The effectiveness of antenatal care in preventing intrauterine growth retardation and low birth weight due to preterm delivery.

A case-control study was conducted to assess the effectiveness of antenatal care in preventing intrauterine growth retardation (IUGR) and low birth weight due to preterm delivery (PD), using data from 1837 births which took place in 25 hospitals in Mexico City during 1984. Women with an inadequate number of visits for gestational age had 63% greater odds of IUGR (95% CI: 1.01, 2.65) and 51% greater odds of PD (95% CI: 1.02, 2.23) than women with an adequate number. The content of antenatal visits showed no independent effect on the prevention of IUGR. Women having had poor content showed a PD OR of 1.76 (95% IC: 1.33, 2.34). An important reduction in the incidence of births with IUGR and PD could be expected if women could attend an adequate number of antenatal visits (11 and 9% reductions, respectively). Eighteen per cent of the PD births would probably be prevented if antenatal care could include at least six procedures: blood pressure, height and weight, urine and blood samples, and pelvic examination.

[Magnitude and causes of maternal mortality in the Federal District (1988-1989)]. / La magnitud y las causas de la mortalidad materna en el Distrito Federal (1988-1989).

Despite the availability of health resources to provide prenatal and delivery care for all pregnant women in the Federal District, the maternal mortality ratio is extremely high. Based on the study of all the maternal deaths which occurred in the Federal District during 1988 and the first semester of 1989 (n = 433), a ratio of 11.4 deaths per 10,000 registered live births was estimated. This is almost twice as high as the ratio reported through vital statistics. The maternal mortality ratio is higher among women delivered in public assistance hospitals as compared with those delivered in social security hospitals. This is due to the high percentage of women arriving with severe complications and to the lower standards of obstetric care in the former. About 75% of the deaths were due to one of the following causes: hypertensive disease of pregnancy, hemorrhage and infection. A detailed study of hospital records undertaken by a maternal mortality committee revealed that 85% of the deaths were preventable with the technology and resources available. The committee identified errors in medical judgment as the main factor involved in the chain of causation leading to potential preventable deaths.

[The epidemiological transition in Latin America]. / La transicion epidemiologica en America Latina.

The changes in health conditions that have occurred in most of the countries of Latin America in the second half of the twentieth century are analyzed. "This paper analyzes the main mechanisms involved in the epidemiologic transition, which are: changes in risk factors, fertility decline and improvements in health care technology." The authors use a mortality profile ratio, obtained by dividing the mortality rate due to infectious and parasitic diseases over the mortality rate due to cardiovascular diseases and neoplasms, to analyze trends in 15 countries. "Three distinct groups can be recognized. Each of them represents a different transitional experience. Such experiences are discussed in detail, including a new 'protracted polarized model' of the epidemiologic transition, which characterizes several Latin American countries. Finally, evidence is provided to illustrate the relationship among economic development, fertility change, and mortality profiles." (SUMMARY IN ENG)

Design, content and financing of an essential national package of health services.

A minimum package of public health and clinical interventions, which are highly cost-effective and deal with major sources of disease burden, could be provided in low-income countries for about US$ 12 per person per year, and in middle-income countries for about $22. Properly delivered, this package could eliminate 21% to 38% of the burden of premature mortality and disability in children under 15 years and 10-18% of the burden in adults. The cost would exceed what governments now spend on health in the poorest countries but would be easily affordable in middle-income countries. Governments should ensure that, at the least, poor populations have access to these services. Additional public expenditure should then go either to extending coverage to the non-poor or to expansion beyond the minimum collection of services to an essential national package of health care, including somewhat less cost-effective interventions against a larger number of diseases and conditions.

