How Many People in the USA Have Essential Tremor? Deriving a Population Estimate Based on Epidemiological Data

BACKGROUND: Essential tremor (ET) is often reported to be among the most prevalent movement disorders, yet the precise number of cases in the USA is not known. The goal of the current analyses was to use published data from epidemiological studies to derive an estimate of the number of people currently residing in the USA who have ET. METHODS: A PubMed search was conducted to identify population-based prevalence studies of ET. The methodology of 34 identified studies was assessed. Then the three most methodologically rigorous studies were selected, and age-specific prevalence data were abstracted. US census data from 2012 were used to determine the population in the USA by 10-year age categories. RESULTS: Using data from three studies, estimates of the number of ET cases (2012) ranged from 6.38 to 7.63 million (mean = 7.01 million). This corresponds to approximately 2.2% of the US population. DISCUSSION: Knowing the number of ET cases in the USA is important in terms of estimating the medical burden on communities and society, and providing an objective metric on which to base health resource planning.