Search PubMed⌕ Search

Biomedical subjects

G R Alexander

Publications and source records attributed to G R Alexander.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Gestational age reporting and preterm delivery.

This study examines recent trends in the reporting completeness and quality of gestational age estimates derived from the date of the last normal menses (DLNM) as reported in South Carolina vital records from 1974 to 1985. Noteworthy improvements in the completeness of reporting emerged during this period with a decline from 31.1 percent missing information in 1974 to 6.6 percent missing in 1985. Completeness of reporting and strategies for imputing values for missing data were analyzed for their impact on the calculation of the percentage of preterm live births. The results indicate that the underreporting of gestational age can lead to marked underestimation of the preterm percentage in a population and to misinterpretation of trends in these percentages. Based on the results of this analysis, it is recommended that preterm percentages be based on cases with DLNM gestational age values between 20 and 50 weeks. Since cases with missing or implausible gestational age data have a greater risk of a poor pregnancy outcome, these findings emphasize the importance of identifying both the completeness of data reporting and the use of imputation and deletion strategies when employing population-based DLNM data to calculate gestational age related indicators.

Adolescent↗
PubMedDate not supplied

Prenatal care utilization: its measurement and relationship to pregnancy outcome.

This study proposes a redesigned measure of prenatal care utilization based on modifications made to a preexisting index of the adequacy of such care. Six prenatal care utilization groups were delineated: intensive, adequate, intermediate, inadequate, no-care, and missing/unknown. Using 430,349 cases from South Carolina and North Carolina vital records from 1978 to 1982 (live birth-infant death cohort files for white resident mothers), this proposed prenatal care utilization measure was examined by maternal sociomedical risk characteristics (age-parity, marital status, education, complications of pregnancy, and previous pregnancy terminations) and by pregnancy outcomes (birth weight, gestational age, and birth weight- and gestational age-specific neonatal mortality). The intensive prenatal care group had relatively more pregnancy complications but also the most preferred pregnancy outcomes. Appreciable differences in birth weight and gestational age distributions were observed among the prenatal care categories within maternal risk status groups. Increased utilization of prenatal care was associated with higher mean birth weight and gestational age. However, after controlling for maternal risk status, an appreciable variation in birth weight- and gestational age-specific neonatal mortality was not apparent across prenatal care groups.

Adolescent↗
PubMedDate not supplied

Racial disparities in pregnancy outcomes: the role of prenatal care utilization and maternal risk status.

Distinct black-white differences in pregnancy outcome and prenatal care utilization have been a persistent feature of U.S. natality-related statistics. Using South Carolina and North Carolina live birth-infant death cohort files for 1978-1982, this study examines the extent to which variations in prenatal care utilization may be associated with racial disparities in pregnancy outcome within maternal sociomedical risk groups. After taking indicators of maternal risk into account (age-parity, education, marital status, complications of pregnancy and previous pregnancy terminations), birth weight and gestational age distributions and birth weight- and gestational age-specific neonatal mortality rates of blacks and whites were compared by level of prenatal care utilization. Distinct racial differences in birth weight and gestational age distributions were observed within equivalent maternal risk and prenatal care categories, with whites having an approximately 200-gram mean birth weight and five-day mean gestational age advantage compared to blacks. In this analysis of more than 650,000 cases, low-risk blacks adequately utilizing prenatal care had a lower mean birth weight (3,266 grams) and a higher neonatal mortality rate (6.6) than low-risk, inadequate-care whites (3,302 grams; 6.1).

Black or African American↗
PubMedDate not supplied

Racial differences in the relation of birth weight and gestational age to neonatal mortality.

Utilizing South Carolina live birth-infant death cohort files for the period 1975-80, this study examines the bivariate distribution of birth weight-gestational age (BW-GA), intrauterine growth curves, and BW-GA specific neonatal mortality rates (NMRs) by race. Comparison of BW-GA distributions revealed an appreciable shift between racial subgroups. Nonwhites, on the average, were born 1 week earlier and 270 grams lighter in weight than whites. In addition to racial differences in rates of intrauterine growth, nonwhites experienced lower BW-GA NMRs than whites in BW-GA categories less than 3,000 grams and less than 38 weeks. However, the improved mortality experience of nonwhites at more immature BW-GA categories was not consistently present when different cause-specific NMRs were considered. These persistent racial variations highlight continuing issues regarding both the use of a single norm for defining low birth weight or prematurity and the role of nonsocioeconomic factors related to racial BW-GA distribution and mortality disparities. As birth weight and gestational age represent empirical indicators of the maturity and survivability of an infant at birth, these data and previous supporting research raise further concerns regarding the ability of these indicators to accurately reflect equivalent fetal development and subsequent risk of mortality among racial groups.

Birth Weight↗
PubMedDate not supplied

Occupational health services in South Carolina manufacturing plants: results of a survey.

A mailed survey of occupational health and safety practices in industrial manufacturing plants with more than 50 employees was carried out in South Carolina, with a response rate of 60 percent. The responding plants represented 73 percent of the total workforce in the industries. Data were analyzed in relation to the types of industry as delineated by the Standard Industrial Code. Eighty-three percent of the responding plants (a percentage that represented more than 92 percent of the total workforce in the industries) had some arrangements for the medical or nursing care of employees. For the study, occupational health services were defined at three levels: basic (mandatory), secondary (beneficial to management), and tertiary (health promotion-preventive medicine). The basic services provided by most of the industries surveyed appeared to be adequate. Secondary services were well developed except in the apparel and lumber industries. Tertiary services, in terms of five selected preventive programs, were moderately developed only in the paper, petroleum, and chemical industries. Only alcohol abuse control programs were commonly offered in the other types of industry. The size of the workforce in a plant partly dictated the level of occupational health services it offered but did not always account for all inter-industry variation.

Health Promotion↗
PubMedDate not supplied

South Carolina's suicide mortality in the 1970s.

In an epidemiologic study of suicide mortality among South Carolina residents for the years 1970--78, death certificates for 2,763 persons were reviewed. The overall suicide rates were lower than those observed in the same period for the United States. As expected, the highest rates were among white males; females and nonwhite males had rates with intermediate values, and nonwhite females, the lowest rates. Rates for white males increased up to age 75. All other race-sex groups peaked at much younger ages. An increase in suicide rates over time appeared in those under 25 years, and a slight decline was observed in residents aged 50--74. Age-race-sex-adjusted rates proved relatively stable over the 9 years. Geographically, race-adjusted rates by county varied from calculated expected values, with some suggestion of a pattern for the counties with the highest rates. However, no urban-rural differences were seen. Examination of methods used to commit suicide reveals that firearms were the most common means in all race-sex groups, accounting for 78.7 percent of deaths. The percentage of firearm users was almost identical among white males and white females, differing markedly from the country as a whole. Females of both race groups were more likely to have used poisons than males, but the percentage of those who used poisons was much less than would be expected from national data. This study confirms previous findings of sex and race differentials, rate changes with age, increasing rates in young people, and lower overall rates in the Southeast compared with the entire country. Interpretation of race-sex specific rates, together with suicide methods, lends support to the assertion that suicide rates are independent of methods. Rate trends by age groups over time are believed to have important implications.

Adolescent↗
PubMedDate not supplied

Determinants of prenatal care use in Hawaii: implications for health promotion.

This study examines the association between maternal sociodemographic characteristics and the receipt of different levels of prenatal care use (no care, inadequate, intermediate, adequate) in order to determine different patterns in the relationships between maternal characteristics and these distinct categories of prenatal care use. Using the 1979-1992 Hawaii live birth vital record file, single live births to Hawaii resident mothers of white, Hawaiian/part-Hawaiian, Filipino, or Japanese ethnicity, who did not indicate on the birth certificate that either parent was active duty military, were selected. Over one quarter of this study population did not initiate prenatal care in the first trimester. Given the high level of insurance coverage found in Hawaii, this finding is disconcerting, particularly in relation to the U.S. Year 2000 Objective of 90% initiation in the first trimester. Overall, the factors that predicted receipt of any prenatal care predicted more adequate use of prenatal care as well. Noteworthy exceptions were maternal age and ethnicity. Identifying these exceptions is important for the development of a more detailed understanding of risk factors related to use of prenatal care to better target program responses aimed at improving prenatal care use. In addition, these data suggest that removing financial barriers to access to care does not guarantee universal use of disease prevention and health promotion services.

Adolescent↗
PubMedDate not supplied

Discordance between LMP-based and clinically estimated gestational age: implications for research, programs, and policy.

This study examines the comparability between the last menstrual period-based and clinically estimated gestational age as collected on certificates of live birth. It explores whether sociodemographic or delivery characteristics influence their agreement and contrasts health status and health care utilization indicators, such as preterm, small for gestational age, and adequacy of prenatal care percentages, produced by each gestational age measure. The 1989-91 South Carolina public use live birth files were used for this analysis. A total of 169,082 single births to resident mothers were selected for investigation. The clinically estimated gestational age distribution exhibited a higher mean and a tendency toward even number digit preference. The last menstrual period-based measure produced higher preterm and postterm percentages. More than 60 percent of the last menstrual period-based preterm births were classified as preterm by the clinical estimate. The sensitivity of the clinical estimate was 27 percent for postterm births. The overall concordance (the percentage of cases with the same value for both measures) was 47 percent, but it varied considerably by gestational age. Between 30 and 35 weeks, the clinical estimate exceeded the last menstrual period-based value by 2 weeks or more for more than 40 percent of the cases. Concordance also varied by race of mother, hospital delivery size, trimester prenatal care began, and birth weight. The last menstrual period-based and the clinically estimated gestational age distributions exhibited notable dissimilarities, produced marked differences in health status indicators, and varied in concordance by gestational age and by sociodemographic, prenatal care, and hospital characteristics. These systematic differences suggest that a transition from the traditionally used last menstrual period-based measure to the clinical estimate or a composite measure will not produce uniform results across geo-political areas and at-risk groups but will be appreciably influenced by population and health care characteristics.

Birth Certificates↗
PubMedDate not supplied

Pregnancy outcomes of U.S.-born Puerto Ricans: the role of maternal nativity status.

This study examines maternal sociodemographic characteristics, prenatal care use, and birth outcomes of U.S. resident Puerto Ricans by maternal nativity status in order to ascertain if Puerto Rican-born mothers exhibit better birth outcomes than U.S.-born Puerto Rican mothers, after controlling for maternal risk characteristics. All single live births to U.S. resident mothers indicating a Puerto Rican heritage or ethnicity on the infant's Certificate of Live Birth were selected for analysis from the 1983-1986 National Center for Health Statistics' Public Use U.S. Linked Live Birth and Infant Death File. Infants of Puerto Rican-born mothers had a significantly lower risk of low birthweight and small for gestational age infants than infants of U.S.-born Puerto Rican mothers, after controlling for available maternal risk factors. Nevertheless, infants of Puerto Rican-born mothers had a significantly higher risk of neonatal mortality, although they exhibited a significantly lower risk of postneonatal mortality. No significant maternal nativity status differences in very preterm, preterm, very low birthweight, and infant mortality were identified after controlling for the same maternal sociodemographic and prenatal care use variables. Infants of Puerto Rican-born mothers demonstrated higher birthweight-specific neonatal mortality rates but lower birthweight-specific postneonatal mortality rates for nearly every birthweight category. These findings emphasize the need for further investigation of the factors that may influence maternal nativity variations in intrauterine growth retardation, access to tertiary health care services, and postneonatal mortality.

Adolescent↗
PubMedDate not supplied

Variations in pregnancy outcomes by race among 10-14-year-old mothers in the United States.

This study used the 1983-86 U.S. Linked Live Birth-Infant Death Files to examine variations in pregnancy outcomes among 38,551 U.S. resident black and white adolescents ages 10 through 14. The birth rate was 4.29 per 1,000 for blacks, more than 7 times the rate for whites (.59 per 1,000). Black mothers had higher proportions of very low and low birth weight infants than did whites (very low birth weight: 3.7 versus 2.6; low birth weight: 15.0 versus 10.5). Neonatal and infant mortality rates were higher among very low birth weight and low birth weight white infants. Neonatal and infant mortality rates were similar for normal birth weight infants of both races, but were 3.7 to 7.4 times higher among black infants with birth weights more than 4,250 grams. Logistic regression indicated that black mothers were at higher risk for having infants who were low birth weight, very low birth weight, small for gestational age, preterm, and very preterm. There were no differences by race for neonatal, postneonatal, and infant mortality. While the risk for poor pregnancy outcomes is great among young adolescents, young black adolescents appear to be particularly vulnerable. Attempts to reduce unintended pregnancies in this group should receive highest priority.

Adolescent↗
PubMedDate not supplied

Comparing mothers' reports on the content of prenatal care received with recommended national guidelines for care.

The Public Health Service's Expert Panel on the Content of Prenatal Care Report in 1989 provided detailed guidelines for the components of each prenatal visit. However, the extent to which women were receiving the recommended care when the guidelines were being formulated has yet to be determined. The 1988 National Maternal and Infant Health Survey results permit an examination of the proportion of women who reported receiving some of the recommended procedures. Women were asked if they received six of the recommended procedures (blood pressure measurement, urine test, blood test, weight and height taken, pelvic examination, and pregnancy history) in the first two visits, and whether they received seven types of advice or counseling (nutrition; vitamin use; smoking, alcohol, and drug use cessation; breastfeeding; and maternal weight gain) any time during their pregnancy. Only 56 percent of the respondents said they received all of the recommended procedures in the first two visits, and only 32 percent of the respondents said they received advice in all of the areas. Logistic regression analysis indicated that women receiving their care from private offices were significantly less likely to receive all the procedures and advice than women at publicly funded sites of care. This study suggests that recommendations of the Public Health Service's expert panel were not being met.

Chi-Square Distribution↗
PubMedDate not supplied

Determinants of meconium-stained amniotic fluid in term pregnancies.

This study examines ethnic variations in meconium-stained amniotic fluid in term pregnancies, taking into account the role of gestational age, maternal sociodemographic characteristics, and medical risk factors. The study population included black and white singleton live births (N = 14,419) between 37 and 42 weeks' gestation, delivered vaginally at the Medical University of South Carolina from 1982 through 1990. Chi-square and logistic regression analysis were used to examine the association between the independent variables and meconium-stained amniotic fluid (MSAF). An increased risk of MSAF was found for advancing gestational age, indicators of fetal stress, fewer than five prenatal care visits, and > 15 hours labor. After controlling for demographic and clinical characteristics, the risk of MSAF in black patients was approximately 1.5 times that of white patients. The higher proportion of MSAF in blacks could not be explained with obvious risk factors.

Adolescent↗
PubMedDate not supplied

Screening for cerebral palsy in preterm infants: delay criteria for motor milestone attainment.

We evaluated the efficacy of various delay criteria (12.5%, 25%, 37.5%, 5%, 50% delay) for motor milestone attainment to screen a sample of 173 high-risk preterm infants with gestational age < 32 weeks who had been sequentially followed for 18 to 24 months. Sensitivities were best with 12.5% and 25% delays, but specificities and positive predictive values were relatively lower. Since societal resources for evaluation and treatment of cerebral palsy are limited, the excellent specificities (81% to 95%) and positive predictive values (48% to 85%) with 50% delay are more important than the somewhat lower sensitivities, especially since milestones involve a multistep screening process. Screening preterm infants by obtaining a history of motor milestone attainment with each child care visit, correcting for degree of prematurity, and using a 50% delay criteria is a practical, inexpensive method of identifying infants at highest risk of cerebral palsy.

Cerebral Palsy↗
PubMedDate not supplied

Birth outcomes of Korean women in Hawaii.

Since the end of the Korean War, immigration of Koreans to the United States has increased rapidly. In 1990, 11.6 percent of all Asians in the United States were of Korean ethnicity, and it is projected that Koreans will outnumber all other Asian groups, except Filipinos, in the United States by the year 2030. Despite the growing size of this population, very little is known about their health status. This study, using 1979-89 Hawaii vital record data, investigates the relationship between maternal sociodemographic characteristics, prenatal care utilization factors, and birth outcomes among Koreans as compared with Caucasians. The ethnic term "Caucasian" is used in Hawaii's vital records and is synonymous with non-Hispanic whites. Korean mothers were more likely to be older and have lower educational attainment, and less likely to be adolescent, single, or to have received adequate prenatal care than Caucasian mothers. More than 80 percent of the Korean mothers were foreign born. Significantly higher risks for very preterm delivery (less than 33 weeks) and very low birth weight births were observed for Koreans as compared with Caucasians. Nativity had no effect on birth outcome in this population. The results of this study suggest that prevention of preterm birth is an important focus for improving pregnancy outcomes in this growing ethnic group.

Adolescent↗
PubMedDate not supplied

Quantifying the adequacy of prenatal care: a comparison of indices.

OBJECTIVES: In spite of the widespread use of prenatal care utilization indices in the scientific literature, little attention has been given to the extent to which these indices are comparable. This investigation contrasts the way five indices classified cases into categories of prenatal care use. METHODS: From the 1989-1991 South Carolina Public Use data files, single live births to resident mothers were selected for analysis (N = 169,082). Five prenatal care indices were compared: (a) the modified Institute of Medicine (Kessner) index, (b) a variation of the IOM index using the full American College of Obstetrics and Gynecology visit recommendation, (c) an index derived from the recommendations of the U.S. Public Health Service Expert Panel on Prenatal Care, (d) the GINDEX, and (e) the APNCU index. RESULTS: The proportion of cases assigned to prenatal care utilization categories by each index varied markedly, ranging from 33.6% to 58.1% for adequate care, 9.2% to 20.3% for inadequate care, and 7.4% to 22.6% for intensive utilization. CONCLUSIONS: The selection of a prenatal care utilization index for research and policy development purposes requires a careful consideration of the intent, criteria for defining adequacy, and coding assumptions of each index. As these indices are conceptually distinct in their measurement approach, they are likely to yield different patterns of prenatal care use in a population and cannot be used interchangeably. Recommendations for their use are provided.

Algorithms↗
PubMedDate not supplied

Conceptualization, measurement, and use of gestational age. I. Clinical and public health practice.

Despite its importance for both clinical and public health practice and the considerable effort spent during the past three decades to develop alternative estimation methods, the measurement of gestational age on both the individual and population level continues to be problematic. The availability of alternative approaches for the estimation of gestational age has to some extent obscured the basic differences in the conceptualization of these measures and influenced our current state of thinking about gestational age. As the evidence grows that these alternative gestational age estimation measures do not precisely correspond with one another, controversies have arisen regarding which method is most accurate. In the search for a single gestational age "gold standard," the potentially valuable information that these alternative measures may provide when used in combination should not be overlooked.

Female↗