Healthcare costs incurred by patients before entering GERAS‐US, a prospective, observational study of early Alzheimer’s disease: Impact of disease severity and amyloid status

Abstract

AbstractBackgroundGERAS‐US (NCT02951598) is a longitudinal, prospective US cohort study assessing healthcare resource use (HCRU) and costs in clinician‐diagnosed, early‐stage Alzheimer’s disease (AD). This study analyzed HCRU and costs incurred by patients before and after cognitive impairment (CI)/AD diagnosis, before entering the GERAS‐US study.MethodData of GERAS‐US participants who consented for this addendum study were linked to Medicare claims data, for up to 5 years before baseline study visit (2013–2017). GERAS‐US study classified severity using Mini‐Mental State Examination (MMSE) and Functional Activities Questionnaire (FAQ) scores. Mild cognitive impairment (MCI) was defined as MMSE: 24–30 and FAQ: <6, and mild dementia (MILD) was defined as MMSE: 20–30 and FAQ: ≥6. Amyloid status (positive/negative) was determined by PET scan. Participants selected in this analysis required Medicare fee‐for‐service eligibility (Parts A and B enrollment) for ≥1 month before baseline visit. Mean HCRU and costs before and after CI/AD diagnosis were compared by severity and amyloid status, adjusting for length of fee‐for‐service history before or from the month of first CI/AD diagnosis, respectively. Differences in costs were assessed using general linear model regression analyses and healthcare costs per patient per month (PPPM) were calculated. Descriptive, Chi‐square (categorical variables), and t‐test (continuous variables) analyses were conducted.ResultHealthcare costs of 174 patients were assessed by severity and amyloid status (Table). Mean total all‐cause healthcare cost incurred PPPM post CI/AD diagnosis was greater for MILD versus MCI cohort (P=.067), and for patients with amyloid‐negative versus ‐positive status (P<.05). Post CI/AD diagnosis, patients in the MILD cohort with amyloid‐negative status incurred greatest mean PPPM total healthcare costs (MILD amyloid‐negative, $1842; MILD amyloid‐positive, $695; P=.014; not shown). Home health cost post CI/AD diagnosis was a significant factor driving differences between MCI and MILD cohorts ($9 vs. $120, P=.014), and between amyloid‐negative and ‐positive cohorts ($124 vs. $19, P=.022) (not shown).ConclusionDifferences in total healthcare costs were greatest post CI/AD diagnosis, with greater costs being incurred by MILD versus MCI, and amyloid‐negative versus amyloid‐positive cohorts. After diagnosis, home health cost was a major factor significantly driving cost differences.