COVID-19 in Eye Surgery: The Case of a University Hospital

Coronavirus epidemic has quickly become a global health threat. The ophthalmology department, like all other departments, have adopted resource management and personnel adjustment maneuvers. The aim of this work was to describe the impact of covid on the Ophthalmology Department of University Hospital "Federico II" of Naples. In the study logistical regression was used for a comparison between the pandemic and the previous period, analyzing patient features. The analysis showed a decrease in the number of accesses; reduction of the length of stay; and the statistically dependent variables are as follows: LOS, discharge procedures and admission procedure.

What Leads to a Patient Refusal for Ambulatory Surgery? A Logistic Regression Prediction Model Based on a 5-year Retrospective Analysis of Patients with Abdominal Wall Hernia

INTRODUCTION

Ambulatory surgery has proven benefits in patient wellbeing and cost reduction in healthcare systems. However, some patients referred for ambulatory surgery are refused and directed instead towards inpatient care, which generates several drawbacks. The reasons for this refusal have not been yet studied. The aim of this study is to identify, retrospectively, significant variables associated with patient refusal for ambulatory surgery and develop a mathematical tool able to predict with strong accuracy those who will be rejected.

MATERIAL AND METHODS

Over a 5-year period (2014 - 2018), all patients that underwent abdominal hernia repair in our hospital in an inpatient setting, and that had been previously refused for ambulatory surgery, were analysed for a total of 94 variables. A multivariate logistic regression model was developed to identify risk factors associated with refusal using data from 136 patients (65 refused vs 71 accepted). A prediction index for refusal in ambulatory surgery - IRAS - was derived and tested (n = 62 patients).

RESULTS

The risk index included five significant risk factors: type 2 diabetes mellitus [OR 14.669 (2.982; 72.154)], physical status [OR 49.155 (15.532; 155.555)], prior malignancy [OR 14.518 (2.653; 79.441)], prior abdominal surgery [OR 3.455 (1.006; 11.866)] and usage of antiplatelet agents [OR 25.600 (4.309; 152.066)]. All risk factors were associated with a high risk of refusal (OR between 3.455 for history of prior abdominal surgery and 49.155 according to the American Society of Anaesthesiologists physical status classification). Defining five points as the maximum IRAS score that predicts suitability for ambulatory surgery resulted in a positive predictive value of 93.55% and negative predictive value of 87.10%.

DISCUSSION

Significant patient variables for refusal of an ambulatory procedure were determined and an easy to use risk index - IRAS - was built that is able to predict with good accuracy which patients will be refused.

CONCLUSION

IRAS is a useful tool that can contribute to reduce time to surgery and improve patients' quality of life.

Estimation of heritability and genetic correlation of body weight gain and growth curve parameters in Korean native chicken

Objective

This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC).

Methods

A total of 585 F₁ chickens were used along with 88 of their F₀ birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fitted to the longitudinal growth dataset to obtain three growth curve parameters (α, asymptotic final body weight; β, inflection point; and γ, constant scale that was proportional to the overall growth rate). Genetic parameters were estimated based on the linear-mixed model using a restricted maximum likelihood method.

Results

Heritability estimates of body weight gain traits were low to high (0.057 to 0.458). Heritability estimates for α, β, and γ were 0.211±0.08, 0.249±0.09, and 0.095±0.06, respectively. Both genetic and phenotypic correlations between weight gain traits ranged from −0.527 to 0.993. Genetic and phenotypic correlation between the growth curve parameters and weight gain traits ranged from −0.968 to 0.987.

Conclusion

Based on the results of this study population, we suggest that the KNC could be used for selective breeding between 6 and 8 weeks of age to enhance the overall genetic improvement of growth traits. After validation of these results in independent studies, these findings will be useful for further optimization of breeding programs for KNC.

