Search

Resumen Las tasas de cesarea han aumentado de manera constante en la mayoria de los paises de medianos y altos ingresos en los ultimos decenios sin justificacion medica. La solicitud materna es uno de los factores no medicos citados con frecuencia que contribuyen a esta tendencia. El objetivo de este documento es realizar una revision de la bibliografia actual sobre las preferencias maternas por la cesarea.

Blood pressure is a major cause of premature death, but few large studies of Hispanic populations exist. Between 1998 and 2004, a prospective study in Mexico City recruited 100,000 women and 50,000 men, and has followed cause-specific mortality electronically.

Information on the association between exposure to beta-hexachlorocyclohexane (beta-HCH), hexachlorobenzene (HCB) or polychlorinated biphenyls (PCBs) and the incidence of breast cancer is inconclusive. However, exposure to such compounds is a public health concern in Mexico and is subject to recent regulation. Serum levels of beta-HCH, HCB and PCBs were analysed in 95 histologically confirmed breast cancer cases and 95 hospital controls, 20-79 years of age, from Mexico City, enrolled between March 1994 and April 1996. After adjusting for established risk factors, there was no evidence of a relationship between beta-HCH, HCB and PCBs and breast cancer risk (OR for beta-HCH tertile 3 versus tertile 1: 1.05 95% CI 0.46-2.40; OR for HCB tertile 3 versus tertile 1: 0.46 95% CI 0.20-1.07; OR for PCBs 1.31 95% CI 0.33-5.21 for the high category of exposure). This study lends no support to the case for a role for beta-HCH, HCB or PCBs in breast cancer aetiology.

The work climate (WC) affects the performance of service providers and has an impact on the care provided to users. This is important in the case of conditions that affect the quality of life, as is the case of chronic kidney disease (CKD) treated with haemodialysis. In Mexico, the demand for the care of CKD cases is increasing and the haemodialysis offer is limited. The purpose of this study was to describe and compare the WC in public, private and social security haemodialysis units in Mexico and to validate a tool to measure WC in haemodialysis units (HU).372 professionals from 84 HU in 27 states were interviewed using a questionnaire. This included questions about the WC, quality of care and structure and organisation of the HU. Variables were compared by type of institution and profession.Significant correlations were observed between the WC and indicators of the quality of care. Nine out of fourteen variables presented important differences by type of unit, with a better perception of WC in private units and a poorer perception in social security ones.The perception of WC relies on the organisation and planning of the institutions, as well as on their infrastructure. In the case of Social Security HU in Mexico, these appear to be the areas that require improvement in order to encourage a better work climate.

To evaluate the modes of detection of breast malignancies in Mexico City and to estimate the number of patients diagnosed in advanced stages.This cross-sectional study was conducted between 1994 and 1996, among 256 women with a histological diagnosis of breast cancer, at three tertiary level public hospitals in Mexico City. Personal interviews were conducted to collect data on reproductive characteristics, clinical history, and breast cancer modes of detection. Data analysis consisted of percentages, odds ratios, and 95% confidence intervals.Ninety percent of women sought medical care after identifying a breast lump by themselves. Only 10% of patients had a stage-I tumor; all 27 cases first identified by a physician were in stage II-B and higher.An increasing trend of breast cancer mortality in Mexico City will persist, unless a greater proportion of tumors in situ is detected; this would require enhancing breast cancer screening programs and conducting an intense educational intervention among women at risk.

To assess the impact of occupational exposure to noise, as well as its relationship with other factors that can induce hearing loss.In January and February 1997, we conducted sonometry and dosimetry tests in a cement factory, as well as audiometric test in 85 cement workers, to identify sources of noise and evaluate the effect to noise exposure and other factors, of the prevalence of occupational hearing loss. Statistical analysis was conducted using measures of central tendency, bivariate analysis and polynominal regression models.High noise levels were found in the crushing, crude milling, and cement milling sites. The highest individual dose corresponded to the packer job post. Fifty-five per cent of the study population presented some degree of hearing loss due to noise exposure. The cement processing area with the highest percentage of damaged workers was calcination.Our results show that noise is a serious risk factor in particular sites of cement factories, and also that an elevated number of hearing loss cases are due to occupational noise exposure in this industry; Our findings underscore the need for designing and implementing hearing protection programs, to assure the health and safety of cement workers.

