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Biomedical subjects

J B Gould

Publications and source records attributed to J B Gould.

At least 19 recordsLinked to original sources

Operational research on perinatal epidemiology, care and outcomes.

Traditionally, neonatal-perinatal medicine has been concerned with two areas of research: basic and translational. A third area, perinatal epidemiology/health outcomes research addresses those factors that impede and promote the clinical actualization of the advances developed by basic and translational research. Unfortunately, research and training in perinatal epidemiology and outcomes analysis have not kept pace with our need to understand the interplay between risk, intervention, structure and outcome. This knowledge is essential to the development of the clinical/organizational and training strategies that will enable perinatal medicine to fully realize the promise of basic and translational research.

Biomedical Research↗

Mortality and time to death in very low birth weight infants: California, 1987 and 1993.

BACKGROUND: Recent advances in perinatal technology have dramatically increased the survival of very low birth weight (VLBW) infants (<1500 g). The possibility that these advances may also prolong the time to death and increase pain and suffering has been of concern, but there have been no population-based evaluations of this issue. METHODS: Infant, neonatal, and postneonatal mortality rates and time to death for infants 500 to 749 g, 750 to 999 g, 1000 to 1499 g, and all VLBW infants born during 1987 were compared with those outcomes for infants born in 1993 using statewide California linked birth/death cohort files. To assess the effects of improved survival and changes in time until death, we calculated the total days of life preceding an infant death per 1000 live born infants (TDD). RESULTS: VLBW infants comprised.96% of California's live births in 1987 and.92% of those in 1993. Between 1987 and 1993, VLBW infant mortality rate decreased 28.4% (from 290.7 to 208.3 per 1000 live born VLBW infants), VLBW neonatal mortality rate decreased 30. 3% (from 244.5 to 170.4), and VLBW postneonatal mortality rate decreased 25.3% (from 61.2 to 45.7 per 1000 VLBW alive at 28 days; P <.05 for each rate). Infant mortality rates decreased by 18.8% (718. 1 to 583.0 per 1000) for infants 500 to 749 g, 43.3% (375.1 to 202. 6) for infants 750 to 999 g, and 40.1% (127.9 to 76.7) for infants 1000 to 1449 g (P <.05 for each group). Neonatal mortality and postneonatal mortality rates also decreased in all 3 VLBW subgroups. These reductions in mortality rates were not accompanied by a significant difference in the distribution of times to death or a significant increase in the average time to death for all VLBW infants (22.0 vs 23.6 days) or for those with birth weights of 500 to 749 g (12.7 vs 71.5 days). Reduced mortality in larger infants was accompanied by an increase in the average time to death, from 24. 3 to 32.5 days in infants 750 to 999 g and from 32.3 to 47.0 days in infants 1000 to 1449 g. TDD decreased from 6410 to 4908 days for all VLBW infants. TDD was also reduced 26.4% (2401 days), 24.3% (2115 days), and 22.5% (1043 days) for the 3 VLBW birth weight groups. CONCLUSIONS: Both mortality rate and timing of death are important when assessing the impact of advances in perinatal technology. Although the average time to death was significantly increased in VLBW infants weighing >750 g, between 1987 and 1993, advances in perinatal technology dramatically decreased VLBW mortality. In the State of California in 1993, this resulted in 452 fewer VLBW deaths and 8233 fewer days preceding a VLBW death than expected.

California↗

Newborn discharge timing and readmissions: California, 1992-1995.