The effects of family planning workers' contact on fertility preferences: evidence from Bangladesh

Should family planning programs put more effort into persuading couples to want smaller families or into helping women achieve their reproductive goals? Indeed, can family planning programs affect fertility preferences? Longitudinal data from Bangladesh collected from 1982 to 1993 show that women's desired family sizes have declined dramatically. This study examines how the decline in desired family size is related to visits from family planning workers for three intervals: 1982-85, 1985-90, and 1990-93. By use of logistic-regression analysis, the number of rounds during which women received visits from family planning workers is found to have no statistically significant effect on the probability that women altered their preference from wanting more children at the beginning of an interval to wanting no more at the end of the interval.

Using logistic regression to describe the length of breastfeeding: a study in Guadalajara, Mexico

This study seeks, through a logistic regression model, to describe the pattern of breastfeeding duration in Guadalajara, Mexico, during 1993. A multistage random sample of children under 1 year of age (n = 1036) was studied; observational data regarding breastfeeding duration, obtained through a "status quo" procedure, were compared with prevalence rates obtained from the logistic regression model. Modeling the duration of breastfeeding during the first year of life rather than only analyzing observational data helps researchers to understand this process in a dynamic and quantitative way. For example, uncommon indicators of breastfeeding were derived from the model. These indicators are impossible to obtain from observational data. The prevalence curve estimated through the logistic model was adequately fitted to observed data: there were no significant differences between the number or distribution of breastfed infants observed and those predicted by the model. Moreover, the model revealed that less than 40% of the children were breastfed in the fourth month of life; the median age for weaning was 39.3 days; 55% of the potential breastfeeding in the first 4 months did not occur; and the greatest abandonment of breastfeeding in the first 4 months was observed in the first 60 days. Thus, logistic regression seems a suitable option to construct a population-based model that describes breastfeeding duration during the first year of life. The indicators derived from the model offer health care providers valuable information for developing programs that promote breastfeeding.

Fertility of Danish battery workers exposed to lead

BACKGROUND

Inorganic lead may impair male fecundity through its action on the germinal epithelium, the endocrine system or both, but information on possible impact on fertility in exposed populations is limited.

METHODS

Fertility was examined in 1349 male battery plant employees and in 9596 reference company employees over a follow-up of 25,949 and 183,414 person years respectively. The cohorts were identified by records in a national pension fund and information on births was obtained from the Danish Population Register. In a subset of the battery worker cohort, the average level of lead in blood was 35.9 micrograms/dl (4639 blood samples on 1654 person years in 400 workers; SD 13.0; range 3-125). The birth rate was analysed by logistic regression on occupational exposure and several extraneous determinants (age, parity, calendar year, and previous children).

RESULTS

The birth-rate was not reduced in years at risk from exposure to lead in comparison with years not-at-risk; either in comparison with not-at-risk years within the battery plant cohort (odds ratio [OR] = 0.997, 95% confidence interval [CI]: 0.88-1.13), or in comparison with the external reference population (OR = 0.983, 95% CI: 0.87-1.11).

CONCLUSIONS

Inorganic lead seems not to impair fertility among Danish battery workers. This finding does not rule out that the time taken to achieve a pregnancy is increased among battery workers because most pregnancies in Denmark are planned.

Sex differentials in perinatal mortality in China and Finland

This study describes patterns of sex differentials in perinatal mortality in China and Finland. The analysis is based on three population-based one-year birth cohorts, one from Qingdao, China, in 1992 and two from Northern Finland in 1966 and 1985-86, comprised of 9,219, 11,422 and 9,207 singletons with at least 28 gestational weeks and 1000 g in birthweight, respectively. Both Finnish cohorts had an excess of male over female perinatal deaths, but in the Chinese cohort girls were more likely to die than boys. The adjusted odds ratio (OR) of perinatal mortality for boys was 1.31 (95 per cent confidence interval [CI] 0.98, 1.78) and 1.57 (95 per cent CI 0.89, 2.78) in the Finnish 1966 and 1985-86 cohorts, respectively, and 0.82 (95 per cent CI 0.55, 1.20) in the Chinese cohort. The corresponding figure for stillbirths in the Chinese was 0.57 (95 per cent CI 0.33, 0.98), which could explain the total excess of female deaths during the perinatal period. Our results suggest that the role of different social and cultural environments on the existing sex differentials in perinatal mortality between the countries needs further evaluation.

