimer’s disease (AD) compared to a matched cohort without dementia during the same time interval.

Methods

Patients newly diagnosed with AD (with ≥2 claims) were identified between January 1, 2013 to September 31, 2015, and the date of the second claim for AD was defined as the index date. Patients were enrolled for at least 36 months prior to index date. The AD cohort was matched to a cohort with no AD or dementia codes (1:3) on age, gender, race/ethnicity, and enrollment duration prior to the index date. Descriptive analyses were used to summarize patient characteristics, HCRU, and healthcare costs prior to the confirmatory AD diagnosis. The classification and regression tree analysis and logistic regression were used to identify factors associated with the AD diagnosis.

Results

The AD cohort (N = 16,494) had significantly higher comorbidity indices and greater odds of comorbid mental and behavioral diagnoses, including mild cognitive impairment, mood and anxiety disorders, behavioral disturbances, and cerebrovascular disease, heart disease, urinary tract infections, and pneumonia than the matched non-AD or dementia cohort (N = 49,482). During the six-month period before the confirmatory AD diagnosis, AD medication use and diagnosis of mild cognitive impairment, Parkinson’s disease, or mood disorder were the strongest predictors of a subsequent confirmatory diagnosis of AD. Greater HCRU and healthcare costs were observed for the AD cohort primarily during the six-month period before the confirmatory AD diagnosis.

Conclusion

The results of this study demonstrated a higher comorbidity burden and higher costs for patients prior to a diagnosis of AD in comparison to the matched cohort. Several comorbidities were associated with a subsequent diagnosis of AD.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0920-2) contains supplementary material, which is available to authorized users.

Increased Health Care Utilization in Dementia Subtypes Before Diagnosis

INTRODUCTION

Prior studies have reported higher health care utilization (HCU) leading up to diagnosis of the Alzheimer disease and related dementia (ADRD), but none have assessed variation in HCU by ADRD subtype or examined disease-specific HCU. The objectives of this study were to identify ADRD subtypes and: (1) characterize all-cause and (2) disease-specific HCU during the 3 years preceding diagnosis, and (3) determine if HCU varied by ADRD subtype.

METHODS

We used data from the OptumLabs Data Warehouse 2008 to 2014 to identify ADRD subtypes (total N=36,838) using an algorithm based on temporal sequencing of diagnoses and provider type. Annual counts of all-cause and disease-specific HCU in each of the 3 years preceding ADRD diagnosis were regressed on ADRD subtypes with mild cognitive impairment (MCI) as the reference group, year, and other variables.

RESULTS

HCU increased over time, was highest in the outpatient setting, and varied by ADRD subtype. Compared with MCI, highest HCU was observed in vascular and nonspecific dementia. Compared with MCI, most subtypes had elevated disease-specific HCU.

DISCUSSION

Variation in HCU by ADRD subtype points to different pathways to diagnosis and patterns of use.

Economic Burden, Mortality, and Institutionalization in Patients Newly Diagnosed with Alzheimer's Disease

BACKGROUND

Current information is scarce regarding comorbid conditions, treatment, survival, institutionalization, and health care utilization for Alzheimer's disease (AD) patients.

OBJECTIVES

Compare all-cause mortality, rate of institutionalization, and economic burden between treated and untreated newly-diagnosed AD patients.

METHODS

Patients aged 65-100 years with ≥1 primary or ≥2 secondary AD diagnoses (ICD-9-CM:331.0] with continuous medical and pharmacy benefits for ≥12 months pre-index and ≥6 months post-index date (first AD diagnosis date) were identified from Medicare fee-for-service claims 01JAN2011-30JUN2014. Patients with AD treatment claims or AD/AD-related dementia diagnosis during the pre-index period were excluded. Patients were assigned to treated and untreated cohorts based on AD treatment received post-index date. Total 8,995 newly-diagnosed AD patients were identified; 4,037 (44.8%) were assigned to the treated cohort. Time-to-death and institutionalization were assessed using Cox regression. To compare health care costs and utilizations, 1 : 1 propensity score matching (PSM) was used.

