Excess acute care costs among U.S. Medicaid Alzheimer's patients in the year prior to diagnosis

Prior research documented that Alzheimer's disease (AD) is associated with increased costs from comorbid conditions. As diagnosis is post-symptomatic, patients developing AD may incur higher acute care medical costs as a result of their condition even prior to diagnosis. This study estimates excess acute care costs among Medicaid AD patients in the year prior to diagnosis. Retrospective analysis of administrative claims data for New Jersey Medicaid (Medicaid) patients, for services provided between 1997-2010. Patients were identified as having AD if they had ICD-9-CM diagnosis code 331.0, or psychiatrist-diagnosed DSM-IV code 290.0, 290.2, 290.3 (age> 65) or 290.1 (age<65) anytime in their claims history. The index date was defined as the earliest claim with any dementia/memory loss diagnosis (ICD-9-CM: 290, 291.2, 292.82, 294, 331, 780.93), preceding AD diagnosis. AD patients were matched to controls with no dementia claims on age, gender, index year, and baseline use of medication (oral antidiabetics, statins, antihypertensives, antidepressants). Institutionalized patients (> 90 days of long-term care) were excluded. Costs for medical services were compared over a 12-month observation period before the index date using t-tests with bias-corrected bootstrapping. Costs were adjusted to 2010 U.S. dollars using the CPI for medical care services. 15,590 AD patients were matched to controls. Average age was 75.5 years, and 75.4% were female. Compared with matched controls, total medical costs over the 12-month pre-index period were $5,399 higher among AD patients ($14,964 vs. $9,565, P <0.001), of which $1,519 (p <0.001) were from homecare and medical daycare services. Emergency department visits accounted for $123 ($715 vs. $591, P <0.001) of the difference, inpatient stays for $390 ($1,832 vs. $1,442, P <0.001), and outpatient visits for $179 ($1,642 vs. $1,463, P = 0.016). Other services (e.g., labs, various clinic visits) accounted for the remainder. Medical costs for fractures and injuries were $221 higher among AD patients (p <0.001). Compared with controls, Medicaid AD patients incurred higher acute care costs in the 12 months prior to their preliminary diagnosis. These findings may be especially relevant in light of new criteria facilitating earlier diagnosis of AD. Earlier diagnosis and better disease management could lead to cost saving interventions.