Early predictors of nonmarital first pregnancy and abortion

Most research on abortion has focused on women's characteristics at the time of the procedure, but individuals' behavior may also be shaped by their experiences from younger ages. This study uses longitudinal data on 351 California white women aged 27-30 in 1990-1991 to identify characteristics in childhood and adolescence that predict who will have a nonmarital first pregnancy and, of those who do, which women will seek an abortion. Bivariate analyses reveal that psychosocial characteristics indicating a strong sense of autonomy, such as feeling it is important not to be tied down and engaging in socially undesirable behavior, are significantly associated with the likelihood of having a nonmarital first pregnancy (odds ratios of 1.7 and 1.5, respectively), but family characteristics are not. However, among women who have a first pregnancy out of wedlock, the odds of having an abortion are mostly influenced by family rather than psychological characteristics, particularly having been a good student and having a well-educated mother (2.0 and 1.7).

Stage of behavior change for condom use: the influence of partner type, relationship and pregnancy factors

A theoretical model was used to examine the influence of relationship factors, pregnancy intentions, contraceptive behavior and other psychosocial characteristics on stages of behavior change in condom use among heterosexual black women of reproductive age. Data from an inner-city street survey compared women who were not contemplating condom use, women who were attempting to use condoms or had used them consistently for short periods of time, and those who had achieved long-term consistent use. Women's relationship with their main partner appears to be an important factor in understanding their use of condoms both with main partners and with other partners. For condom use with the main partner, factors such as emotional closeness and partner support were significant predictors of the likelihood that women would be attempting to use condoms rather than not contemplating use. Cohabitation and the belief that condom use builds trust were significant predictors of long-term consistent condom use. Having a regular or main partner was strongly associated with intentions to use condoms with other partners. Women who wanted to become pregnant were much less likely to intend to use condoms with their main partner, and women using oral contraceptives were less likely to be long-term consistent condom users.

Variations in familial neonatal mortality risks in four countries

This paper investigates variations in the strength and structure of familial association in neonatal mortality risks in four populations; Bolivia, Kenya, Peru, and Tanzania. Exploratory analyses of the structure of the familial association are presented for each population. Random effects logistic models are then used to estimate the strength of familial association in neonatal mortality risks using a standard set of control variables. The results suggest that the strength of familial association in neonatal mortality risks is quite similar in these four populations which would be consistent with a biological explanation for the association. However, some differences were found, particularly in the form of the association in Peru, which may suggest at least a small role of other factors.

Determinants of contraceptive use in Morocco: stopping behaviour in traditional populations

The determinants of modern contraceptive use in traditional populations are analysed in married women aged 30-44 living in the province of Marrakech (Morocco). Women who have never used contraception have smaller family sizes than those who do: the number of live children (or live births) is the variable with maximum predictive power on contraceptive use, while child mortality is the main inhibiting factor. The probability of contraceptive use increases with female age at marriage and decreases with the woman's age, indicating a generational change in reproductive behaviour. The socioeconomic variables education, employment and residence, have no significant independent predictive character on contraceptive use, although the interaction between education and residence does. The paper evaluates the hypothesis that traditional populations in the initial phase of their demographic transition resort to modern contraception in order to stop childbearing, when they have reached a desired number of children, rather than to space births or reduce their fertility.

Birth spacing and infant and early childhood mortality in a high fertility area of Bangladesh: age-dependent and interactive effects

To examine the effects of birth spacing on early childhood mortality, 3729 singleton births in 1983-84 were followed for 3 years in rural Bangladesh. Logistic regression analyses were used to assess whether the survival of older siblings modifies the effect of preceding birth intervals and to see if the effects of preceding and succeeding birth intervals are inter-related, controlling for the effects of sex of the child, mother's age and household economic status. With the exception of the neonatal period, birth spacing effects were highly significant. A preceding birth interval of < 15 months was associated with a greater mortality risk in the post-neonatal period for children with an older sibling who survived infancy. However, a short preceding birth interval did not adversely affect post-neonatal mortality if the older sibling died in infancy. Neonatal and post-neonatal deaths were higher if older siblings had died in respective age intervals. A pregnancy interval of < 12 months after childbirth raised the risk of death at ages 1-2 years considerably if the child was born after a short birth interval (< 15 months). The results suggest that the high mortality risks of closely spaced children are due to sibling competition for parental resources.

