Development of a web-based survey for monitoring daily health and its application in an epidemiological survey

Background: Early detection of symptoms arising from exposure to pathogens, harmful substances, or environmental changes requires timely intervention. The administration of web-based questionnaires is a potential method for collecting information from a sample population. Objective: To develop a web-based daily questionnaire for health (WDQH) for symptomatic surveillance. Methods: We adopted two different survey methods to develop the WDQH: an internet panel survey, which included subjects already registered with an internet survey company, and the Tokyo Consumers’ Co-operative Union (TCCU) internet survey, in cooperation with the Japanese Consumers’ Co-operative Union, which recruited participants by website advertising. The internet panel survey participants were given a fee everyday for answers, and the survey was repeated twice with modified surveys and collection methods; Internet Panel Survey I was conducted every day, and Internet Panel Survey II was conducted every 3 days to reduce costs. We examined whether the survey remained valid by reporting health conditions on day 1 over a 3-day period, and whether the response rate would vary among groups with different incentives. In the TCCU survey, participants were given a fee only for initial registering, and health information was provided in return for survey completion. The WDQH included the demographic details of participants and prompted subjects to answer questions about the presence of various symptoms by e-mail. Health information collected by the WDQH was then used for the syndromic surveillance of infection. Results: Response rates averaged 47.3% for Internet Panel Survey I, 42.7% for Internet Panel Survey II, and 40.1% for the TCCU survey. During a seasonal influenza epidemic, a rapid increase in the number of patients with fever was reported by the WDQH using the early aberration reporting system. Conclusions: We developed a health observation method based on self-reporting by subjects via the internet. We validated the usefulness of the WDQH via its practical use in syndromic surveillance.博士（医学）・甲第581号・平成24年3月16日The definitive version is available at "http://www.jmir.org/2011/3/e66/