CONTEXT: Hospital stays for newborns and their mothers after uncomplicated vaginal delivery have decreased from an average of 4 days in 1970 to 1.1 days in 1995. Despite the lack of population-based research on the quality-of-care implications of this trend, federal legislation passed in 1996 mandated coverage for 48-hour hospital stays after uncomplicated vaginal delivery. OBJECTIVE: To assess the impact of very early discharge (defined as discharge on the day of birth) on the risk of infant readmission during the neonatal period in a California healthy newborn population. DESIGN: Retrospective cohort study, based on a linked dataset consisting of the birth certificate, newborn, and maternal hospitalization record, and linked infant readmission records for all healthy, vaginally delivered, and routinely discharged California newborns from 1992 to 1995. OUTCOME MEASURES: Very early discharge and infant readmission during the first 28 days of life. RESULTS: The percentage of infants discharged very early or early (after a 1-night stay) increased from 71% in 1992 to 85% in 1995. The percentage of infants discharged very early increased from 5.0% in 1992 to 5.7% in 1993 and 7.0% in 1994, then decreased to 6.7% in 1995. Characteristics that have been previously associated with suboptimal pregnancy outcomes were found to decrease the likelihood of very early discharge, eg, maternal complications, primiparity, and Hispanic, African American, South East Asian, or other Asian race/ethnicity. The rate of readmission in the neonatal period initially decreased from 27.6 infants per 1000 in 1992 to 25.67 infants per 1000 in 1994, then increased to 30.2 infants per 1000 in 1995. For infants discharged early, no statistically significant increase in the risk of readmission was observed, compared with infants discharged after a 2+-night stay. The adjusted odds ratio (OR) for readmission was statistically significantly higher for infants who were discharged very early, compared with infants discharged early (OR: 1.27), first order births (OR: 1.21), infants born to mothers who experienced complications (OR: 1.11), infants with Medicaid insurance (OR: 1.23), and infants born to mothers who received adequate plus prenatal care (OR: 1.15). The risk was statistically significantly lower for female infants (OR: 0.75). The proportion of infants rehospitalized for dehydration and low-risk infections over the 4 study years combined was statistically significantly higher in infants discharged very early (4.37 per thousand and 10.30 per thousand, respectively), compared with infants discharged early (3.59 per thousand and 8.16 per thousand, respectively) or after a 2+-night stay (2.91 per thousand and 7.95 per thousand, respectively). The proportion of infants rehospitalized for dehydration increased statistically significantly from 2.89 per thousand in 1992 to 4.52 per thousand in 1995. CONCLUSIONS: One-night stays with adequate antenatal and postnatal care outside the hospital do not increase the risk of readmission for healthy, vaginally delivered infants born in California. However, the decision to discharge infants on the day of birth should be applied conservatively because of the increased risk of infant readmission associated with very early discharge.

California↗

Preventing early-onset group B streptococcal sepsis: strategy development using decision analysis.

OBJECTIVE: To evaluate recommended strategies for prevention of early-onset group B streptococcal infections (EOGBS) with reference to strategies optimized using decision analysis. METHODS: The EOGBS attack rate, prevalence and odds ratios for risk factors, and expected effects of prophylaxis were estimated from published data. Population subgroups were defined by gestational age, presence or absence of intrapartum fever or prolonged rupture of membranes, and presence or absence of maternal group B streptococcus (GBS) colonization. The EOGBS prevalence in each subgroup was estimated using decision analysis. The number of EOGBS cases prevented by an intervention was estimated as the product of the expected reduction in attack rate and the number of expected cases in each group selected for treatment. For each strategy, the number of residual EOGBS cases, cost, and numbers of treated patients were calculated based on the composition of the prophylaxis group. Integrated obstetrical-neonatal strategies for EOGBS prevention were developed by targeting the subgroups expected to benefit most from intervention. RESULTS: Reductions in EOGBS rates predicted by this decision analysis were smaller than those previously estimated for the strategies proposed by the American Academy of Pediatrics in 1992 (32.9% vs 90.7%), the American College of Obstetricians and Gynecologists in 1992 (53.8% vs 88.8%), and the Centers for Disease Control and Prevention in 1996 (75.1% vs 86.0%). Strategies based on screening for GBS colonization with rectovaginal cultures at 36 weeks or on use of a rapid test to screen for GBS colonization on presentation for delivery, combining intrapartum prophylaxis for selected mothers and postpartum prophylaxis for some of their infants, would require treatment of fewer patients and prevent more cases (78.4% or 80.1%, respectively) at lower cost. CONCLUSIONS: No strategy can prevent all EOGBS cases, but the attack rate can be reduced at a cost <$12 000 per prevented case. Supplementing intrapartum prophylaxis with postpartum ampicillin in a few infants is more effective and less costly than providing intrapartum prophylaxis for more mothers. Better intrapartum screening tests offer the greatest promise for increasing efficacy. Integrated obstetrical and neonatal regimens appropriate to the population served should be adopted by each obstetrical service. Surveillance of costs, complications, and benefits will be essential to guide continued iterative improvement of these strategies.

Age of Onset↗

Risk factors for early-onset group B streptococcal sepsis: estimation of odds ratios by critical literature review.

