Surveillance of coronavirus disease 2019 in general population using an online questionnaire: A report from 18161 respondents in China.

BACKGROUND: The recent outbreak of coronavirus disease 2019 (COVID-19) has become an international pandemic. So far little is known about the role of an internet approach in COVID-19 surveillance. OBJECTIVE: We aim to investigate whether an online survey can provide population-level information for observing prevalence trends during early phase of outbreak and identifying potential risk factors of COVID-19 infection. METHODS: A 10-item online questionnaire was developed according to medical guidelines and relevant publications. It was distributed between 24 January and 17 February 2020. Characteristics of respondents and temporal changes of various questionnaire-derived indicators were analyzed. RESULTS: A total of 18161 questionnaires were returned, including 6% (1171) from Wuhan City. Geographical distributions of the respondents were consistent with population per province (R(2) = 0.61, P < .001). History of contact significantly decreased with time, both outside Wuhan City (R(2) = 0.35, P = .002) and outside Hubei Province (R(2) = 0.42, P < .001). Percentage of fever respondents peaked around February 8 (R(2) = 0.57, P < .001) and increased with history of contact in the areas outside Wuhan City (risk ratio: 1.31, 95% confidence interval: 1.13 - 1.52, P < .001). Male sex, advanced age, and lung diseases were associated with a higher risk of fever in the general population with history of contact. CONCLUSIONS: This study shows the usefulness of an online questionnaire for surveillance of outbreaks like COVID-19 by providing information about trends of the disease and aiding in identifying potential risk factors. CLINICALTRIAL: