Parental decision-making for the varicella vaccine.

INTRODUCTION: With the advent of new vaccines, improvements in established vaccines, and the availability of new combination vaccines, parents' decisions about vaccinating their children have become more complicated. This study examined parents' decision-making processes pertaining to whether to have their children vaccinated for varicella to gain a better understanding about how parents make vaccination decisions for their children. The "Awareness-to-Action Model" was used to examine parents' decision-making process before the action to vaccinate or refuse vaccination occurs. METHOD: This study used a cross-sectional design and logistic regression to test the explanatory power of several factors related to the parental decision-making process. A stratified random sample of 262 members of Kaiser Permanente Hawaii participated in the study. Data were collected through telephone interviews. RESULTS: In the "Awareness-to-Action Model," the decision construct was statistically significant in explaining parents' decisions to have their child vaccinated. The overall model correctly classified 80% of the sample as accepters or nonaccepters of the vaccination for their child. This study provides a model that enables health care providers to understand parental decisions about vaccines. This knowledge can help target interventions to increase vaccine compliance, thus minimizing the risk of diseases preventable by vaccine.

Changing pregnancy outcomes of Samoan women in Hawaii.

In the state of Hawaii, Samoan mothers are known for the large average birthweight and low percentage of low birthweight (< 2500 g) of their infants, in spite of the relatively low socio-economic status of the population. This paper reports the findings of a temporal trend analysis of birth outcomes of Samoan women and identifies worrying changes. Data were obtained from Hawaii birth certificates. Single live births to Hawaii-resident Samoan and Caucasian women from 1979 to 1994 were included in the study. Infants of Samoan women experienced a 75 g decline in mean birthweight and an increase in the percentage of low (< 2500 g) and very low (< 1500 g) birthweight from 2.6 and 0.4 to 3.8 and 0.8 respectively. During the same time, infants of Caucasian mothers experienced an increase in mean birthweight and a decline in low birthweight, while very low birthweight did not change. Maternal socio-demographic characteristics explained only part of the findings and use of prenatal care did not appear to be associated with any birth outcome indicators. Multiple regression analyses identified an adjusted loss of 50.8 g in birthweight and a 1.48 increase in the odds ratio of small-for-gestational-age associated with birth at the end (1991-4) compared with the beginning (1979-82) of the study period. Further studies focusing on maternal health status and psycho-social variables, including the effect of acculturation-related stress, are warranted to identify at least some of the determinants of the changes identified by this analysis.

Prenatal care utilization in Hawaii: did it improve during the last 16 years?

This paper examines the utilization of prenatal care in Hawaii from 1979 to 1994 to determine if early and adequate utilization of prenatal care has changed during this period. Birth certificates of single live born infants of resident women were the source of data for the study. During the study period, the proportion of women receiving prenatal care in the first trimester increased by nearly 5 percent but was still below the national and state Year 2000 health objective of 90 percent. Notwithstanding this improvement, the percentage of women who did not receive the recommended number of visits in spite of starting care early significantly increased. The overall proportion of women with 'intensive' prenatal care use markedly increased (134.7%). The proportion of women with 'inadequate' care use declined (10.3%), although the proportion of women with 'no care' use doubled. Complete reporting of use of care through birth certificates markedly deteriorated. The findings of this study indicate the need for changes in the targeting and provision of counseling and education on the part of health care providers. Public health leaders, policy makers, health care providers, and advocacy groups need to collectively review programmatic directions with an aim toward the development of innovative approaches to address the emerging health needs of mothers and infants in the state.

Temporal trends in maternal characteristics and pregnancy outcomes: their relevance to the provision of health services. Hawaii, 1979-1994.

This paper examines changes in maternal sociodemographic characteristics and pregnancy outcomes in Hawaii during the period 1979-1994. The more striking changes were increases of 129% in the proportion of births to women > 35 years old and of 67% in the proportion of births to unmarried mothers. The percentage of low birth weight and small-for-gestational age infants decreased while the proportion of premature births increased. Identified changes were not limited to selected population groups, but were found in various degrees in all ethnic groups. These findings are relevant to all health practitioners and will assist in the provision of appropriate care and counseling to individual women.