OBJECTIVE: To identify and to establish the prevalence of ORs factors associated with increased risk for early-onset group B streptococcal (EOGBS) infection in neonates. streptococcal (EOGBS) infection in neonates. STUDY DESIGN: Literature review and reanalysis of published data. RESULTS: Risk factors for EOGBS infection include group B streptococcal (GBS)-positive vaginal culture at delivery (OR: 204), GBS-positive rectovaginal culture at 28 (OR: 9.64) or 36 weeks gestation (OR: 26. 7), vaginal Strep B OIA test positive at delivery (OR: 15.4), birth weight </= 2500 g (OR: 7.37), gestation <37 weeks (OR: 4.83), gestation <28 weeks (OR: 21.7), prolonged rupture of membranes (PROM) >18 hours (OR: 7.28), intrapartum fever >37.5 degrees C (OR: 4.05), intrapartum fever, PROM, or prematurity (OR: 9.74), intrapartum fever or PROM at term (OR: 11.5), chorioamnionitis (OR: 6.43). Chorioamnionitis is reported in most (88%) cases in which neonatal infection occurred despite intrapartum maternal antibiotic therapy. ORs could not be estimated for maternal GBS bacteriuria during pregnancy, with preterm premature rupture of membranes, or with a sibling or twin with invasive GBS disease, but these findings seem to be associated with a very high risk. Multiple gestation is not an independent risk factor for GBS infection. CONCLUSIONS: h Mothers with GBS bacteriuria during pregnancy, with another child with GBS disease, or with chorioamnionitis should receive empirical intrapartum antibiotic treatment. Their infants should have complete diagnostic evaluations and receive empirical treatment until infection is excluded by observation and negative cultures because of their particularly high risk for EOGBS infection. Either screening with cultures at 28 weeks gestation or identification of clinical risk factors, ie, PROM, intrapartum fever, or prematurity, may identify parturients whose infants include 65% of those with EOGBS infection. Intrapartum screening using the Strep B OIA rapid test identifies more at-risk infants (75%) than any other method. These risk identifiers may permit judicious selection of patients for prophylactic interventions.

Age of Onset↗

Antimicrobial prevention of early-onset group B streptococcal sepsis: estimates of risk reduction based on a critical literature review.

OBJECTIVE: To identify interventions that reduce the attack rate for early-onset group B streptococcal (GBS) sepsis in neonates. STUDY DESIGN: Literature review and reanalysis of published data. RESULTS: The rate of early-onset GBS sepsis in high-risk neonates can be reduced by administration of antibiotics. Treatment during pregnancy (antepartum prophylaxis) fails to reduce maternal GBS colonization at delivery. With the administration of intravenous ampicillin, the risk of early-onset infection in infants born to women with preterm premature rupture of membranes is reduced by 56% and the risk of GBS infection is reduced by 36%; addition of gentamicin may increase the efficacy of ampicillin. Treatment of women with chorioamnionitis with ampicillin and gentamicin during labor reduces the likelihood of neonatal sepsis by 82% and reduces the likelihood of GBS infection by 86%. Universal administration of penicillin to neonates shortly after birth (postpartum prophylaxis) reduces the early-onset GBS attack rate by 68% but is associated with a 40% increase in overall mortality and therefore is contraindicated. Intrapartum prophylaxis, alone or combined with postnatal prophylaxis for the infants, reduces the early-onset GBS attack rate by 80% or 95%, respectively. CONCLUSIONS: Women with chorioamnionitis or premature rupture of membranes and their infants should be treated with intravenous ampicillin and gentamicin. Intrapartum antimicrobial prophylaxis may be appropriate for other women whose infants are at increased but less extreme risk, and supplemental postpartum prophylaxis may be indicated for some of their infants. Selection of appropriate candidates and prophylaxis strategies requires careful consideration of costs and benefits for each patient. group B streptococcus, neonatal sepsis, early-onset sepsis, prevention, prophylaxis.

Age of Onset↗

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 population-based 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.

Birth Certificates↗

Socioeconomic status, neighborhood social conditions, and neural tube defects.

