Supplementary Material for: Odds of Medical Comorbidities in Essential Tremor: Retrospective Analysis of a Large Claims Database in the United States

Introduction: Essential tremor (ET) is the most common tremor disorder, estimated to affect 7 million individuals in the U.S. There is little empirical evidence on comorbidities among this population beyond higher prevalence of brain-related and stress-related disorders. This study aims to examine differences in the prevalence of the 31 Elixhauser comorbidities among ET patients compared to statistically similar control patients. Methods: An extract from Optum’s de-identified Clinformatics® Data Mart Database (CDM) from 2018-2019 of adults aged 40 to 80 years with at least one claim with an ET diagnosis was propensity score matched to controls. Logistic regression was used to generate doubly robust adjusted odds ratios for each of the 31 Elixhauser comorbidities. Results: In these analyses, ET patients had significantly greater adjusted odds of depression, alcohol abuse, and other neurological disorders, as well as chronic pulmonary disease, renal failure, hyperthyroidism, and cardiac arrhythmias relative to controls. They also had lower odds of uncomplicated diabetes, congestive heart failure, metastatic cancer, paralysis, peripheral vascular disease, and fluid and electrolyte disorders. Conclusion: A number of recent studies, including our own, suggest that psychiatric, neurologic and stress-related disorders may be more prevalent among ET patients than controls. Additional differences in the prevalence of a range of medical comorbidities have also been variably reported across studies, suggesting that some combination of these might be more prevalent. Further studies would be of value in sorting through these associations.