The use of sterilization as a method of contraception is increasing rapidly throughout the world. This paper reports on sterilization rates for women in Colombia, Costa Rica, the Dominican Republic and Panama in relation to demographic characteristics. Comparisons are made with non-sterilized women using other efficient contraceptive methods.

The sterilization rates range from 0·161 in Colombia to 0·552 in Panama; births averted are calculated as one-quarter in Colombia, one-half in Costa Rica and one in the Dominican Republic and Panama.

This study examines data from 15,172 episodes of hospitalization pertaining to Aboriginal Australians discharged from public and private hospitals in New South Wales during 1978. Morbidity patterns revealed provide quantitative evidence on a whole population basis for the often impressionistic statements of those dealing with limited areas or with specific diseases.

Respiratory diseases are by far the most common and their occurrence seems to be out of proportion in relation to other diagnoses. Gastrointestinal and diarrhoeal diseases are important among young children, alcoholism among men, and diabetes among older people of both sexes. The most common surgical procedures involved abdomen, female genitals and ear, nose and throat.

It was noted that for most disease categories Aborigines were more likely to be hospitalized than non-Aborigines, the major exception being neoplasms. On the other hand, Aborigines were significantly less likely to be hospitalized for surgical operations. Overall, Aborigines were found to suffer higher levels of ill-health primarily due to their depressed economic conditions and social exclusion as well as racial discrimination to which they are commonly subjected in Australia.

Seventy women with rhesus isoimmunization, referred to hospital in Newcastle upon Tyne, when compared with the overall hospital population, showed an excess of pregnancies by more than one partner. By comparing them with a control group it was demonstrated that the differences in marital pattern were explained in terms of age, parity and social class. One or other parent of babies affected by haemolytic disease of the newborn was more likely than controls to undergo subsequent sterilization.

The mean size of sibship in which children are reared is greaterthan the mean number of children born to those children's parents' generation. In this paper, family size is considered from the child's point of view, and estimates made of how many siblings (and some other relatives) children have, using data from a survey carried out in Great Britain in the late 1960s. The size of the ‘family’ experienced by children is largerthan may at first sight appear. For example, women who married in the period 1941–55 onaverage had 2·2 children, but these women's children grew up, on average, in sibships of3·5 children; 38% of them grew up in a family with four children or more. Moreover, on average, these women's children had six uncles and aunts and possibly twice that number of first cousins. More than half of the children had at least one parent who was brought up in a family with six children or more and almost one in five had at least one parent who came from a family with ten children or more.

The average gains in life expectancy and in working life ages for Koreans in Japan and Japanese are examined when four selected causes of death are hypothetically eliminated. The life expectancy at birth of Korean males and females in Japan (1974–76) was 67·1 and 77·1 years, respectively. The largest increases in life expectancy at birth for Koreans in Japan and Japanese (both sexes) result when cardiovascular diseases are eliminated. At the working ages, 15–65 years, of Koreans in Japan and Japanese (both sexes) the largest gains result from elimination of malignant neoplasms. The implications of the results are discussed in relation to the public health services and acculturation of Koreans in Japan.

One hundred and thirty healthy women who were willing to breast-feed their babies were followed during the first postpartum year to assess their fertility, lactation and bleeding pattern and examine possible relationships between these variables. Seventy-five women were in full nursing and 22 in partial nursing at the end of the 6th postpartum month. Five hundred and three woman-months and nine pregnancies were recorded during full nursing between the 2nd and the 6th month after delivery. The cumulative probability of pregnancy at the end of 6 months in all full nursing women and in non-amenorrhoeic full nursing women was 10.0% and 27.2% respectively. The corresponding figure for partial nursing women was 40–5%.

By the end of the first year, the cumulative probability of pregnancy in full nursing women had increased to 33.9%. Except for the bleeding pattern, no differences were found among full nursing women who did or did not become pregnant.

It was concluded that full nursing women living in an urban setting who want to space pregnancies need additional protection at a time that depends upon the level of assurance wanted.

The paper explores the social and demographic factors that influence fertility in Sri Lanka since the second world war employing multiple regression analysis, and how these factors change with time. The dominating contribution made by female proportions currently married in the age group 20–24 in explaining fertility variation is emphasized.

The widespread availability of effective means of fertility control in many developed countries has made voluntary childlessness a viable alternative to parenthood. Little attention however has been given to the family planning requirements of those who take this minority decision. Data from Scotland suggest that the voluntarily childless have contrasting needs and that usage of and perspectives on contraceptive techniques, sterilization, and abortion depend primarily upon the extent and basis of individual commitment. It is important that those involved in providing family planning services should be aware of the variations in the childless condition and how these might influence individual behaviour in relation to fertility control.

A survey of 600 married couples in the Irish Republic in 1975 found marked pronatalist attitudes and an overall mean family size of 3·1 children, ranging from 1·1 children for couples with marriage duration of less than 5 years to 5·1 children for couples married for 15 years or longer. Husbands and wives had the same viewson the ideal size for the average family—5·6 children; this is considerably higher than other European survey findings. Overall, 66% of wives said that they had used some formof contraception and this correlates highly with social class, age of wife, educational level and residence. Use of the pill correlates with residence and age but not with social class or education. One-third of the sample would like more information on the subject of family planning. Although very few gave religious attitudes as a reason for not using birth control in general, 13% stated that the pill was immoral.