Determinants of infant mortality in Malawi: an analysis to control for death clustering within families

The 1988 Malawi Traditional and Modern Methods of Child Spacing Survey data are used to identify determinants of infant mortality in Malawi. The logistic binomial analysis shows that socioeconomic factors are significant even during the neonatal period while the length of the preceding birth interval is significant in the post-neonatal period only. There is a strong familial correlation of mortality risks during both the neonatal and post-neonatal periods but the effect of geographical area of residence is stronger in the post-neonatal period.

Effect of maternal age on birth outcomes among young adolescents

This study examined the effect of maternal age on birth outcomes among young adolescents, ages 10 through 15. All records representing single births of primipara, Black or White adolescents, were selected for analysis from the 1983-1986 National Center for Health Statistics' Public Use Linked Live Birth-Infant Death Data File (n = 127,668). Logistic regression analyses controlled for effects of maternal race, marital status, prenatal care, gravidity, education, and metropolitan/nonmetropolitan residency. Univariate analyses indicated that the youngest adolescents were at greatest risk for negative birth outcomes including very preterm and preterm delivery, low birth weight, small for gestational age (SGA), and neonatal mortality. Logistic analyses showed similar results, with the exception that differences in SGA were insignificant. This study indicates the importance of examining age-specific birth outcomes among a population that has traditionally been studied in aggregate and underscores the need for increased prevention efforts.

The marriage squeeze and the rise in informal marriage in Brazil

Around the world, populations have experienced shortages of one sex or the other at marriageable ages, as a result of mortality declines. The solutions to this problem vary with the cultural context. Declines in the spousal age difference and increases in dowry payments (India) and polygamy (Africa) are two adjustments to a disequilibrium in the marriage market. We hypothesize that in Brazil the marriage market finds its balance by "recycling" men through highly unstable informal unions. Using census and 1984 survey data, we establish the relationship between a marriage squeeze and the increase in informal marriage. Census data and a competing-risks analysis of marriage choice provide evidence that a marriage squeeze has affected both the chances of marrying at all and the type of marriage entered.

Some unknown episodes in the history of population dynamics concerning the logistic law: the lesson of the great epidemiologists

The author discusses the work of "the two great epidemiologists R. Ross and A. G. McKendrick. This talk is basically devoted to their 'lesson' about logistic theory and it is organised as follows: section 2 is devoted to McKendrick's [1911] contribution to the growth of microorganism populations, a paper which was not widely acclaimed, but which marks the first experimental laboratory verification of the logistic law. Section 3 is also devoted to McKendrick and to the way he repeatedly derived the logistic equation as a model for 'simple epidemics'. Finally, in section 4, we present Ross's 'A priori pathometry' theory that really emphasizes...the role played by the logistic law as the 'first principle' of the mathematical epidemiology."

Pre-marital fertility in Liberia

This analysis of the 1986 Liberia Demographic and Health Survey data finds remarkably high fertility levels among women who have never married or lived with a man, reflecting widespread pre-marital sex and a lack of use of contraception. It is found that single Liberian women are more likely to foster out children than married Liberian women of the same age.

Maternal marital status as a risk factor for infant mortality

The increased risk of infant mortality associated with single motherhood is neither consistent among social and demographic subgroups nor inevitable, according to data from national linked birth and infant death files for 1983-1985. Maternal age is the only variable found to have a significant interaction with marital status among black mothers, and the risk associated with unmarried status increases with age. Among white mothers, age, educational level and receipt of prenatal care all show significant interactions with marital status; the increased risks of infant mortality attributed to unmarried motherhood are concentrated among subgroups usually thought to be at lower risk. For example, the risks of infant mortality among unmarried white women relative to married white women are highest among 25-29-year-olds. However, being unmarried did not affect the risk of infant mortality among babies born to college-educated white women.