OBJECTIVES: This study evaluated the contributions of lower socioeconomic status (SES) and neighborhood socioeconomic characteristics to neural tube defect etiology. The influence of additional factors, including periconceptional multivitamin use and race/ethnicity, was also explored. METHODS: Data derived from a case-control study of California pregnancies from 1989 to 1991. Mothers of 538 (87.8% of eligible) case infants/fetuses with neural tube defects and mothers of 539 (88.2%) nonmalformed infants were interviewed about their SES. Reported addresses were linked to 1990 US census information to characterize neighborhoods. RESULTS: Twofold elevated risks were observed for several SES indicators. Risks were somewhat confounded by vitamin use, race/ethnicity, age, body mass index, and fever but remained elevated after adjustment. A risk gradient was seen with increasing number of lower SES indicators. Women with 1 to 3 and 4 to 6 lower SES indicators had adjusted odds ratios of 1.6 (1.1-2.2) and 3.2 (1.9-5.4), respectively, compared with women with no lower SES indicators. CONCLUSIONS: Both lower SES and residence in a SES-lower neighborhood increased the risk of an neural tube defect-affected pregnancy, with risks increasing across a gradient of SES indicators.

Adult↗

Vital statistics linked birth/infant death and hospital discharge record linkage for epidemiological studies.

A methodology for linking vital statistics linked birth/death data and hospital discharge data is described. The resulting data set combines information on a neonate's sociodemographic characteristics, prenatal care, and mortality aspects and connects it to detailed health outcome and resource utilization data, thus establishing an extensive database for epidemiological studies. In the absence of a universal identifier common to both databases, our linkage strategy relied on using a virtual identifier based on variables common to both data sets. In the case of multiple incidences of the same virtual identifier we used secondary health status information to optimize the likelihood of linking low birth weight or premature infants in one database to infants of similar health status in the other while randomizing cases in which no secondary information was present. Applying our method to the 1992 California birth cohort, we could link 563,114 out of 571,189 eligible births (98.59%). Of these links, 91.2% were established on the basis of unique virtual identifiers. The link was internally consistent and no bias was evident when comparing variable distributions for all single live births in the vital statistics linked birth/death file and linked births in the linked vital statistics linked birth/death and hospital discharge file. Multiple imputation techniques showed that the prediction error incurred by randomization was negligible. Even though computationally intensive, our method for linking the vital statistics linked birth/death file and the hospital discharge file appeared to be effective. However, it is important to be aware of the limitations of the resulting data set, in particular the fact that it cannot be used for tracking individual cases. The method provides a database suitable for a variety of perinatal epidemiological analyses, such as descriptive studies of disease distribution in neonates, studies of the geographic distribution of disease, and studies of the relationship between risk and outcome.

Algorithms↗

Racial disparities in outcomes of military and civilian births in California.

OBJECTIVE: To examine racial disparities in prenatal care utilization, birth weight, and fetal and neonatal mortality in a population for whom financial barriers to health care services are minimal. STUDY-DESIGN: Using linked birth, fetal death, and infant death certificate files, we examined prenatal care utilization, birth weight distribution, and fetal and neonatal mortality rates for all white and black births occurring in military hospitals in California from January 1, 1981, to December 31, 1985. These patterns were compared with the experience of their civilian counterparts during the same time period. RESULTS: Black mothers had higher percentages of births occurring in teenaged and unmarried mothers than did white mothers in military and civilian populations. First-trimester prenatal care initiation was lower for blacks in the military (relative risk, 0.79; 95% confidence interval, 0.75-0.82) and civilian (relative risk, 0.51; 95% confidence interval, 0.50-0.52) populations. However, the scale of the disparity in prenatal care utilization was significantly smaller (P < .001) in the military group. Rates of low birth weight and fetal and neonatal mortality among blacks were elevated in the military and civilian groups. However, the racial disparity in low birth weight was significantly smaller in the military group (P < .01 and P < .001, respectively). CONCLUSIONS: In populations with decreased financial barriers to health care, racial disparities in prenatal care use and low birth weight were reduced. However, the persistence of significant disparities suggests that more comprehensive strategies will be required to ensure equity in birth and neonatal outcome.

California↗

Database use in neonatal intensive care units: success or failure.