A sample survey was conducted in South Carolina to determine how income and education relate to hypertension, independently of age, race and sex. The results indicated that there was a significant inverse relationship between income and hypertension for Whites (P < 0·0001), but not for Blacks. There was also a statistically significant inverse relationship between education and hypertension for Whites (P < 0·0001) and for Blacks (P < 0·001).

Births to women aged 35 years and older are compared with births to women aged 20–34 in three hospitals, one each in Mexico, Egypt and Hungary. In the two developing countries, babies born to the older women had lower rates of survival until hospital discharge, and were more likely to have depressed 5-minute Apgar scores. They were not, however, more likely to be of low birth weight. The differences were statistically significant, and remained when several other variables were controlled. The variables controlled were known to be age-related and to influence pregnancy outcome.

Hungary, the only developed country in the analysis, was quite different. Age had a significant influence on the weight of the infant, but not on survival or Apgar score. It seems therefore that when older women are in general good health and there are no concurrent social risk factors, advanced maternal age does not necessarily increase the risk of an adverse pregnancy outcome.

In rural women in Andhra Pradesh, major determinants of early menopause are poor health status, particularly low haemoglobin and protein levels, increased parity, and pathological conditions including infection by bacteria, fungi and viruses. Early menopause leads to increased likelihood of extramarital sexual relations by husbands, resulting in family disharmony. As remedial measures, a greater age difference between prospective spouses, education in sexual hygiene, improvement of health and nutritional status, and limitation of conception are indicated.

A study has been made of twinning rates throughout the world over the last two decades. There has been a decline in age-specific dizygotic twinning rates in almost all of the developed countries during this period. Exceptions to this trend are provided by the United States, where the only decline in twinning rates in the last two decades was in births to older women in the 1960s, and by Czechoslovakia, Hungary and Bulgaria, where an initial decline in twinning during the 1960s was followed by stable twinning rates.

It is suggested that the cause may be some form of environmental pollutant, perhaps a pesticide, which has been the subject of restrictive legislation first in the United States and later in the three Communist countries. Possibly the cause of this decline may be identified by a study of such legislation.

This seems to be the first study of twinning rates in Central and South America. The low twinning rates in some of the countries there may indicate the genetic affiliations of their inhabitants with those (of Mongoloid origin) of countries in the Far East.

The success of screening programmes for cancer will depend greatly on public attitudes if sufficiently high levels of participation are tobe attained. The aimof this study was to identify major independent dimensions of public attitudes to cancer through factor analysis of responses to interview questions using a representative population sample. Data were collected by questioning a random sample of 500 persons aged 18 or over in Canberra on their attitudes to and knowledge of cancer and experience of the disease in others knownpersonally to them. Subjects with the disease were excluded. Factor analysis showed four relatively independent attitude dimensions: anxiety about cancer, denial of the threat of cancer, fatalism about prevention and fatalism about control. Item analysis and inter-scale correlations confirmed the internal coherence and relative independence of these dimensions, except that the latter two showed a moderate positive correlation. It is suggested that cancer education and promotion of screening should deal separately yet concurrently with these four attitudes toachieve best effect.

With the increase in labour force participation by wives and mothers in the United States, family roles of modern women are becoming increasingly complex. As mother/provider, women are faced with problems in planning their lives to accommodate their modern roles. Three variant lifetime patterns of fertility and employment are identified in a study of second-generation Japanese American women, a group which has experienced high rates of labour force participation. Analysis of socio-economic background factors suggests that these patterns are alternative modes of integrating the complex lifetime demands on women in the modern world.

Information is collected from the literature on the age at which British children were weaned from the breast between 1500 and 1800. The weaning age recommended by ‘professionals’ was compared with that said by contemporaries to be common, and with those found in a sample of 42 children. A significant decrease was found in the length of suckling particularly after 1750; this was possibly related to the availability and social acceptability of artificial feeding, an increase in the incidence of maternal suckling among upper and middle class women, and the effects of industrialization. The reason for weaning was individual to each nursing couple; no significant difference was found between the weaning age of males and females, or between wet nursed and maternally breast-fed infants; the weaning age within families was not significantly different from a sample of unrelated children within the same period. Between 1650 and 1800 the weaning age recommended by medical writers was apparently representative of actual practice.

Regression surface analysis was used to examine relationships between sibling variables and measures of cognitive performance at different levels of family environment measures, for children from different Australian ethnic groups. Included in the sample were 460 Anglo-Australian, 170 Greek, and 120 Southern Italian families. Each family had an 11-year-old child and interviews with parents related to those children. There were no associations between the sibling variables and intellectual ability scores. For word-test scores the findings provided some tentative support for an admixture explanation of sibling correlates of children's cognitive performance. Generally, the study revealed that at different levels of family environment dimensions, sibling variables had few associations with various cognitive measures for children from different ethnic groups.

The estimation of genetic similarity from correspondence of surnames (isonymy) allows investigation of historical population structure. This study uses surname data from seven isolates located along the west coast of Ireland during the 1890s to assess geographic and historic influences on population structure. Observed genetic variation among populations shows a close fit with the expected isolation by distance model, with estimated parameters of isolation and migration being similar to those obtained in other studies of isolated populations. Local genetic variation appears to be due primarily to the size of the local breeding population, with deviations being explained in terms of recent emigration.