The present work pretend to describe the development achieved in the field of health technology assessment and to propose a set of criteria to evaluate them, with the intention that it will lead to the development of health programs and policy with a tendency to maximize effectiveness, efficiency and quality, within a frame of increasing needs and scarce technical and economic resources for health care. For this work, a comprehensive review was carried out about the background of health technology adoption in our country, and the context by which to evaluate the accessibility and utilization of the health technology. In the section for technology assessment, it is propose a method to evaluate based upon the natural history of disease, that is, the traditional form of health assessment is restricted to a cross section in time (vertical evaluation), and in this study the authors propose a model with a horizontal approach, that should offer as its main virtues the development of guidelines with regards to prevention, diagnosis and treatment, in addition to cost containment, in support to a more effective and higher quality medical practice.

To develop an effective strategy to inform Mexican women between 12 and 47 years of age about breast cancer (BC) and train them to perform breast self-examination (BSE).Between April, 1996 and July, 1998, two different strategies to teach BSE were designed and evaluated in Cuernavaca, State of Morelos, Mexico. These strategies included teaching materials and were based on opinions of women participating in the first stage of this study. Both strategies consisted of the presentation of a leaflet and a video. The first strategy was delivered by a public health nurse in charge of leading the session. The second one was presented by a BC survivor. This second strategy included slides and silicon breast models. These two strategies were then compared to a third one, consisting of a primary care nurse handling out a leaflet and showing a video, based on Health Secretariat's guidelines. In total, 149 women were trained. They were randomly assigned to any one of these three strategies. The effectiveness of the teaching strategies was determined by assessing the changes in the women's knowledge of BC and BSE, as well as in their ability to identify the largest number of lumps on a natural size silicon breast, before and after training. Statistical analysis included Student's t test, variance analysis, McNemar's chi 2, Pearson's chi 2, and multiple linear regression.With all three strategies, there was an increase of approximately 30% in women's knowledge of BC and BSE as well as in their ability to detect lumps. Although at the beginning of the training only one out of every 20 women were able to identify more than three lumps in the silicon model, by the end between 3 and 4 of every 10 women were able to do this, with values of p0.05. Some factors determine women's learning of both BSE and information about BC as well as their ability to identify lumps.Teaching BSE with any of the strategies evaluated could be included in an integral program to educate Mexican women on breast cancer prevention and early detection. The appropriate and monthly practice of BSE is linked both to a decrease in the amount of time elapsing between the identification of suspect signs and the demand for medical care, such as requesting a clinical breast examination, which entails identifying small tumors when BC is present.

In this paper we review a hypothesis put forth in 1980 by James Fries under the name of the compression of morbidity, as an example of theoretical development in the field of epidemiology. Initially we discuss some of the essential features of scientific theories and make a historical account of the most important causal models that epidemiology has embraced. Then, the basis for proposing that a compression of the morbidity is taking place are described focusing on its advantages and limitations when it is analyzed from the point of view of structuralism. Finally, we conclude that, to the extent that they are correct, models of this kind have the potential of describing and predicting the evolution of human health; hence, their systematic development entails an extraordinary importance for public health.

To determine the prevalence of lactation, the use of industrialized milk and weaning, and the factors related to lack of breast-feeding and early weaning in young infants of rural communities.Transversal study performed by last year medical students doing Social Service in 222 rural communities in Mexico who applied structured interviews to 5,409 families with children younger than 1 year of age.The percentages of children who were never breast-fed were: in the north (N) 21.4%, in the center (C) 7.6% and in the south (S) 5.3%. Children who were still being breast-fed, either exclusively or with mixed feeding by the third trimester were 35.6% (N), 67.6% (C) and 77.5% (S); in the second trimester, 67.2% (N), 40.9% (C) and 51.6% (S) had been weaned. In the N region it was observed that lack of breast-feeding was associated to the health personnel who attended delivery, mothers with six or more years of education and less than four children, dwellings with permanent material floors, two or more household commodities and a head of the family different from the father. Early weaning was essentially associated to the same factors; additionally, to the child being taken care of by someone different from the mother, artificial lactation by parental decision or due to medical recommendation and the use of health services provided by social security or private physicians.Artificial lactation and early weaning are typical of small families, with high educational level of the mother, better living conditions and contact with medical personnel, especially in the N of the country. Children are weaned before the second semester of life and it is therefore deemed necessary to implement health programs which promote breast-feeding and gradual weaning after the sixth month of life among the infant population of Mexican rural communities.

