Perinatal periods of risk: analytic preparation and phase 1 analytic methods for investigating feto-infant mortality

The Perinatal Periods of Risk (PPOR) methods provide the necessary framework and tools for large urban communities to investigate feto-infant mortality problems. Adapted from the Periods of Risk model developed by Dr. Brian McCarthy, the six-stage PPOR approach includes epidemiologic methods to be used in conjunction with community planning processes. Stage 2 of the PPOR approach has three major analytic parts: Analytic Preparation, which involves acquiring, preparing, and assessing vital records files; Phase 1 Analysis, which identifies local opportunity gaps; and Phase 2 Analyses, which investigate the opportunity gaps to determine likely causes of feto-infant mortality and to suggest appropriate actions. This article describes the first two analytic parts of PPOR, including methods, innovative aspects, rationale, limitations, and a community example. In Analytic Preparation, study files are acquired and prepared and data quality is assessed. In Phase 1 Analysis, feto-infant mortality is estimated for four distinct perinatal risk periods defined by both birthweight and age at death. These mutually exclusive risk periods are labeled Maternal Health and Prematurity, Maternal Care, Newborn Care, and Infant Health to suggest primary areas of prevention. Disparities within the study community are identified by comparing geographic areas, subpopulations, and time periods. Excess mortality numbers and rates are estimated by comparing the study population to an optimal reference population. This excess mortality is described as the opportunity gap because it indicates where communities have the potential to make improvement.