Infant mortality in Nigeria: effects of place of birth, mother's education and region of residence

This paper examines the effects of a child's place of birth, mother's education, region of residence and rural and urban residence on infant mortality in Nigeria between 1965 and 1979, using data from the 1981/82 Nigeria Fertility Survey. Infant mortality rates declined in all regions between 1965 and 1979. Children born in modern health facilities, irrespective of their mothers' place of residence, experienced significantly lower rates of infant mortality than those born elsewhere. Logistic regression analysis showed that all other variables tested were also significant, although some to a lesser degree. Efforts to reduce infant mortality in Nigeria should include policies that rectify rural and urban differentials in the distribution of health facilities and encourage their use.

Some correlates of child mortality in the refugee populated regions in Tanzania

Data from the 1988 Tanzania census were used to examine child mortality in three regions populated with Burundi refugees. Logistic and least squares analyses show that for both Tanzanian nationals and refugees low levels of maternal education are associated with high child mortality levels. Children born to mothers who are housewives are associated with low levels of mortality compared to those born to employed mothers, though the results were not statistically significant for the refugees. Maternal demographic status, computed from age and parity, has a strong effect on child survival. Unexpectedly, child mortality was lower where the water source was a well outside the village. Tanzanian mothers who are at highest risk of childbearing are roughly 6.4 times more likely to have a child death than those at lowest risk; the corresponding figure for the refugees is 36.8. This emphasises the need to intensify family planning programmes in these regions.

User characteristics and oral contraceptive compliance in Egypt

Results from the 1988 Egypt Demographic and Health Survey show that many women are not taking oral contraceptives in a manner that ensures full protection by the method. Reports from 1,258 current pill users show a range of incorrect use; 63 percent of women surveyed reported an interruption in their use of the pill in the past month, and of those women, only 40 percent took the correct action when they missed a pill. The majority (89 percent) did not wait the correct number of days between packs. Multivariate analysis revealed that rural women were more likely to take pills out of sequence, compared with their urban counterparts. Failure to take a pill within the previous month was strongly associated with the experience of side effects. The younger women surveyed were more likely to know the correct interval between pill packs than were older women; and women who wanted more children were more likely to know the correct interval than those who did not. The use patterns exhibited by the pill users may be the result of their receiving confusing, incorrect, or incomplete information, and highlight the need to provide women with accurate, updated, and comprehensible information about oral contraceptives.

Determinants of couple agreement in U.S. fertility decisions

An analysis of data from 8,450 women interviewed in 1988 for the National Survey of Family Growth finds that teenagers, never-married women, black women and those with less than a high school education are less likely than other women to have a birth that is jointly desired by both partners; 29%, 35%, 45% and 51% of births, respectively, are wanted by both partners, compared with an overall average of 69%. Third and higher order births are also less likely than earlier births to be jointly planned--58%, compared with 69% of first births and 76% of second births. In situations in which the birth is not jointly planned, black women, unmarried women, teenagers and women having third or higher order births are all significantly more likely than other women in their race, marital status, age and birth-order categories to have a birth when the man's preference is unknown. Never-married women are significantly more likely than married women to have a birth when the woman desires one but the man does not, while black women are significantly more likely than white women to have a birth that the man wanted but that the woman did not.

Factors affecting desired family size in Bangladesh

Factors affecting desired family size in rural Bangladesh are examined using data from contraceptive prevalence surveys conducted between 1983 and 1991. The analysis suggests that mothers having two sons and one daughter are more inclined to perceive their family as complete than those having three sons and no daughter. Logistic regression analysis indicates that important determinants of desire for more children are age of woman, current contraceptive use status, work status, and family planning worker's visit. The policy implications of these findings are discussed.