Some, but not all, epidemiological studies have suggested that dichlorodiphenyltrichloroethane (DDT) may play a role in the development of breast cancer. These investigations have been conducted in countries where this substance has been banned for at least 20 years. We conducted a study in Mexico, a country in which DDT is still being used to control malaria. In a hospital-based case-control study, we compared 141 histologically confirmed cases of breast cancer with 141 age-matched controls (+/-3 years). All subjects were identified at three referral hospitals of Mexico City between March 1994 and April 1996. Reproductive histories and other variables were obtained by structured interviews, DDT/DDE levels were determined in serum by gas-liquid chromatography. The arithmetic mean of serum DDE in lipid basis was 562.48 +/- 676.18 ppb (range, 10.24-4661.44) for the cases and 505.46 +/- 567.22 ppb (range, 0.004 to 4361.75) for the controls, but this difference was not statistically significant. The age-adjusted odds ratios for breast cancer regarding the serum level of DDE were 0.69 (95% confidence interval, 0.38-1.24) and 0.97 (confidence interval, 0.55-1.70) for the contrasts between tertile 1 (lowest level) and tertiles 2 and 3, respectively. These estimates were unaffected by adjustment for body mass, accumulated time of breast-feeding and menopause, and other breast cancer risk factors. These results do not lend support to the hypothesis that DDT is causally related to breast cancer at the body-burden levels found in our study population but do not exclude the possibility that higher levels of exposure could still play a role in the etiology of this tumor.

In this paper we propose a wider scope for public health surveillance in order to incorporate demographic and health systems monitoring along with activities conventionally associated with epidemiologic surveillance. This new conception stems, in turn, from a revised definition of public health, which describes--not a sector of activity or a type of health service--but a level of aggregation based on the population at large. In our review of the ideas that lead to the institutionalization of health surveillance, we stress the broad concepts developed by such pioneers as Graunt and Petty. Their original concepts emerged from their active concerns for the public's health at a time when no scientific theory of contagion was available--let alone any knowledge about how to treat persons for the major diseases that affected them. Later on, and largely as the result of impressive advances in biomedical knowledge, surveillance activities tended to specialize and to concentrate predominantly on disease outbreaks and on salient adverse health conditions. Health surveillance became closely associated with epidemiologic surveillance, which in turn became associated with the ability to respond promptly to adverse health outcomes. Recently, we have witnessed a gradual broadening of both the concepts and the practice of health surveillance. Paradoxically, the newer proposals tend to recapture part of the spirit and scope of earlier definitions, prompted perhaps by such thoughtful historic parallels as the newly emerging health problems for which we have no clear-cut solution. If one element has to be stressed to promote the objectives of health surveillance today, it is the need to anticipate health outcomes and not just respond to them. This, in turn, requires an increased attention to the surveillance of risk factors, and a greater understanding of the complex causal relationships that those factors--including behavioral, lifestyle, and environmental ones--with adverse health outcomes and disability. Needless to say that, the first and foremost aim of health care--and of modern surveillance--is to promote the well-being of individuals by improving their health.

In this paper, we have proposed a wider scope for public health surveillance in order to incorporate demographic and health-system monitoring, along with activities conventionally associated with epidemiologic surveillance. This new conception stems, in turn, from a revised definition of public health, which describes, not a sector of activity or a type of health service, but a level of aggregation based on the population at large. In our review of the ideas that lead to the institutionalization of health surveillance, we have stressed the broad concepts developed by such pioneers as Graunt and Petty. Their original concepts emerged from their active concerns for the public's health at a time when no scientific theory of contagion was available, let alone any knowledge about how to treat persons for the major diseases. Later on, largely as the result of impressive advances in biomedical knowledge, public health surveillance tended to specialize and to concentrate predominantly on disease outbreaks and on salient adverse health conditions. Health surveillance became closely associated with epidemiologic surveillance, which in turn became associated with the ability to respond promptly to adverse health outcomes. Recently, we have witnessed a gradual broadening of both the concepts and the practice of health surveillance. Paradoxically, the new currents tend to recapture some of the spirit and scope of the early definitions, prompted perhaps by grave historical parallels--we face newly emerging health problems for which we have no clear-cut solutions. If one element needs to be stressed to promote the objectives of health surveillance today, it is that we need the ability to anticipate health outcomes and not just respond to them. This, in turn, requires that we give more weight to the surveillance of risk factors and that we increase our understanding of the complex causal interrelationships that link exposure to risk factors--including behavioral, life-style, and environmental ones--with adverse health conditions and disability. Needless to say, the first and foremost aim of health care--and modern surveillance is one of the tools needed to achieve this aim--is to promote the well-being of individuals while improving their health.

