Incremental dementia-related expenditures in a medicaid population.

OBJECTIVES: With the growing number of older adults, understanding expenditures associated with treating medical conditions that are more prevalent among older adults is increasingly important. The objectives of this research were to estimate incremental medical encounters and incremental Medicaid expenditures associated with dementia among Indiana Medicaid recipients 40 years or older in 2004. METHODS: A retrospective cohort design analyzing Indiana Medicaid administrative claims files was used. Individuals at least 40 years of age with Indiana Medicaid eligibility during 2004 were included. Patients with dementia were identified via diagnosis codes in claims files between July 2001 and December 2004. Adjusted annual incremental medical encounters and expenditures associated with dementia in 2004 were estimated using negative binomial regression and zero-inflated negative binomial regression models. RESULTS: A total of 18,950 individuals (13%) with dementia were identified from 145,684 who were 40 years or older. The unadjusted mean total annualized Medicaid expenditures for the cohort with dementia ($28,758) were significantly higher than the mean expenditures for the cohort without dementia ($14,609). After adjusting for covariates, Indiana Medicaid incurred annualized incremental expenditures of $9,829 per recipient with dementia. Much of the annual incremental expenditure associated with dementia was driven by the higher number of days in nursing homes and resulting nursing-home expenditures. Drug expenditures accounted for the second largest component of the incremental expenditures. On the basis of disease prevalence and per recipient annualized incremental expenditures, projected incremental annualized Indiana Medicaid spending associated with dementia for persons 40 or more years of age was $186 million. CONCLUSIONS: Dementia is associated with significant expenditures among Medicaid recipients. Disease management initiatives designed to reduce nursing-home use among recipients with dementia may have much potential to decrease Medicaid expenditures associated with dementia.

Impact of patient selection criteria on prevalence estimates and prevalence of diagnosed dementia in a Medicaid population.

OBJECTIVES: This study estimated the prevalence of diagnosed dementia among Indiana Medicaid beneficiaries in 2004. The dependence of prevalence estimates upon use of several patient selection criteria to identify patients with dementia also was evaluated. METHODS: Indiana Medicaid claims data were analyzed for the period July 1, 2002 to December 31, 2004. An expert panel survey was conducted to assess perceived specificity of ICD codes used in previous studies to define dementia. Prevalence estimates were calculated with varying levels of each selection criteria, that is, ICD code set, interval of data examined, and number of occurrences of dementia-related claims. To assess specificity and sensitivity of the dementia patient selection criteria, Minimum Data Set data for a subset of beneficiaries that resided in a nursing home any time in 2004 were examined. RESULTS: Depending on the patient selection criteria used, estimates of prevalence of diagnosed dementia for individuals 40 years old or older varied from 7.7% to 15.3%, whereas prevalence estimates for individuals 60 years old or older varied from 14.5% to 26.6%. When the following selection criteria were used: (1) occurrence of one or more dementia-related claims, (2) the expert panel ICD set, and (3) up to 30 months of data for defining dementia, the prevalence estimates in the Indiana Medicaid population were 10.9% for individuals 40 years old or older and 20.3% for individuals 60 years old or older. CONCLUSIONS: Careful selection of claims-based criteria for identifying patients with dementia is important because the criteria may affect estimates by 100%. Prevalence of diagnosed dementia among Indiana Medicaid beneficiaries was 3 to 4 times higher than the reported prevalence from a decade ago in Medicaid populations of other states, even when the same patient selection criteria were used. A number of factors beyond increased occurrence of the disease including increased screening, greater likelihood of recording dementia codes in claims, or other factors may be responsible. The combination of patient selection criteria used in this study had good sensitivity, specificity, and accuracy when compared with Minimum Data Set data.