Education and assortative marriage in northern and urban Sudan: 1945-79

This study examines the extent of assortative mating for education in Northern Sudan and urban Khartoum. More males than females were found at higher levels of education. Increasingly, people tend to marry persons of equal educational level, but the unequal educational opportunities for males and females have led to the emergence of educational exogamy in which members of different educational levels are more likely to marry from the adjacent educational category than from distant categories. The increasing level of education for both sexes, and especially for females, may in part explain the rising trend in age at marriage.

Use of obstetric services in rural Nigeria

The pattern and determinants of maternal service utilization were studied in a rural Nigerian community. The study sample consisted of 488 randomly selected women who had a childbirth or an abortion between May 1987 and September 1989. Although 93% registered for prenatal care in a health care institution, only 51% delivered in a health institution while 49% delivered at home mainly under the care of traditional birth attendants. Factors found to be most consistently associated with the use of health institutions for delivery were maternal education and occupation, religion, and occupation of the husband. Maternal age, parity and marital status and place of the residence were not significantly associated with the choice between home and institutional delivery. Logistic regression analysis was used to determine the odds ratio and to quantify the weight of these independent variables found to be significantly associated with the place of delivery as the outcome variable.

The socio-cultural context of high fertility among Igbo women

The Igboland of Nigeria has been under the influence of socio-economic change since the turn of the century, as typified by a high literarcy rate, a highly migratory population, the predominance of Christianity, and built-up towns and villages. Yet Igbo fertility has remained high even by Nigerian standards. Part of the explanation for high Igbo fertility is the prevalence of peculiar socio-cultural institutions which tend to encourage or support high fertility. In this study fertility differentials, reproductive behaviour and fertility preferences and intentions are examined as a function of three well-recognised cultural institutions or contextual factors: the bestowal of high fertility honour or title to women of a given family size, patriarchal relations, and patrilinearity and son preference, together with individual status indicators. Our findings suggest that socio-cultural institutions establish or condition relationships and behaviours among the Igbo; in other words, individual fertility behaviour takes place within the context of complex social organisation and under the influence of multiple social, cultural and ideological realities.

Age-specific patterns of association between breast cancer and risk factors in black women, ages 20 to 39 and 40 to 54

Data from the 1980 to 1982 population-based Cancer and Steroid Hormone case-control study of women 20 to 54 years old afforded the opportunity to investigate risk factors for breast cancer among black women younger than 40 years (177 patients and 137 control subjects) and to compare the results to black women 40 to 54 years old (313 patients and 348 control subjects). Information on exposure variables was obtained by in-person interviews. The logistic regression results indicated that the risk of breast cancer among black women younger than 40 years was nearly three times greater for those who used oral contraceptives for more than 10 years relative to never-users (odds ratio, 2.8; 95% confidence interval, 1.2 to 6.8) and more than four times greater for severely obese women (body mass index > or = 32.30 kg/m2) relative to women whose relative weights were less than 24.90 kg/m2. Patterns of association for the two age groups were similar for surgical menopausal, age at first full-term pregnancy, and multiple births, but differed for age at menarche.

Associations between social and environmental factors and perinatal mortality in Jamaica

Social and environmental factors in Jamaica were compared between 9919 mothers delivering in a 2-month period a singleton who survived the early neonatal period and 1847 mothers who were delivered of a singleton perinatal death in a contiguous 12-month period. Logistic regression showed independent positive statistically significant increased odds of having a perinatal death among mothers who lived in rural parishes, older mothers (aged 30 +), single parents, no other children in the household, large number of adults in the household, mother unemployed, the major wage earner of the household not being in a managerial, professional or skilled non-manual occupation, the household not having sole use of toilet facilities, smaller mothers and those classified as obese or undernourished. Variations were found for different categories of death. Intrapartum asphyxia deaths were not related to union (marital) status, occupation of major wage earner, number of adults nor to the use of the toilet. Antepartum fetal deaths did not vary significantly with occupation of major wage earner or maternal height, but did show a relationship with maternal education, mothers with lowest levels having reduced risk. Deaths from immaturity were significantly related only to occupation of major wage earner, number of children in the household, number of social amenities available (negative relationships) and maternal age (< 17 at highest risk). In conclusion there was little to indicate that social deprivation per se was related to perinatal death, although specific features of the environment showed strong relationships.