Multiethnic variations in the pregnancy outcomes of military dependents.

OBJECTIVES: We examined the pregnancy outcomes of three ethnic groups: African-American Blacks, non-Hispanic Whites, and Filipinos. In an attempt to reduce ethnic dissimilarities in parental employment and access to health care, this investigation compared the single-live-birth outcomes of married, adult women who resided in the state of Hawaii and who indicated that their spouse was on active-duty status in the US military. METHODS: The data for this study were obtained from the 1979-1989 Hawaii vital-record file that provides linked live birth-infant death information. Multiple logistic regression was used to calculate odds ratios for the independent effects of maternal factors on low birthweight and neonatal mortality. RESULTS: Significant differences in maternal age, maternal education, paternal education, parity, hospital of delivery, and use of prenatal care were observed among the ethnic groups. The results of a logistic regression analysis of low birthweight indicated significantly higher risks for Filipinos and Blacks compared with Whites. For very low birthweight, only an increased risk for Blacks was observed. No ethnic differences in neonatal mortality were found. CONCLUSIONS: This investigation revealed more comparable infant mortality experiences among the ethnic groups in spite of persistent birthweight differences.

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.

Rate of growth in length of Bangladeshi infants as a function of attained length.

We examine variation in the rate of growth in length of breast-feeding infants from rural Bangladesh. These data were collected between November 1985 and February 1986 from two rural sites. Eighty-eight infants, ranging from birth to 4 months of age at the start of the study and their mothers were measured monthly for 4 months. Length increased linearly with age over this 4-month period (infants' average bias-adjusted R2 = 0.90). The relationship between infant rate of growth in length and attained length was analyzed by two different methods: Oldham's (1962) method of regressing rate of growth on mean length and Blomqvist's (1977) method of regressing rate of growth on estimated initial length. The methods gave similar results. The rate of growth was negatively associated with mean infant length over the 4-month period (p less than 0.001); that is, shorter infants grew at a faster rate than longer infants. For every centimeter shorter the infant was, the rate of growth was 0.1 cm/mo faster on average; the effect was greater among males than among females. The average rate of growth was greater for males than for females and greater in financially solvent households and varied by site. Infant growth rate was slower among older infants than among younger infants, as expected. However, after adjusting for mean infant length, age was no longer significantly associated with infant growth rate, although mean infant length remained highly significant. Forty-one percent of the variation in infant rate of growth in length was explained by mean infant length, sex, sex by length interaction, household financial solvency, and site.

Maternal nativity status and pregnancy outcome among U.S.-born Filipinos.

Using 1979-87 Hawaii vital record data on single live births, this study compares by nativity status of the mother the maternal characteristics and pregnancy outcomes of resident Filipino women. Among ethnic minorities in the United States, the pregnancy outcomes of U.S.-born mothers have been reported to compare unfavorably to their foreign-born counterparts. In this study, unequivocally preferential pregnancy outcome indicators were not observed for foreign-born women. Contrary to expectations, a significant, but modest, increase in the risk of preterm delivery was found for infants of Philippines-born mothers, along with a less favorable mean birth weight and gestational age. As a growing minority population in the United States, the atypical determinants and patterns of pregnancy outcome in this population warrants further investigation.

Investigation of institutional differences in primary cesarean birth rates.

Differences in primary cesarean birth rates between a maternity center staffed by certified nurse-midwives (CNM) with physician backup on the premises and a university teaching hospital staffed by resident and attending physicians were studied. The study sample included 796 and 804 women, similar in demographics, who received their prenatal and intrapartum care in the respective sites in 1977 and 1978. Study results indicate a significantly lower rate of primary cesarean birth at the maternity center than at the university hospital that was independent of institutional differences in the indications for abdominal delivery. Although cesarean birth was related to contracted pelvis (at labor), fetal malpresentation, and placental bleeding at both institutions, it was significantly associated with preeclampsia, primiparity, fetal distress, and maternal age only at the university hospital. There were no noteworthy differences in pregnancy outcomes for women delivered vaginally or by cesarean, except for more newborns with low Apgar scores among primary cesarean births at the university hospital. A likely explanation for these findings is differing labor and delivery management styles between the providers of care at the two institutions.

