Prevalence of amyotrophic lateral sclerosis in the United States using established and novel methodologies, 2017

Abstract

Objective:To estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2017 using data from the National ALS Registry (Registry) as well as capture-recapture methodology to account for under-ascertainment. Established in 2010, the Registry collects and examines data on ALS patients in the US to better describe the epidemiology of ALS (i.e. risk factor exposures, demographics).Methods: The Registry compiled data from national administrative databases (from the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration) and a voluntary enrollment data through a web portal (www.cdc.gov/als). To estimate the number of missing cases, capture-recapture methodology was utilized.Results: The Registry conservatively identified 17,800 adult persons (lower-bound estimate) who met the Registry definition of ALS for an age-adjusted prevalence of 5.5 per 100,000 US population. Using capture-recapture methodology, we obtained a "mean case count" of 24,821 ALS cases (prevalence of 7.7 per 100,000 U.S. population) and estimated the upper-bound estimate to be 31,843 cases (prevalence of 9.9 per 100,000 U.S. population). The pattern of patient characteristics (e.g. age, sex, and race/ethnicity) remained unchanged from previous Registry reports. Overall, ALS was most common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of cases were persons aged 18-39 years. Males had a higher prevalence than females overall and across all data sources.Conclusions: Existing Registry methodology, along with capture-recapture methodology, are being used to better describe the epidemiology and demographics of ALS in the US.

Keywords: 2017; Amyotrophic lateral sclerosis; United States; capture–recapture; epidemiology; models; prevalence; risk.

Figure 1.

Number of ALS cases by sex, race, and overall, adjusted for case undercount using the capture-recapture methodology and missing case estimates – National ALS Registry, United States, 2017.

Figure 2.

Estimated prevalence, adjusted prevalence, and mean prevalence per 100,000 of amyotrophic lateral sclerosis by sex, race, and overall – National ALS Registry, United States, 2017^a. Prevalence (light blue) is the estimation without the application of capture–recapture method. Adjusted prevalence (blue) is the upper-bound estimate using capture–recapture method. Mean prevalence (dark blue) is the midpoint estimation between the established algorithm and the estimation obtained by capture–recapture methods.