Engineering Researcher Draws A Broader Picture From Data In AIDS Studies, Drug Trials

Health researchers wondered whether African infants grew more slowly if their mothers consumed insufficient vitamin A during pregnancy. Drug addiction experts wanted to see whether a new medication would ease withdrawal pain. Researchers studying men's health needed to know how HIV infection affects immune cell counts over a period of years.

To help make sense of the raw data they collected, scientists in each of these studies called in Colin Wu, a biostatistics expert from The Johns Hopkins University's Whiting School of Engineering. Wu, an associate professor of mathematical sciences, uses a relatively new form of data analysis called curve estimation to produce clearer pictures of how health changes over time.

Standard statistical methods provide just a snapshot of health conditions at a single point in time. In the growth study, for example, standard methods could have told researchers the average weight, exactly two years after birth, of children born to HIV-positive, vitamin A-deficient mothers. But Wu's technique yielded a curve that spanned the length of a project. It let researchers compare average growth figures for the children two months after birth, 23 months after or anywhere in between.

The curve produced by Wu and his partners is a very useful research tool, he says. "The shape of growth over time cannot be told by conventional methods," he explains. "Children's growth over time may not look like a straight line. Our method will show what it does look like."

Wu and colleagues Donald R. Hoover, John A. Rice and Li-Ping Yang reported on the mathematical foundation for this study in the December 1998 issue of Biometrika. Working with data compiled in a Johns Hopkins School of Public Health study in Central Africa, the researchers looked at weight figures collected from 328 inf
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Contact: Phil Sneiderman
prs@jhu.edu
410-516-7160
Johns Hopkins University
29-Jan-1999