PIP: A minimum package of highly cost-effective public health and clinical interventions could be provided in low-income countries for about US$ 12 per person per year and in middle-income countries for about $22. This package could eliminate 21% to 38% of the burden of premature mortality and disability in children under 15 years old and 10-18% of the burden in adults. The two estimates of the package were calculated in two ways and then compared. One approach was based on the cost of specific activities, estimated from existing studies in many countries of service delivery costs by type of intervention. In the other approach, costs were estimated for a prototype district health system able to deliver the minimum package, consisting of a district hospital, health clinics, and outreach activities. In communities with moderate or high mortality, a few causes typically account for a large share of deaths. In 1990 an estimated 55% of the burden of disease was concentrated in children under 15 years old, with 660 million disability-adjusted life years (DALYs) lost. Just 10 disease conditions cause 71% of this loss. Except for congenital malformations, all these causes correspond to very cost-effective interventions, at less than $100 per DALY. Protein-energy malnutrition and vitamin-A deficiency can produce death or disability directly or through other diseases with a total loss 5-6 times larger when their indirect effect is included. The cost of the package would exceed what governments now spend on health in the poorest countries but would be easily affordable in middle-income countries. Governments should ensure that poor populations have access to these services with additional public expenditures either to extending coverage to the non-poor or to expansion beyond the minimum to an essential national package of health care, including somewhat less cost-effective interventions against a larger number of diseases.

Birthweight distributions in Mexico City and among US Southwest Mexican Americans: the effect of altitude.

In this study birthweight distributions for Mexican Americans and Mexico City were compared. Sharp differences in the two distributions were nearly eliminated by controlling for altitude. The small remaining excess in low birthweight in Mexico City appears to be due to a slight overrepresentation of tertiary hospital deliveries, and possibly to a greater prevalence of pathological conditions. The results are consistent with the favorable low birthweight rate reported for Mexican Americans and illustrate the need to adjust for altitude in studies of low birthweight.

Evaluation of maternal health programs: approaches, methods and indicators.

Evaluation of maternal health services is an essential function of any health system. Single or multiple aspects of a program can be evaluated but they must be clearly defined. To assess success of a program the dimensions of coverage, equity, quality, women's satisfaction, efficiency and cost-effectiveness must be considered. These can be measured according to some standard criteria, and various methods are described, including randomized clinical trials, randomized community trials, before and after studies, and observational studies, including the case-control approach and confidential inquiries into maternal deaths. Indicators to assess effectiveness of a maternal health program may relate to structure, i.e., available resources or organizational arrangement; process, including changes in quantity of services provided; or outcome indicators that measure maternal mortality or morbidity.

[Advances and challenges in setting priorities in health]. / Avances y retos en el establecimiento de prioridades en salud.

The advances and problems in the definition of explicit criteria to measure health needs are discussed. In part one the advantages and limitations of the retrospective and prospective approaches in the identification of health needs for a rational distribution of resources are described. In part two progress in the application of explicit criteria for the prioritization of diseases and interventions to control them are analyzed. Finally, the methodological, conceptual, and operative challenges confronted by this field are discussed.

[The epidemiologic transition in Latin America]. / La transición epidemiológica en América Latina.

The concept of health transition is considered to include two interrelated processes: transition of health care and epidemiological transition. The latter encompasses three basic processes: (a) replacement of the common infectious diseases by noncommunicable diseases and injuries as the leading causes of death; (b) a shift in peak morbidity and mortality from the young to the elderly; and (c) change from a situation in which mortality predominates in the epidemiological panorama to one in which morbidity is dominant. Latin America is characterized by a heterogeneous health profile in which different countries are in various stages of epidemiological transition. However, in most of them, the transition experience is unlike that of the developed countries and is distinguished by: (a) a simultaneous high incidence of diseases from both the pre- and post-transitional stages; (b) a resurgence of some infectious diseases that had previously been under control; (c) a lack of resolution of the transition process, so that the countries appear to be caught in a state of mixed morbidity; (d) a peculiar epidemiological polarization, not only between countries but also in the different geographical areas and between the various social classes of a single country. This experience is called a "prolonged polarized model."

[Elements for a theory of transition in health]. / Elementos para una teoría de la transición en salud.

