title: Spectral analysis based on fast Fourier transformation (FFT) of surveillance data: the case of scarlet fever in China.
abstract: Many infectious diseases exhibit repetitive or regular behaviour over time. Time-domain approaches, such as the seasonal autoregressive integrated moving average model, are often utilized to examine the cyclical behaviour of such diseases. The limitations for time-domain approaches include over-differencing and over-fitting; furthermore, the use of these approaches is inappropriate when the assumption of linearity may not hold. In this study, we implemented a simple and efficient procedure based on the fast Fourier transformation (FFT) approach to evaluate the epidemic dynamic of scarlet fever incidence (2004-2010) in China. This method demonstrated good internal and external validities and overcame some shortcomings of time-domain approaches. The procedure also elucidated the cycling behaviour in terms of environmental factors. We concluded that, under appropriate circumstances of data structure, spectral analysis based on the FFT approach may be applicable for the study of oscillating diseases.
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.affiliation: School of Community Health Sciences, University of Nottingham, Nottingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Yang
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
authors.forename: X
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Disease Control and Emergency Response Office, Chinese Centre for Disease Control and Prevention, Beijing, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Feng
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.affiliation: School of Mathematics, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Ren
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
authors.forename: X
authors.initials: X
authors.lastname: Li
mesh_terms: D002681:China / Q000453:epidemiology; D004812:Epidemiologic Methods; D005583:Fourier Analysis; D006801:Humans; D015994:Incidence; D011159:Population Surveillance; D012541:Scarlet Fever / Q000453:epidemiology*