Nutritional status and early warning of mortality in southern Ethiopia, 1988-1991

OBJECTIVE

Ethiopian Government guidelines on nutritional survey data and relief provision call for intervention once mean weight-for-length (W/L) in an area falls below 90% of reference, on the basis that mortality is unlikely to rise until this level is reached. In this paper the appropriateness of the 90% cut-off is examined using data from Wolayita, southern Ethiopia. SURVEY DESIGN AND SUBJECTS: Fifteen to 25 villages are selected at random for survey each year, with all children 70-110 cm in length being followed up every 2 months. During the 3 years covered by these analyses 21,701 W/L measurements were made on 5455 children from 65 villages. 126 of the children died.

RESULTS

In the first and third survey years, rapid declines in mean W/L were recorded, with mortality increasing very roughly three-fold (compared to year 2, P < 0.01), even though mean W/L remained at or above 90% of reference at all times. A logistic regression analysis relating mortality to W/L indicates that between 20% and 35% of the greater mortality in years 1 and 3 can be explained by the observed changes in W/L. The remainder occurred because of an increase in underlying or background risk (which might perhaps be expected in the circumstances of generally deteriorating nutritional status).

CONCLUSIONS

The results suggest that child mortality is likely to increase before area mean W/L falls to 90% of reference, indicating that emergency interventions should be triggered earlier than at present.

Does women's literacy affect desired fertility and contraceptive use in rural-urban Pakistan?

The 1984-85 Pakistan Contraceptive Prevalence Survey showed that urban wives had more than twice the literacy rate of rural wives. The present study explored the relationship of the rural-urban gap in female literacy to differences in contraceptive use. In rural areas, literacy did not increase women's perceptions of having reached a 'sufficient' number of living children, although the opposite was true for urban areas. Yet rural women with an 'insufficient' number of living children were more likely to use contraception if they were literate, as did their urban counterparts. Thus, raising the literacy rate in rural Pakistan would not narrow the rural-urban gap in contraception to cease childbearing but would narrow the rural-urban gap in contraception used to space wanted births further apart. Recommendations for government policy are made.

State income tax policy and family size: fertility and the dependency exemption

Tax exemptions for dependents are a subsidy to having children and therefore create incentives for fertility. This article explores the relationship between the changing tax value of the state exemption for dependents—combined with the federal exemption—and the observed fertility choices of married couples. Using data from the Panel Study on Income Dynamics (PSID), the article finds that the federal exemption does have a positive impact on differential period fertility for the sample of 229 married couples in this study. This effect is dampened by an offsetting labor force participation and marginal tax rate effect, but it does provide evidence that fiscal policy can influence fertility. State income tax exemptions do not appear to significantly influence the fertility decisions of the sample.

Adolescent life events and their association with the onset of sexual intercourse

This study examined the timing of several events marking the transition from adolescence to young adulthood and their correlation with the age at first sexual intercourse. The model included parental disruption, dropping out of school, working, drug use, and dating. Socioeconomic status, gender, and race were included as control variables. Data are taken from the National Survey of Children, a longitudinal study of children ages 7-11 in 1976 who were reinterviewed in 1981 and 1986. Factors associated with first intercourse include age, tobacco use, marijuana use, dating, and parental divorce during the child's adolescent years. Age interacts with dating, working, and the use of illegal substances, and race interacts with dating and dropping out of school in their influence on first intercourse. Other transitions, such as alcohol use, parental divorce before adolescence, and parental marriage, had little influence on first sexual intercourse. Events such as dating appear to increase the risk of first intercourse, while the use of drugs may reflect a set of behaviors that occur simultaneously with sexual initiation. The correlated transitions identify a group of adolescents at risk for early sexual activity.