This article presents the basic elements for developing a theory of the health transition. Such elements include the definition of concepts, the specification of a framework on the determinants of health status, the analysis of the mechanisms through which changes in health occur in populations, the characterization of the attributes that allow us to identify different transition models, and the enumeration of the possible consequences of the transition. The propositions are presented with a sufficient level of generality as to make them applicable to different contexts; at the same time, an attempt is made to provide them with the necessary specificity to account for different national experiences, thus opening a space for future comparative research efforts. Through the systematization exercise presented in this paper, we hope to contribute to the progress of a topic that has gained growing importance during recent years. Such importance is due to the enormous potential that health transition theory has for understanding and transforming the growing complexity of our times.

[Curricular design of health postgraduate programs: the case of Masters in epidemiology]. / Diseño curricular de programas de posgrado en salud: el caso de la Maestría en Epidemiología.

This paper discusses the need to create specific programs for the training of researchers in epidemiology, a field that has traditionally been ignored by the graduate programs in public health. This is due, in part, to the emphasis that has been placed on the training of professionals in other areas of public health. The paper also includes the results of a consensus exercise developed during the curricular design of the Masters Program in Epidemiology of the School of Medicine of the National Autonomous University of Mexico. The technique used during the consensus exercise was the TKJ, which allows the presentation of ideas and possible solutions for a specific problem. This is probably the first published experience in the use of such a technique for the design of an academic curriculum. Taking as a base the general characteristics of the students, the substantive, disciplinary and methodological subjects were chosen. The results showed a need for a multidisciplinary approach based on modern methodologies of statistics and epidemiology. The usefulness of the results of the curricular design and the superiority of this method to reach consensus is also discussed.

Elements for a theory of the health transition.

This article presents the basic elements for developing a theory of the health transition. Such elements include the definition of concepts, the specification of a framework on the determinants of health status, the analysis of the mechanisms through which health change occurs in populations, the characterization of the attributes that allow us to identify different transition models, and the enumeration of the possible consequences of the transition. The propositions are presented with a sufficient level of generality as to make them applicable to different contexts; at the same time, an attempt is made to provide them with the necessary specificity to account for different national experiences, thus opening a space for future comparative research efforts. Through the systematization exercise presented in this article, we hope to contribute to the progress of a topic that has grown in importance during recent years. Such importance is due to the enormous potential that health transition theory has for understanding and transforming the growing complexity of our times.

Early neonatal mortality and cesarean delivery in Mexico City.

The relationship between cesarean delivery and neonatal mortality is presented with information from 292 early neonatal deaths (cases) and 3098 survivors (controls) born in 25 hospitals in Mexico City during the summer of 1984. The overall rate of cesarean delivery was 27%. Variations between health agencies and different social groups were not related to obstetric risk, suggesting that a sizable proportion of the operations were probably unjustified. Babies of normal birth weight (greater than or equal to 2500 gm) delivered by cesarean section were 2.5 times more likely to die in the early neonatal period compared with vaginally delivered babies of the same weight. The excess of mortality could not be explained by the effect of maternal characteristics or complications or by differences in birth weight or gestational age. It is suggested that the conditions under which the operation was performed probably explain the increased risk of early neonatal death. It is likely that poor quality of resuscitation and respiratory care are implicated in the link between "unnecessary" cesarean section and early neonatal mortality.

[Relationship between reproductive patterns and infant mortality: alternative interpretations]. / Relación entre patrones reproductivos y mortalidad infantil: interpretaciones alternativas.