The purpose of this national survey was to define the extent and features of database use by 445 tertiary level neonatal intensive care nurseries in the United States. Of the 305 centers responding to our survey, 78% had a database in use in 1989 and 15% planned to develop one in the future. Nurseries varied remarkably in the volume of data collected, the amount of time devoted to completing data collection forms, and the personnel involved in data collection. Although data were used primarily for statistical reports (93% of nurseries), quality assurance (73%) and research activities (61%) were also enhanced by database information. Neonatal databases were used to generate reports for the permanent medical record in 38% of centers. Satisfaction with the database was dependent on how useful the database information was to centers which collected and actually used a large volume of information. Overall, nurseries expressed a high degree of confidence in the data they collected, and 65% felt their neonatal database information could be used directly in publication of research. It was disturbing that accuracy of data was not monitored formally by the majority of nurseries. Only 27% of centers followed a routine schedule of data quality assurance, and only 53% had built in error messages for data entry. We caution all who receive database information in the form of morbidity and mortality statistics, clinical reports on patients cared for in neonatal units, and published manuscripts to be attentive to the quality of the data they consume. We feel that future database design efforts need to better address data quality control. Our findings stress the importance and need for immediate efforts to better address database quality control.

Data Collection↗

Young people's perception of the space shuttle disaster: case study.

To explore how young people were affected by the space shuttle disaster, the responses of 79 females in 5th, 8th, and 12th grades and 18 males in 5th grade who had witnessed the event on video at school were examined. Six days after the Challenger accident, they were asked to list and rank the three things that had affected them most over the last seven days and to explain the reason behind their first choice. Only 8.9% of the females ranked the space shuttle first, and only 30.4% ranked it in the top three. Competing issues were school-related activities, grades, and family relations. Of the 5th-grade males, 88.9% mentioned the space shuttle and 38.9% saw it as their top concern. For both males and females, this choice was based on sadness and empathy. The youths did not relate the disaster to the fragility of modern technology or the threat of nuclear war. The relatively low response rate of the females who had witnessed this event was interpreted as being indicative of repression-denial. It was concluded that future research should address the extent to which post-crisis denial could be masking more significant psychological trauma in youth.

Adolescent↗

Generational differences in perinatal health among the Mexican American population: findings from HHANES 1982-84.

Data from the Hispanic Health and Nutrition Examination Survey (HHANES) were used to examine a profile of social, medical, and behavioral characteristics associated with low birth-weight (LBW) and miscarriages in first and second generation Hispanics of Mexican descent. The percentage of LBW was 5.3 and of miscarriages was 12.7. LBW rates were higher for second generation primipara and multipara compared with first generation women. Using multivariate logistic regression techniques and adjusting for complex design effects, generation was found to be a significant predictor of LBW but not of miscarriages. The findings support existing evidence that a Mexican cultural orientation protects first generation. Mexico-born women against a risk for LBW. However, the findings do not show significant effects of generation on miscarriages, suggesting that cultural effects are not consistent for all pregnancy outcomes. Furthermore, we suggest that the higher rates of LBW in second generation women are not due to a higher rate of miscarriages as has been hypothesized.

Abortion, Spontaneous↗

Socioeconomic differences in rates of cesarean section.

Increasing cesarean-section rates have focused attention on variations in the use of this procedure that appear to be independent of medical indication. We investigated the relation between the rate of primary cesarean section and socioeconomic status in a cohort of 245,854 singleton infants born to non-Hispanic white, black, Asian-American, and Mexican-American residents of Los Angeles County, California. On the basis of birth-certificate data for 1982 and 1983, a significant relation, independent of maternal age, parity, or birth weight, was found between the rates of primary cesarean section and socioeconomic status. Women who lived in census tracts with a median family income of more than $30,000 had a primary cesarean-section rate of 22.9 percent, as compared with 13.2 percent among women residing in areas with a median family income under $11,000. In women between the ages of 18 and 34, the incidence of reported complications of pregnancy or childbirth in the lowest-income group was 10.9 percent, as compared with 17.4 percent in the highest-income group (accounting for 42 percent of the difference in the rate of primary cesarean section between groups); the rate of primary cesarean section in the presence of complications in these two groups was 65.4 percent and 79.3 percent (accounting for 17 percent of the difference); and the primary rate in the absence of reported complications in these two groups was 6.4 percent and 10.5 percent (accounting for 41 percent of the difference). The rates of primary cesarean section were highest among non-Hispanic whites (20.6 percent), intermediate among Asian Americans (19.2 percent) and blacks (18.9 percent), and lowest among Mexican Americans (13.9 percent). Significant socioeconomic differences in these rates were observed in all four groups (P less than 0.01). We conclude that the rates of primary cesarean section vary directly with socioeconomic status and that this association cannot be accounted for by differences in maternal age, parity, birth weight, race, ethnic group, or complications of pregnancy or childbirth.