RESULTS

Untreated patients were older (83.85 versus 81.44 years; p < 0.0001), with more severe comorbidities (mean Charlson comorbidity index: 3.54 versus 3.22; p < 0.0001). After covariate adjustment, treated patients were less likely to die (hazard ratio[HR] = 0.69; p < 0.0001) and were associated with 20% lower risk of institutionalization (HR = 0.801; p = 0.0003). After PSM, treated AD patients were less likely to have hospice visits (3.25% versus 9.45%; p < 0.0001), and incurred lower annual all-cause costs ($25,828 versus $30,110; p = 0.0162).

CONCLUSION

After controlling for comorbidities, treated AD patients have better survival, lower institutionalization, and sometimes fewer resource utilizations, suggesting that treatment and improved care management could be beneficial for newly-diagnosed AD patients from economic and clinical perspectives.

[Organization of out-patient psychiatric care in dementia and cognitive impairment in aged. Part II: Clinical and economic efficacy of memory clinics and Alzheimer's disease centers]

The part II of the review is focused on a history of developing of memory clinics and Alzheimer's disease centers as well as on the indices of their activity in various countries and in Russia. Approaches to the evaluation of clinical and economic efficacy of new technologies of organization of care and a role of the national programs in solving of the problem of old age dementias were considered.

Direct and indirect cost of managing alzheimer's disease and related dementias in the United States

INTRODUCTION

Care of individuals with Alzheimer's Disease and Related Dementias (ADRD) poses special challenges. As the disease progresses, individuals with ADRD require increasing levels of medical care, caregiver support, and long-term care which can lead to substantial economic burden. Areas covered: In this expert review, we synthesized findings from studies of costs of ADRD in the United States that were published between January 2006 and February 2017, highlighted major sources of variation in costs, identified knowledge gaps and briefly outlined directions for future research and implications for policy and program planning. Expert commentary: A consistent finding of all studies comparing individuals with and without ADRD is that the average medical, non-medical, and indirect costs of individuals with ADRD are higher than those without ADRD, despite the differences in the methods of identifying ADRD, duration of the study, payer type and settings of study population. The economic burden of ADRD may be underestimated because many components such as direct non-medical costs for home safety modifications and adult day care services and indirect costs due to the adverse impact of ADRD on caregivers' health and productivity are not included in cost estimates.

Medicare Expenditure Correlates of Atrophy and Cerebrovascular Disease in Older Adults

Background/Study Context: Magnetic resonance imaging (MRI) markers of cerebrovascular disease and atrophy are common in older adults and are associated with cognitive and medical burden. However, the extent to which they are related to health care expenditures has not been examined. We studied whether increased Medicare expenditures were associated with brain markers of atrophy and cerebrovascular disease in older adults.

METHODS

A subset of participants (n = 592; mean age = 80 years; 66% women) from the Washington Heights Inwood Columbia Aging Project (WHICAP), a community-based observational study of aging in upper Manhattan, received high-resolution MRI and had Medicare expenditure data on file. We examined the relationship of common markers of cerebrovascular disease (i.e., white matter hyperintensities and presence of infarcts) and atrophy (i.e., whole brain and hippocampal volume) with Medicare expenditure data averaged over a 10-year period. Main outcome measures were (a) mean Medicare payment per year across the 10-year interval; (b) mean payment for outpatient care per year; and (c) mean payment for inpatient care per year of visit. In addition, we calculated the ratio of mean inpatient spending to mean outpatient spending as well as the ratio of mean inpatient spending to mean total Medicare spending.

RESULTS

Increased Medicare spending was associated with higher white matter hyperintensity volume, presence of cerebral infarcts, and smaller total brain volume. When examining specific components of Medicare expenditures, we found that inpatient spending was strongly associated with white matter hyperintensity volume and that increased ratios of inpatient to outpatient and inpatient to total spending were associated with infarcts.

CONCLUSION

Medicare costs are related to common markers of "silent" cerebrovascular disease and atrophy.