title: Detection limit used for early warning in public health surveillance.
abstract: A theory of detection limit, developed in analytical chemistry, is applied to public health surveillance to detect an outbreak of national emergencies such as natural disaster and bioterrorism. In this investigation, the influenza epidemic around the Tokyo area from 2003 to 2006 is taken as a model of normal and large-scale epidemics. The detection limit of the normal epidemic is used as a threshold with a specified level of significance to identify a sign of the abnormal epidemic among the daily variation in anti-influenza drug sales at community pharmacies. While auto-correlation of data is often an obstacle to an unbiased estimator of standard deviation involved in the detection limit, the analytical theory (FUMI) can successfully treat the auto-correlation of the drug sales in the same way as the auto-correlation appearing as 1/f noise in many analytical instruments.
authors.affiliation: Kosumo Chouzai Yakkyoku Co., Ltd., 2-129-3 Miyahara, Kita, Saitama 331-0812, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kobari
authors.forename: Kazuo
authors.initials: K
authors.lastname: Iwaki
authors.forename: Tomomi
authors.initials: T
authors.lastname: Nagashima
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Ishii
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yajima
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D016303:Clinical Pharmacy Information Systems; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D053139:Oseltamivir / Q000191:economics / Q000600:supply & distribution*; D011159:Population Surveillance / Q000379:methods*; D011634:Public Health / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D053139:Oseltamivir