SECTION 2: MEASUREMENT Vital Records for Quality Improvement

The birth certificate and death certificate are important sources of population-based data for assessing the extent of risk and the quality of perinatal outcome. The birth certificate contains the hospital of birth and many items, such as birth weight and race, that can serve as important risk adjusters for neonatal mortality. To assess mortality a second vital record, the death certificate, must be linked to the birth certificate. If the analysis is to be stratified by level of neonatal care or other hospital characteristics, a third file providing these details must also be utilized. The exact vital record formats, recording protocols, and quality control efforts are determined by and differ across each state. Even with these differences, the quality and completeness of vital records and their linkage are reasonable for populationbased analyses. Although the most important vital outcome from a neonatologist’s perspective is neonatal mortality, vital records can also be used to assess fetal, perinatal, postneonatal, and infant mortality. The analytic paradigm that is used in quality analysis performed on data derived from the vital record states that observed outcome is a function of risk, chance, and care. Risk is a characteristic or condition such as low birth weight or low 1-minute Apgar score that elevates the probability of an adverse outcome but is beyond the control of the agent responsible for the outcome. Using risk matrices or regression analysis one determines the expected mortality for a specific institution’s case-mix. This expectation is usually based on the statewide analysis of infants with a similar risk profile. A standardized mortality ratio is calculated by dividing observed by expected mortality. A hospital with a high observed mortality (12 deaths per 1000) and an even higher expected mortality based on the risk characteristics of its neonates (24 per 1000) would have a standardized mortality ratio of 0.5. Once the effects of chance have been accounted for by statistical testing this finding could indicate that mortality in this hospital is 50% lower then expected. Although initially intended for legal and broad-based public health purposes, vital records represent an important source of data to inform perinatal quality improvement activities. The optimal usefulness of information derived from vital records requires that clinicians take an active role in assuring that data entry is complete and accurately reflects risk status, clinical factors, and outcomes. However, even a superb database will be of limited usefulness unless it is linked to an initiative that actively involves clinicians committed to quality improvement. Pediatrics 1999;103:278–290; vital records, birth certificate, death certificate, neonatal mortality, risk adjustment, perinatal outcomes. ABBREVIATIONS. NICU, neonatal intensive care unit; PPO, preferred provider organization; EBC, electronic birth certificate; NMR, neonatal mortality rate; VLBW, very low birth weight; PNMR, postneonatal mortality rate; SMR, standardized mortality ratio; NFIMR, National Fetal Infant Mortality Review Program. The birth certificate and death certificate are an important source of population-based data for assessing the extent of risk and the quality of perinatal outcome. In addition to legal and administrative uses, the 1998 revision added many items to obtain information on demographic, behavioral, and medical factors that influence the outcome of pregnancy.1,2 A primary intention of this expansion was to gain a broader understanding of the source of socioeconomic and racial/ethnic disparities and to shed light on the relative lack of progress in reducing low birth weight and prematurely. Fortunately these factors could also be used for risk adjustment opening up the possibility of assessing the quality of perinatal care provided in a state’s delivery hospitals. Guiding these analyses is the basic paradigm; observed outcome is dependent on risk, chance, and care. If our database has items that can adequately adjust for those differences in risk that are not under the practitioner’s control and if our statistical techniques can reduce misinterpretation due to random fluctuations in outcome, the differences in outcome observed across institutions can be attributed to the quality of care provided. The purpose of this article is to examine the extent to which these requirements can be satisfactorily met and to illustrate several examples of quality analysis based on the linked birth and death certificate. Although the birth certificate has a number of items that could be used to assess the quality of perinatal care, the focus of this article will be on the use of vital records to estimate facility specific, risk-adjusted mortality rates. The birth certificate contains many items, such as birth weight and race, that are important risk adjusters. To assess mortality a second vital record, the death certificate, must be linked to the birth certificate. The resulting linked birth certificate-death certificate cohort file3 for all births during a calendar year is used to perform quality analysis. If the evaluation includes an analysis for specific levels of care (for example, the risk-adjusted mortality of a regional neonatal intensive care unit [NICU] compared with From the University of California, Berkeley, Berkeley, California. Received for publication Sep 9, 1998; accepted Sep 9, 1998. Address correspondence to Jeffrey B. Gould, MD, MPH, University of California, Berkeley, School of Public Health, 309 Warren Hall #7360, Berke-