Previous studies have emphasized the impact of alcoholism on public health, especially on the incidence of liver cirrhosis, which ranks among one of the main causes of death in Mexico. Accordingly, the epidemiologic features of liver cirrhosis mortality (LCM) are examined, highlighting its historical trends, its geographical distribution and other risk factors like age and sex. The data show a consistently high LCM rate over time, male rates moving slightly up and female rates down. Proportional mortality has been increasing. The significant risk increment with age has determined LCM to be the leading cause of death for both sexes in the 30-64 years age group. A particularly interesting finding relates to the continuous excess of LCM seen in Mexico City and four surrounding states; on the contrary, in the northern states, LCM is considerably low. This difference is valid for women too. Comparing all states, a gradient of LCM rates from high to low mortality areas is observed. The social and health implications of LCM regional distribution demand the conduction of epidemiological studies to identify possible explanatory variables related to the pattern of alcohol consumption or other risk factors. Nonetheless, these data alone justify the implementation of an effective action plan in the high-risk areas to deal with this health problem, inherently associated with individual and social behaviors.

Over the years high cirrhosis mortality rates have been reported in Mexico City and in the surrounding states (Hidalgo, Tlaxcala, Puebla and the State of Mexico); on the contrary, well defined areas, such as the northern states, have shown a considerably lower mortality rate. This situation may indicate that some factors such as the pattern of alcoholic intake and other environmental characteristics could explain this striking difference. To determine the role of alcohol, the availability and consumption of alcohol at regional and state level were compared with cirrhosis mortality rates. A high and statistically significant correlation was found with pulque availability and consumption (r = 72-92%, p less than 0.01) in all periods of time under examination. On the contrary, a statistically significant negative association was observed with beer consumption and a positive, but not significant correlation, with distilled alcoholic beverages. Infectious hepatitis incidence, prevalence of exclusive use of native languages (as an indirect index of ethnic background) and nutritional deficiencies were also studied as possible risk factors. Nutritional deficiencies and the prevalence of exclusive use of náhuatl and otomí languages were positively correlated. These results can be useful to conduct further epidemiological studies still needed to determine the etiologic role of pulque consumption as well as of the other risk factors. Nonetheless, the current data stress the need to implement public health programs to reduce alcohol consumption, especially pulque, and to minimize the impact of these risk factors in high mortality areas.

A cross-sectional study was conducted in order to know the prevalence of hypertension and some characteristics related as age, sex, obesity, smoking, heredity and exercise, in a mexican population; their possible causal role is discussed. Other variables related with the treatment and control of hypertension were explored as the awareness of personal blood pressure figures and regularity of treatment among hypertensives. The global hypertension prevalence was 26.9% (CI 95% 24.0-29.0), male's prevalence was 33.7% (CI 95% 29.0-38.0) and female's prevalence was 24.3% (CI 95% 22.0-27.0). Age, sex, obesity and heredity were the most associated characteristics on systolic and diastolic mean figures. The Prevalence Odds Ratios (POR) were 1.79 (CI 95% 1.4, 2.29) for obesity; for smoking 1.41 (CI 95% 1.1, 1.82), heredity 1.23 (CI 95% 0.92, 1.64), and sport practice 0.95 (CI 95% 0.64, 1.39). Among population studied only 61.1% knew their habitual blood pressure figures, and among known hypertensives only 27.1% were on regular anti-hypertensive treatment.

It is well known that in developing countries, measles disease is frequently increasing among adolescents. In Mexico, it is also thought that this problem is moving in such a way; however, this can not be proven with the statistical information at hand. For this reason a serum-survey was carried out in a sample of 870 healthy teenagers drawn from public and private secondary schools in Mexico City, in order to know if they were susceptible to measles disease and in that way make the right decisions. The information background related to the vaccination and information about previously having the disease was obtained from a questionnaire that was given to the parents of the studied teenagers. In order to get de immune state of the studied group, measles antibody titles were quantified using the ELISA technique. The findings shown that the susceptibility in this group was of 21.4%, which is certainly higher than the ones that have been found in some other countries where measles epidemics in people at this age have been well documented. Accordingly, it is thought that the displacing of this illness can be found in teenagers of Mexico City. An association was found with male sex and having the illness before. Teenagers that studied in public secondary schools reported more frequently, they had had the illness than the ones who studied at private schools. It was also found that these teenagers had a higher probability of having antimeasles antibody titles which are considered non protective; that is why it is thought these students are more likely to become ill during the adolescence stage than those who already have had the illness and the consequent protection.