Adolescent↗

Socioeconomic differentials and neonatal mortality: racial comparison of California singletons.

The median family income of the zip code of maternal residence was used to estimate the presence and determine the extent of socioeconomic differentials in the neonatal mortality rates of a cohort of 401,399 white and of 66,577 black Californian singletons born from 1982 to 1983. The neonatal mortality rate in the white infants increased from 3.99 in mothers residing in zip codes with a median family income greater than $25,000 to 12.1 for mothers residing in zip codes with a median family income less than $11,000. With decreasing socioeconomic status there was also a significant increase in the percentage of white infants weighing less than 2,500 g (percentage of low birth weight increased from 3.75 to 8.33) and weighing less than 1,500 g (percentage of very low birth weight increased from 0.56 to 1.46). When the source of the socioeconomic difference in white neonatal mortality was partitioned, 77.4% was due to deterioration in the birth weight distribution and 22.6% to deterioration in the birth weight-specific mortality rates. For the black cohort, the neonatal mortality rate increased from 5.9 in the most, to 9.0 in the least affluent strata. Although decreasing residential median family income was associated with an increase in the percent low birth weight (8.19 v 12.86), the percentage of very low birth weight was not significantly different (1.59 v 2.10). When the source of the differential in black neonatal mortality was partitioned, only 29% was due to deterioration of the birth weight distribution, whereas 71% was secondary to less favorable birth weight-specific mortality rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗

The relationship between sleep and sudden infant death.

Infants epidemiologically at high risk for SIDS demonstrate a variety of abnormalities in sleep-state organization, maturation, and sleep-state modulation of cardio-respiratory control mechanisms. These involve both the REM and quiet-sleep states and are seen in twins who have had no evidence of clinical cardio-respiratory compromise during infancy as well as in near-miss infants who have suffered serious cardio-respiratory failure. Although these infants have higher levels of REM sleep around 40 weeks, of special concern is the decrease in the maturation of the quiet system, which becomes evident after 44 weeks, and the reported quiet-sleep abnormalities in reflex control of respiration and arousal. The source of these abnormalities is environmental rather than genetic and most likely occurs prenatally. During the critical period for SIDS, infant sleep begins to coalesce from a series of naps to more prolonged night time sleep periods that last up to 8 hours. We believe that the ability to maintain physiologic homeostasis during prolonged sleep is a challenge facing infants who are epidemiologically at risk for sudden infant death. The challenge facing sleep research is the more complete understanding of the relationship between prolonged inhibition, homeostasis, arousal, and development.

Diseases in Twins↗

Improving perinatal outcome through data management: the design of the small area analysis system.

The decentralization of health management requires that appropriate tools be developed for decision support at the local level. The Improved Pregnancy Outcome Data Management System (IPODM) was designed to enable health managers and physicians with little computer experience to access over 500 variables derived from United States Census and California Vital Statistics sources. Using an interactive format one can create datasets describing the sociodemographic composition and perinatal outcome of individuals residing in individual census tracts (or zip codes) and in aggregates of these basic units such as neighborhoods, health catchment areas, or municipal districts. IPODM allows one to analyze this information in terms of tables, plots, maps, and basic statistical procedures using an interactive format. This paper describes the system designed for the State of California and the principles that guided the design.

Database Management Systems↗

Socioeconomic status and low birth weight: a racial comparison.

The relationships between socioeconomic status, low birth weight, births to teenagers, and inadequate prenatal care were compared among white and black infants. A cohort of 127,558 singleton births, born from 1982 to 1983 in Los Angeles County, California, was evaluated. Socioeconomic status was estimated by the 1979 median family income of the census tract of maternal residence. For both racial groups the deterioration of residential area socioeconomic status was associated with a significant increase in the percentage of high-risk teenage mothers (less than 17 years of age), in the percentage of mothers with either no, only third trimester, or unknown prenatal care, and in the percentage of low birth weight infants. The rate of increase in the percentage of low birth weight in response to the socioeconomic deterioration of residential area was similar in black and in white groups. There was, however, a racial gap of 5% low birth weight that remained constant across all income areas. At the individual level, there were marked racial differences in the relative risks imposed by one's residential median family income, age, prenatal care, and pattern of interactions.

Adolescent↗