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Biomedical subjects

C G Victora

Publications and source records attributed to C G Victora.

At least 37 records · Page 2Linked to original sources

The epidemiological transition in maternal and child health in a Brazilian city, 1982-93: a comparison of two population-based cohorts.

Two studies carried out in 1982 and 1993 in the city of Pelotas, Southern Brazil, provide a unique opportunity for assessing the impact on maternal and child health of the economic and health care changes, which took place in Brazil in this period. The cohorts of mothers and infants of 1982 and 1993 were studied from the time of delivery. In both years, all mothers identified in the city's maternity hospitals answered a standardised questionnaire and their infants were examined. Over 99% of all children born in the city in each of the 2 years were included in the cohorts. Deaths occurring among these children were monitored prospectively, as well as all hospital admissions in the 1993 cohort. In the 1982 study, attempts were made to locate a 25% sample of the children at the mean age of 12 months using the addresses collected at the hospital (82% of the children were located), and all of the cohort children at the mean age of 20 months and 42 months, through a city census (87% were located in both follow-ups). In the 1993 study, 20% of all children plus all low birthweight infants were sought at 12 months of age, using the addresses collected at the hospital, and 95% were successfully traced. There was a 12% fall in the number of births occurring in 1993 (5,304 births), in comparison with 1982 (6,011 births), in spite of the increase in the population of reproductive age in the city during the decade. There was a marked difference in maternal height and weight at the beginning of pregnancy, with women giving birth in 1993 being, on average, 3.4 cm taller and 2.5 kg heavier than those who gave birth in 1982. The proportion of preterm babies (<37 weeks), measured by the date of last menstrual period, increased from 5.6% in 1982 to 7.5% in 1993. The median duration of breast feeding increased from 3.1 months in 1982 to 4.0 months in 1993. At 12 months of age, the prevalence of deficit of weight for age decreased from 5.4% in 1982 to 3.7% in 1993. The prevalence of deficit of height for age, however, increased from 5.3% to 6.1%. The perinatal mortality rate dropped 31%, from 32.2 per 1,000 births in 1982 to 22.1 deaths per 1,000 births in 1993. There was also a marked reduction in the infant mortality rate, from 36.4 per 1,000 livebirths in 1982 to 21.1 per 1,000 livebirths in 1993. The findings of the study indicate that there were improvements in the decade for most of the indicators evaluated, with the exception of birthweight and gestational age. It appears that improvements in perinatal and infant mortality rates are largely due to improvements in the health care sector.

Adult↗

Ethnicity and infant health in Southern Brazil. A birth cohort study.

BACKGROUND: Black children present more health problems than white children, but little information is available from less developed countries. Ethnic inequalities may vary according to country, and studies from developing countries are needed to evaluate possible differentials and their magnitude, and identify social and health interventions. METHODS: Birth cohort study in Pelotas, Southern Brazil. Information collected during the perinatal period in hospitals, and at home at 1, 3, 6 and 12 months of age. In all, 5305 children were studied at birth, 96.8% of the sample of 1461 at 6 months, and 93.4% of this sample at 12 months of age. RESULTS: Of the children, 28% were African Brazilian. Socioeconomic position was lower among families of black children, and mothers presented a number of unfavourable characteristics. Black children presented higher prevalences of low birthweight (LBW), preterm and small-for-gestational age (SGA), were less often immunized, had more deficits of weight-for-age and height-for-age, and higher early neonatal and infant mortality. When a number of covariates, including antenatal care, were added to a multiple regression analysis the odds ratios were markedly reduced, but there was still a clear trend towards worse results for black children. Black mothers had some aspects of antenatal care of lower quality and were submitted less frequently to caesarean sections and episiotomies. CONCLUSIONS: Black infants experienced a much worse health status than white infants. Socioeconomic and other variables played a major role in determining inequalities between these ethnic groups. Antenatal care was especially important in explaining differentials in risk between black and white children.

Africa↗

Short-term benefits of catch-up growth for small-for-gestational-age infants.