This paper presents the results of an ecologic study of the trends of ischemic heart diseases (IHD) (ICD 9th 410-414) from 1950 to 1985 in Mexico. The mortality rates area strongly related with age and sex. Among those aged 30 to 59 years old, the male-female ratio (MFR) was 2.5 whereas in those aged 60 or more the ratio was 1.2. The mortality rates for IHD increase over time, particularly when converted in logarithms (r = 0.89). There were important differences in the regional mortality patterns by age and gender. Among males the northern region showed a mortality risk 2.5 times higher than the southern region; this risk increases (3.0) in those older than 60 years old. The increasing risk modifiable risk factors such as smoking, cholesterol and hypertension.

The main aim of this study was to assess the quality and quantity of the Mexican epidemiologic production published in two journals: Salud Pública de México (SPM) and Boletín de la Oficina Sanitaria Panamericana (BOSP). A previously accepted criterion was used to qualify a paper as an epidemiologic work. The period of study was eleven years (1975-1985) with 89 classified paper as "epidemiologic reports" (36 of BOSP and 53 of SPM). The variables included: original or revision's report; epidemiologic design; measures employed (frequency, association or potential impact); condition (contagious diseases, chronic-degenerative diseases or physiologic status); use of prevalent cases, incident cases or deaths; internal and external validity; bias' recognition; and number of references. Among the results that stand out are the proportion of cross-sectional designs (51.75), the weight for communicable diseases (36%), the detection of potential bias (65.7%) and the reports without references (30%). The discussion is centered in the main implications of these results when they are used to make decisions in the planning, operation and assessment of health services and in the generation of new epidemiologic knowledge.

The results of a study about mortality by tetanus in Mexican children under one year of age, during the 1970-1982 period, are reported. This age-group was subdivided in three, as follows: perinatal (less than 7 days), neonatal (less than 29 days) and postneonatal (29 to 364 days). Mortality by tetanus in children under one year of age showed a decreasing trend during the mentioned period, and this was most pronounced from 1979, because of changes in the codification of mortality by tetanus in this group of age. On the other hand, it was found that the greatest proportion of deaths by tetanus happened in the under one year of age group, and particularly in the neonatal group (less than 29 days). The geographic distribution of tetanus in Mexico was studied later, and showed a predominant incidence of the disease in coastal states of the country; an additional finding in this investigation was the displacement of the disease from the Pacific strip to the Gulf of Mexico. Finally, the mortality differentials by sex were studied, and showed that males were the most affected in the three age groups. We cannot explain this finding at the time.

During health care services planning, rational and coherent information is required in order to allocate resources in accordance with local relative need. In an attempt to recognize the national condition, Stone's method was used. This is a semi-quantitative method for analysing the relationship between health care resources and need. Years of potential life lost index was used for need assessment among the states, and confronted to its Federal Public Health Investment. The optimum resource/need ratio is regarded as that pertaining to the reference population, the nation as a whole. Deviation from the optimum ratio in the states is interpreted as a manifestation of inequitable resource distribution. The results show striking differences in needs and resources. Resource/need ratio varied from 0.21 in Oaxaca to 3.79 in Distrito Federal. The states least favoured in resource sharing were Oaxaca, Puebla, Hidalgo and México. On the other hand, Tamaulipas, Baja California Sur, Quintana Roo and Distrito Federal exceeded the optimum. These indexes permit a quantitative expression of the relationship between need and resources in order to reach geographical equity.

The article reviews the meaning of the terms health and illness, and seeks to define those aspects of these concepts that are most related to the supply of health services. After considering the process of health and illness and its implications for the the planning of health care, the authors express the need for conceptual models of health and environment (physical and social) that can be related to the objectives of the health system. As a part of the search for a better population data base, certain health and welfare indicators are suggested. The discussion concludes with a brief strategy for the operationalization of the health/illness continuum as a part of the planning for a national health service.

The differential in mortality by sex has not been broadly studied in Mexico. In this work mortality by sex in under one year old children and infants by federal entity for the main infectious diseases during 1980-1982 was analyzed. The results showed that the rate of mortality by sex (RMS) for under one year old children was higher than one, which means that there is a male over-mortality for that group of age. In the one to four year old children group, there were three entities that showed over-mortality among women. The analysis of the proportional mortality revealed that 40 to 50 percent of deaths in under one year old children were due to gastroenteral and respiratory infections. The probable causes of the male over-mortality observed and the need to determine the regional patterns of mortality are also discussed.