Advancing Sexual and Reproductive Health and Rights
 
Perspectives on Sexual and Reproductive Health
Volume 39, Number 3, September 2007

Using Clinical Classification Trees to Identify Individuals at Risk of STDs During Pregnancy

By Trace S. Kershaw, Jessica Lewis, Claire Westdahl, Yun F. Wang, Sharon Schindler Rising, Zohar Massey and Jeannette Ickovics

CONTEXT: Few studies have used classification tree analysis to produce empirically driven decision tools that identify subgroups of women at risk of STDs during pregnancy. Such tools can guide care, treatment and prevention efforts in clinical settings.

METHODS: A sample of 647 women aged 14–25 attending two urban obstetrics and gynecology clinics in 2001–2004 were surveyed in their second and third trimesters. Baseline predictors at the individual,dyad,and familyand community levels were used to develop a classification tree that differentiated subgroups of women by STD incidence at 35 weeks’ gestation. Logistic regression analyses were conducted to assess whether the classification tree groups or commonly used risk factors better predicted STD incidence.

RESULTS: Nineteen percent of women had an incident STD during pregnancy. Classification tree analysis identified three subgroups with a high STD incidence (33–61%), one with a moderate incidence (16%) and three with a low incidence (6–11%).Women in subgroups with high STD incidence included those not living with the partner withwhom they conceived and those who had a moderate or a high level of depression, a history of STDs and a low level of social support. A logistic regression model using groups defined by the classification tree analysis had better predictive ability than one using common demographic and sexual risk predictors.

CONCLUSION: This classification tree identified risk factors not captured by traditional risk screenings, and could be used to guide STD treatment, care and prevention within the prenatal care setting. Perspectives on Sexual and Reproductive Health, 2007, 39(3):141–148







 

 
 

Trace S. Kershaw is assistant professor, Jessica Lewis and Zohar Massey are research associates, and Jeannette Ickovics is professor—all with the Department of Epidemiology and Public Health, and the Center for Interdisciplinary Research on AIDS, Yale University, New Haven, CT. Claire Westdahl is assistant professor and director of nursemidwifery, and Yun F. Wang is assistant professor—both with the Emory University School of Medicine, Atlanta. Sharon Schindler Rising is executive director, Centering Pregnancy and Parenting Association, Chesire, CT.