Assessing the Validity and Reliability of Three Indicators Self-Reported on the Pregnancy Risk Assessment Monitoring System Survey

Abstract

We investigated the reliability and validity of three self-reported indicators from the Pregnancy Risk Assessment Monitoring System (PRAMS) survey. We used 2008 PRAMS (n=15,646) data from 12 states that had implemented the 2003 revised U.S. Certificate of Live Birth. We estimated reliability by kappa coefficient and validity by sensitivity and specificity using the birth certificate data as the reference for the following: prenatal participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC); Medicaid payment for delivery; and breastfeeding initiation. These indicators were examined across several demographic subgroups. The reliability was high for all three measures: 0.81 for WIC participation, 0.67 for Medicaid payment of delivery, and 0.72 for breastfeeding initiation. The validity of PRAMS indicators was also high: WIC participation (sensitivity = 90.8%, specificity = 90.6%), Medicaid payment for delivery (sensitivity = 82.4%, specificity = 85.6%), and breastfeeding initiation (sensitivity = 94.3%, specificity = 76.0%). The prevalence estimates were higher on PRAMS than the birth certificate for each of the indicators except Medicaid-paid delivery among non-Hispanic black women. Kappa values within most subgroups remained in the moderate range (0.40-0.80). Sensitivity and specificity values were lower for Hispanic women who responded to the PRAMS survey in Spanish and for breastfeeding initiation among women who delivered very low birthweight and very preterm infants. The validity and reliability of the PRAMS data for measures assessed were high. Our findings support the use of PRAMS data for epidemiological surveillance, research, and planning.