Factors associated with COVID-19 in people with Parkinson's disease: a systematic review and meta-analysis

BACKGROUND: There is a debate about whether there is an increased risk of COVID-19 infection in people with Parkinson's disease (PD), possibly due to associated factors. This study aimed to systematically review the factors associated with COVID-19 in people with PD. METHODS: The search was carried out in PubMed, Scopus, and Web of Science until November 2020 (updated until April 1, 2021). Observational studies that analyzed factors associated with COVID-19 in people with PD were selected and revised. RESULTS: The authors included six studies (4 case-controlled studies and 2 cross-sectional studies) in the qualitative and quantitative syntheses. Authors found that the following factors were associated with COVID-19 in people with PD: obesity (OR: 1.79, 95% CI: 1.07 to 2.99, I(2) : 0%), any pulmonary disease (OR: 1.92, 95% CI: 1.17 to 3.15, I(2) : 0%), COVID-19 contact (OR: 41.77, 95% CI: 4.77 - 365.56, I(2) : 0%), vitamin D supplementation (OR: 0.50, 95% CI: 0.30 to 0.83, I(2) : 0%), hospitalization (OR: 11.78, 95% CI: 6.27 to 22.12, I(2) : 0%), and death (OR: 11.23, 95% CI: 3.92 to 32.18, I(2) : 0%). Authors did not find significant association between COVID-19 and hypertension, diabetes, cardiopathy, cancer, any cognitive problem, dementia, chronic obstructive pulmonary disease, renal or hepatic disease, smoking, and tremor. CONCLUSIONS: Meta-analyses were limited by the number of events and some methodological limitations. Despite that, the authors assessed available evidence, and the results may be useful in future health policies.