A secondary analysis of the data of the Mexican National Fertility and Health Survey of 1987 (ENFES for its spanish acronym) was undertaken in order to study the relationship between reproductive patterns and child mortality. A total of 13,216 births and 711 infant deaths occurred 1 to 15 years previous to the survey were studied. The main conclusions are: 1) it is the adverse social, economic and environmental conditions surrounding young mothers (15 to 19 years) which are responsible for the excess mortality found in their children; 2) children of older women (35 and more years) experience increased mortality only in the late fetal period, this suggesting that a biological mechanism is mainly at stake; 3) the relative risks of death of first births, as compared to subsequent ones are generally smaller than one, indicating that first births have a lower probability of dying. The relative risk of death of first born relative to subsequent births, on the other hand, decreases with increasing age at death, suggesting that biological factors such as low birthweight and intrapartum complications are possibly important as well; 4) relative risks of death for short-spaced as compared to well spaced births were found, in general, to decrease from the late fetal to the neonatal and to the postneonatal periods. This points to a biological pathway, possibly via maternal nutrition, for the effect of spacing on child mortality.

[Limitations of infant mortality as a health indicator]. / Limitaciones de la mortalidad infantil como indicador de salud.

Infant mortality is usually accepted as a sensitive indicator of living conditions, and of the coverage and quality of health care in a specific country. However, the validity of this indicator in middle-income countries presents some important limitations. First, underegistration of infant deaths is a common feature. In second place, the national figures hide the great inequalities that may exist among different social sectors and regions. In this paper, the limitations of Mexico's infant mortality rate are analyzed. Underegistration is demonstrated by comparing infant mortality rates obtained from vital statistics data and national health surveys. Differences among social sectors are evident when specific infant mortality rates are compared. Inequalities have been increasing in the last years.

[A database for research in public health]. / Base de datos para la investigación en salud pública "BISP".

Epidemiological and health system research projects are often delayed due to the difficulties to build validated data basis in personal computers. This papers presents a new computer interactive program for handling numeric data from a given questionnaire to a structured archive. The questionnaire includes the basic variables of the dwelling and of the members of the household. A list of sociodemographic and health variables are selected, although other variables can be easily added, according to special needs. All the intermediate steps regularly needed to construct a data base are included in the package: capture, verification, validation and record linkage. The package is equipped with the basic procedures needed to produce tabulations and basic statistical analysis.

[Postneonatal mortality caused by diarrhea: a case-control study]. / Mortalidad postneonatal por diarreas: un estudio de casos y controles.

A matched case-control study was undertaken in Naucalpan de Juárez, Estado de México. The goal of this study was to identify the risk factors for diarrheal disease in children between seven days and one year of age. We identified 63 case and 188 controls. The most important risk factors were: mother's age greater than 36 years with an odds ratis (OR) 3.7, lack of breastfeeding (OR 11.3), breast and bottle feeding (OR 5.4), lack of intradomiciliary sewage (OR 8.3), repeated episoded of disease (OR 8.6) and father's consumption alcoholic beverages (OR 3.6). The main possible paths by which these factors influence mortality are discussed. Specific interventions for some of the factors are proposed.

[Evaluation of literature published about research on perinatal health carried out in Mexico, 1980-1988]. / Evaluación hemerográfica de la investigación en salud perinatal realizada en México, 1980-1988.

In this paper, the authors present an analysis of the quantity and quality of Mexican literature on perinatal health, corresponding to the period 1980-January 1989. The articles here analyzed were published in journals of the Index Medicus. First, the authors established the Mexican contribution to the international bibliographic production. After that, the articles were classified according to the subject under discussion. The relevance of these themes, in relation to the Mexican epidemiologic situation, is discussed. In second place, a preliminary evaluation of the quality of some of the national articles was done. With this purpose, a scoring system (including conceptual and methodological criteria) was elaborated. The authors concluded that Mexican scientific production on perinatal health is still very scanty and they observed that it diminished during the present decade. One possible reason for that is the reduction of the budget devoted to research and the scarcity of researchers salaries. The analysis by themes showed that the scientific production is spread out and that the subjects most frequently treated do not always correspond to the most important epidemiologic problems in Mexico. The evaluation of quality is considered by the authors as preliminary. Anyway, this first approach shows that most of the papers are based on research projects with a transversal design, without an explicit theoretical framework and focused on hospital settings. The authors conclude that the evaluation of the quantity of the scientific production contributes to research development. Perinatal health; analysis of research.