Causes of infant mortality in a multiethnic population.

Causes of infant mortality and their change over time in five ethnic groups were investigated using linked infant death and live birth certificates from the State of Hawaii, 1968-1983. Over the study period, there were 3,324 deaths of which 31 percent were to Whites, 26 percent to Hawaiians, 17 percent to Asians, 15 percent to Filipinos and 10 percent to other ethnic groups. Significant changes in the proportion of deaths by cause occurred over the period. Perinatal causes remained the most frequent, but their relative contribution to annual infant deaths declined from 61 percent to 47 percent. The proportion of deaths from congenital anomalies increased from 19 percent to 30 percent, while the proportion of deaths from infectious diseases declined from 14 percent to 4 percent. There was a significant difference in the proportion of deaths by cause between ethnic groups in the early years of the study period. However, during the last four years 1980-1983, no significant difference between ethnic groups was observed.

Episiotomy and its role in the incidence of perineal lacerations in a maternity center and a tertiary hospital obstetric service.

This study examines the use of episiotomy and the frequency of perineal lacerations in a primary care maternity center staffed by certified nurse midwives (Booth Maternity Center) and a tertiary care teaching hospital where deliveries were performed by physicians (Thomas Jefferson University Hospital). The study sample (1262 women) was a stratified random selection of singleton live births in 1977 and 1978 at Booth Maternity Center and Thomas Jefferson University Hospital, with the demographic characteristics of women at Booth Maternity Center used as the sampling frame. Data were abstracted from medical records. Clinical and demographic factors that might be associated with the likelihood of having an episiotomy or experiencing a perineal laceration were examined using logistic regression. After controlling for other significant factors, women at Thomas Jefferson University Hospital were twice as likely to have an episiotomy as women at Booth Maternity Center. Use of an episiotomy was associated with a decrease in perineal lacerations of first- or second-degree, but a fourfold increase in the incidence of third-degree lacerations.

Variations in pregnancy outcomes and use of obstetric procedures in two institutions with divergent philosophies of maternity care.

Pregnancy outcomes were compared between a stratified random sample of 796 women delivering a live birth at a maternity center (BMC) and a frequency matched sample of 804 women delivering a live birth at a tertiary hospital (TJUH) in 1977-1978. The relationship of use of obstetric procedures with pregnancy outcomes was investigated within and between the two samples. The neonatal morbidity rate, as measured by Hobel's neonatal risk score, was significantly higher and mean birth weights were lower at TJUH than at BMC when adjusted for institutional differences in use of obstetric procedures, medical-obstetric risk, and demographic characteristics. Conversely, the proportion of newborns with low 1-minute Apgar scores (fewer than seven) was significantly greater at BMC. The relationship of use of obstetric procedures with each outcome varied between the two institutions as well as across the three measures of pregnancy outcomes. The relationship of use of some procedures with each outcome may be explained in part by use of the procedure because of a suspected poor outcome of pregnancy, rather than an elevated risk of poor outcomes because of use of the procedure. Self-selection of some patients to BMC cannot be ruled out as a possible explanation for institutional differences.

The impact of the Mississippi Improved Child Health Project on prenatal care and low birthweight.

A quasi-experimental, nonequivalent control group design was used to evaluate the Improved Child Health Projects in northwest Mississippi (ICHP1 and ICHP2). Control counties were selected for each project that on average were similar to ICHP counties on racial composition, median family income in 1970 and 1980, and number of births in 1978-79. The study population comprised all resident births in the ICHP and control counties during a pre-ICHP period (1975-78) and the ICHP period (1979-81). The percentage of women with adequate prenatal care rose between the two periods for all counties; the rise was greater for the study than for the control counties for ICHP1; the reverse was found for ICHP2. For both projects, the low birthweight rate remained constant in the pre-ICHP and ICHP periods for the study and control counties. Adjustment for changes in the childbearing characteristics between the two periods did not alter these results. Community involvement in its development and coordination may explain ICHP1's impressive rise in the use of prenatal care.

The use of preventive health services by disabled children.

