Statistical estimation of child abuse rates from administrative databases

Increasingly, child welfare agencies need to provide statistical summary re ports on the safety of the children for whom they are responsible. Often th ese summaries include ordinary period rates of child abuse derived from adm inistrative data. These indices fail to adjust for the length of exposure t o risk, such as time in foster care during the year. Since duration of care often differs by living arrangement, race, gender, and other variables, th e use of such period rates to measure child safety or abuse may bias compar isons over time or across groups. This bias may lead to misperceptions of t rends in safety over time, and of the comparative safety of different modes of care. This article discusses fundamental issues in the extraction, from administrative data, of valid measures of child welfare outcomes targeted to specific populations. In addition, it provides an introduction to exposu re adjustment of child welfare measures based on information that is genera lly readily available in administrative databases. Cohort-based incidence d ensity rates are recommended in preference to period prevalence fi om cross -sectional data. Survival modeling/multiple event history analysis is descr ibed for more complex situations. The ready availability of such analytic t ools suggests further directions for quantitative research in child welfare monitoring.