Health Research and Policy


DATE: October 31, 2013
TIME: 1:15 - 3:00 pm
LOCATION: Medical School Office Building, Rm x303
TITLE: Little Bodies and Little Waves: Searching for Transient Cyclicity in Prematurity Using Wavelets
SPEAKERS: Philip T. Labo and James Holland Jones
Department of Anthropology, Stanford University

We describe the application of wavelet techniques to birthweight trend data. These data describe weekly, biweekly, or monthly proportions of low and very low birthweight babies (those weighing less than 2500 or 1500 grams at birth) born in California municipalities over the past forty or so years. We ask: Do these data show periodicity? Is such periodicity long-observed or furtive? Weak or strong? We consider such questions locally (by county and zip code) and then statewide across all counties and zip codes. To what extent do areas of high periodicity and low periodicity cluster together geographically? How can we quantify and compare such geographic clustering across cases of interest? What etiological factors are suggested by observed statewide patterns in periodicity?


  1. This is joint work with Jamie Jones (Anthropology) and Paul Wise (CHP/PCOR).
  2. Intellectual and financial support for this work comes from the Prematurity Center in the Stanford University School of Medicine.
Suggested readings:
Cazelles B, M Chavez, GC Magny, JF Guégan & S Hales. Time-dependent spectral analysis of epidemiological time-series with wavelets. Journal of the Royal Society Interface, 4 (2007) 625–636.

Friedman JH & LC Rafsky. Graph-theoretic measures of multivariate association and prediction. The Annals of Statistics, 11:2 (1983) 377–391.

Torrence C & GP Compo. A practical guide to wavelet analysis. Bulletin of the American Meteorological Society, 79:1 (1998) 61–78.

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