Parkinson's disease and COVID-19: a systematic review and meta-analysis

Background Patients with Parkinson's disease (PD) are at higher risk of COVID-19 infection as most of them are at older age. The goal of this study is to update the pooled prevalence of COVID-19 infection in patients with PD. Methods Two researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, Google Scholar, and also gray literature including references of the included studies which were published before September 2021. We extracted data regarding the total number of participants, first author, publication year, the country of origin, mean age, number with COVID-19, symptoms, hospitalization, and death. Results We found 1693 articles by literature search; after deleting duplicates, 798 remained. Thirty articles remained for meta-analysis. The pooled prevalence of COVID-19 infection in PD cases was 5% (95%CI: 4-6%) (I-2 = 98.1%, P < 0.001). The pooled prevalence of fever in cases with PD was 4% (95%CI: 2-6%) (I-2 = 96%, P < 0.001). The pooled prevalence of cough in cases with PD was 3% (95%CI: 2-4%) (I-2 = 95.9%, P < 0.001). The pooled prevalence of hospitalization in cases with COVID-19 infection was 49% (95%CI: 29-52%) (I-2: 93.5%, P < 0.001). The pooled prevalence of mortality in COVID-19 cases was 12% (95%CI: 10-14%) (I-2 = 97.6%, P < 0.001). Conclusion The results of this systematic review and meta-analysis show that the pooled prevalence of COVID-19 infection in PD cases is 5% besides hospitalization and mortality rates which are 49% and 12%.