2024/11/04 by David Bruckman, Ikjae Lee, Jesse D. Schold +5 · 5 citations
Medicine · #Myasthenia Gravis and Thymoma #Parkinson's Disease and Spinal Disorders #Coagulation, Bradykinin, Polyphosphates, and Angioedema
paper · doi:10.1212/wnl.0000000000210005
BACKGROUND AND OBJECTIVES: Epidemiologic studies suggest increasing incidence and prevalence of myasthenia gravis (MG) among the elderly population outside the United States. We aimed to provide an estimation of MG incidence and prevalence and their trend among the Medicare Fee-For-Service (FFS)-covered elderly US population. METHODS: We performed a retrospective longitudinal study using Medicare claims data (2006-2019). Study-eligible beneficiaries were aged 65 years and older, had at least 1 month of FFS Part A/B coverage, and were without any health maintenance organization insurance coverage. Study-eligible beneficiaries were aggregated into 2-year periods from 2006-2007 through 2018-2019. MG cases were ascertained using a validated algorithm of 2 MG claims within each 2-year period, from 2 outpatient office visits or a combination of 1 inpatient admission and 1 outpatient office visit, separated by ≥ 28 days. Period prevalence was calculated from MG-ascertained cases divided by FFS Part A/B beneficiaries and reported as cases per 100,000 population. Incident cases were determined among MG prevalent cases if the initial MG claim occurred in that period after a full calendar year since coverage initiation. Incidence was calculated as case counts per 100,000 at-risk beneficiary person-years (PYs) in each period excluding 2006-2007. Trends of prevalence and incidence over time were examined with Poisson regression. All-cause mortality of each 2-year period was calculated. RESULTS: = 0.18). DISCUSSION: Increasing trends in MG prevalence and incidence in the elderly US population, with variation in rates of certain subgroups, are confirmed in this 14-year period.