Headache Symptom Versus Headache Disorders: Impact on COVID-19 Survival

Background: COVID-19 has not impacted people or countries uniformly. This disparity has prompted investigations to identify clinical and genetic predictors of COVID-19 mortality. Headache, a COVID-19 symptom, has been associated with positive disease prognosis in small cohorts, but larger confirmatory data-sets are lacking. Moreover, the global predisposition to experience primary headache disorders might be correlated with variances in COVID-19 mortality rates. Methods: We conducted a meta-analysis of studies of COVID-19 inpatient survival that also reported headache as a COVID-19 symptom. Separately, using a generalized additive model regression (GAM), we analysed data across 171 nations to identify variables which impact COVID-19 mortality rates. We performed similar analyses of seasonal influenza mortality. Prevalence data were extracted from the Global Health Data Exchange. Findings: We meta-analysed 48 studies and observed a significantly higher risk ratio of survival (RR:2·178 [1·882-2·520], p