Hierarchical logistic regression models for imputation of unresolved enumeration status in undercount estimation

"In this article we describe a logistic regression modeling approach for nonresponse in the [U.S.] Post-Enumeration Survey (PES) that has desirable theoretical properties and that has performed well in practice.... In the 1990 PES, interviews were not obtained from approximately 1.2% of households in the sample, and approximately 2.1% of the individuals in interviewed households were considered unresolved after follow-up....The missing binary enumeration statuses for these unresolved cases were replaced with probabilities estimated under a statistical model that incorporated covariate information observed for these cases. This article describes an approach to modeling missing binary outcomes when there are a large number of covariates."

Factors influencing infant mortality in Vietnam

Selected determinants of overall infant mortality in Vietnam were examined using data from the 1988 Vietnam Demographic and Health Survey, and factors underlying neonatal and post-neonatal mortality were also compared. Effects of community development characteristics, including health care, were studied by logistic regression analysis in a subsample of rural children from the 1990 Vietnam Accessibility of Contraceptives Survey. Infant neonatal and post-neonatal mortality rates showed comparable distributions by birth order, maternal age, pregnancy intervals, mother's education and urban-rural residence. Rates were highest among first order births, births after an interval of less than 12 months, births to illiterate mothers and to those aged under 21 or over 35 years of age. Logistic regression analysis showed that the most significant predictor of infant mortality was residence in a province where overall infant mortality was over 40 per 1000 live births. In the rural subsample, availability of public transport was the most persistent community development predictor of infant mortality. Reasons for the low infant mortality rates in Vietnam compared to countries with similar levels of economic development are discussed.

Educational outcomes in teenage pregnancy and parenting programs: results from a demonstration

A comparison of five in-school educational and service approaches offered at seven sites in Arizona to 789 pregnant and parenting teenagers shows that except for those who enroll in a program in their third trimester, pregnant and parenting teenagers who attend a comprehensive, school-based, community-linked program are significantly more likely to continue in school than are those who have no access to a special program. The comprehensive program's impact is greatest among Hispanic students, younger students, those in grades 9-10, those who are living with their partner and those who enter the program in the first trimester. Two of the program components--strong outreach efforts and case management-are believed to have an especially favorable impact on continuation in school.

The socioeconomic consequences of teenage childbearing: findings from a natural experiment

A study based on census data from 1970 and 1980 examines the socioeconomic effects of unplanned teenage childbearing by comparing teenage mothers whose first birth was to twins with those whose first birth was to a single infant. Among black women, an unplanned teenage birth--represented by the secondborn twin--results in significantly lower rates of high school graduation and labor-force participation and significantly higher rates of poverty and welfare recipiency. Ten years after giving birth, black women who have an unplanned child are also significantly less likely than women who have not to be currently married, but are not less likely to have ever been married. Like black women, white women who have an unplanned teenage birth have significantly higher rates of poverty and welfare recipiency; they also have significantly lower family earnings and household income.

Women's labour force participation and socioeconomic development: influences of local context and individual characteristics in Brazil

We address several key hypotheses about the effects of socioeconomic development on women's labour force participation during the transition from agriculture to industrialism. To this end, we explore differences in women's labour force participation in Brazil by education, marital status, age, and urban or rural residence. We also show how socioeconomic development affects the overall level of women's participation and the differentials by education, etc. Our data are drawn from a large 1973 PNAD (Pequisa Nacional por Amostra de Domicilos) survey conducted by the Brazilian census bureau. Socioeconomic development in different parts of Brazil ranges from pre-industrial agriculture to heavy industry. Using logistic regression, we show that the general level of women's labour force participation does not change with the level of development. Highly educated women are much more likely than the less educated to be in the labour force (net of other influences); this difference is substantially greater than in post-industrial societies. Somewhat surprisingly, the influence of education is the same across the range of development levels in Brazil. Single women are more likely to be in the labour force than married women, and the difference grows during development. Age has a curvilinear relationship to labour force participation, and the old are much less likely to participate in more developed places. Rural women are slightly more likely to be in the labour force at all levels of development.