As a measure of the use of general pediatric health services we assessed disabled children's receipt of preventive health care in relation to a control group of nondisabled children, matched by age, family size, and region of residence. The study and control subjects were identified in a household survey conducted in Minnesota in 1976 and ranged in age from 1 to 18 years. The proportion who made a preventive health visit was nearly identical in both groups. Binary variable multiple regression showed that 9 percent of the variation in outcome was explained by the independent variables, which included demographic and socioeconomic characteristics and access to health care. Disability did not contribute significantly to the explained variation, but family structure, mother's education, and mother's use of preventive health services reached the 95 percent level of significance. The results suggest that children in a community who are identified as disabled are not at a disadvantage, in comparison with the nondisabled, in gaining access to preventive health services. The use of such services by all children appears to be low when information on using school health services is not available.

Patterns of obstetric procedures use in maternity care.

The use of seven obstetric procedures was studied in two institutions that use different approaches to maternity care. The study population included 796 women delivering at Booth Maternity Center and 804 women with similar sociodemographic characteristics delivering at Thomas Jefferson University Hospital during 1977 and 1978. Several differences were found between the two institutions. The majority of selected procedures were used more often at Thomas Jefferson University Hospital than at Booth Maternity Center. The greatest differences were found for women at low intrapartum risk, while differences were smallest for women at high prenatal and intrapartum risk. The two institutions differed in their use of procedures for women at various levels of prenatal and intrapartum risk. The findings suggested that most of the differences did not reflect different levels of risk in the populations served, but were due to other unidentified factors.

Evaluation of a measure of neonatal morbidity.

The neonatal risk score of Hobel et al. was evaluated as a measure of neonatal morbidity in a sample of 1,600 singleton infants born alive at two institutions. The score was evaluated for internal consistency, the appropriateness of weight assigned to factors, criterion validity, and conformity to the negative binomial distribution. The results are encouraging for the use of the score as a measure of neonatal morbidity. It appears internally consistent. All risk factors occur with some frequency with at least one other and, in most instances, with several others. With one exception, all factors distinguish infants with high and low scores. The neonatal score, defined by a weighted score and by the number of factors, is highly correlated with length of infant stay in the nursery. Correlations are higher for scores of events measured after birth than for scores of events measured directly at birth. The authors recommend that the number of risk factors be used in preference to the weighted neonatal score since it conforms to the negative binomial distribution and is simpler to calculate. The potential uses of a quantitative, comprehensive measure of neonatal morbidity ar discussed.

A study of pregnancy outcomes in a maternity center and a tertiary care hospital.

This study compares 796 pregnancy outcomes at a maternity center (BMC) with 804 hospital (TJUH) pregnancy outcomes. The samples of pregnant women from the participating institutions were matched on sociodemographic characteristics; analysis of outcomes was performed controlling for medical-obstetric risk. Differences between the institutions were found mainly among women with low intrapartum risk. For these women, neonatal morbidity and length of infant nursery stay were lower at BMC than at TJUH. The percentage of infants with one-minute Apgar scores less than 7 or requiring resuscitation at birth was greater at BMC, but the percentage of infants with five-minute Apgar scores less than 7 as well as neonatal mortality rates did not differ between the two institutions. The number of women with intrapartum or postpartum fever was too small to permit comparison. The study results suggest that care delivered at BMC is safe with regard to the evaluative criteria used.

Definitions of high risk in pregnancy and evaluation of their predictive validity.

The predictive validity of Hobel's criterion (score of 10 or more) for high prenatal and intrapartum risk and two alternative definitions was evaluated in two sociodemographically similar samples from two different institutions. At one institution, intrapartum risk was associated with neonatal morbidity independently of prenatal risk; at the second institution, both were related to neonatal morbidity, depending on the definition of high risk. Definition of high risk as a score of 15 or more improved the prognostic ability of Hobel's method at the first institution, but not at the second. Grouping prenatal and intrapartum risk as low (0 to 9), medium (10 to 19), and high (20 or more) provided a clearer understanding of the association between prenatal/intrapartum risk and neonatal morbidity, although differences between the two institutions persisted. Modifications and validation of risk assessment methods are necessary when used in populations other than the one for which they were originally developed.