BACKGROUND: Recent studies suggest that small newborns who present rapid postnatal growth may have an increased risk of chronic diseases in adulthood. On the other hand, it is widely assumed that catch-up growth is desirable for low birthweight children, but the literature on this subject is limited. METHODS: Population-based cohort study in southern Brazil, with 3582 children examined at birth, 20 and 42 months of age. Catch-up growth from 0 to 20 months was related to subsequent risks of hospital admissions and mortality. RESULTS: Children who were small-for-gestational-age (SGA) but presented substantial weight gain (> or =0.66 z-score) up to the age of 20 months had 65% fewer subsequent hospital admissions than other SGA children (5.6% versus 16.0%; P < 0.001). Mortality to age 5 years was 75% lower (3 versus 13 per 1000, a non-significant difference based on a small number of deaths) for rapid-growing SGA children compared to the remaining SGA children. Their admission and mortality rates were similar to those observed for children born with an appropriate birthweight for their gestational age (AGA). Similar positive effects of rapid growth were found for AGA children. CONCLUSION: There appear to be definite benefits associated with catch-up growth. Growth promotion efforts for infants who are born small should take into account their possible short- and long-term consequences.

Analysis of Variance↗

Breast-feeding has a limited long-term effect on anthropometry and body composition of Brazilian mothers.

The effect of lactation on maternal nutrition is controversial. Some studies have shown that breast-feeding reduces maternal weight, whereas some have not. All studies have been restricted to the first 2 y after delivery. We investigated the effect of lactation on maternal nutrition 5 y after delivery. All mothers giving birth in the city of Pelotas, Brazil, in 1993 were interviewed and weighed soon after delivery; information was also obtained on prepregnancy weight. In 1994, information on breast-feeding duration and pattern was collected for a 20% subsample. They were seen again in 1998, and those eligible (nonsmokers, no subsequent pregnancy, last birth weight > or = 2500 g) underwent measurements for weight, height, waist, hip and arm circumferences, triceps and subscapular skinfolds. The following indices were calculated in 312 women: body mass index, waist/hip ratio, arm fat area, the percentage of body fat assessed through skinfolds, and weight and body mass index change since before conception. The percentage of body fat was also measured through bioimpedance for half of the sample. After adjustment for confounding, all outcomes generally showed a similar pattern, i.e., mothers who breast-fed for 6-11.9 mo had lower measurements than those with shorter or longer durations. However, only the association with bioimpedance was significant (P < 0.03), and that for arm fat area tended to be significant (P = 0.06). Exclusive or predominant breastfeeding at 4 mo was associated with lower waist circumference (P = 0.05) and the percentage of body fat measured through skinfolds (P = 0.04). This study suggests that the relationship between breast-feeding and long-term changes in maternal weight is complex and, in this population, not particularly strong.

Adipose Tissue↗

Nutrition counseling increases weight gain among Brazilian children.

To assess the impact on child growth of the nutrition-counseling component of the Integrated Management of Childhood Illnesses (IMCI) strategy, a randomized trial was implemented. All 28 government health centers in a Southern Brazil city were paired according to baseline nutritional indicators. One center from each pair was randomly selected and its doctors received 20-h training in nutrition counseling. Thirty-three doctors were included and 12-13 patients < 18 mo of age from each doctor were recruited. The study included testing the knowledge of doctors, observing consultations and visiting the children at home 8, 45 and 180 d after the initial consultation. Maternal knowledge, practices and adherence to nutritional recommendations were assessed, and anthropometric measurements were taken. Day-long dietary intake was evaluated on a subsample of children. Doctors in the intervention group had better knowledge of child nutrition and improved assessment and counseling practices. Maternal recall of recommendations was higher in the intervention than in the control group, as was satisfaction with the consultation. Reported use of recommended foods was also increased. Daily fat intake was higher in the intervention than in the control group; mean daily intakes of energy and zinc also tended to improve. Children 12 mo of age or older had improved weight gain and a positive but nonsignificant improvement in length. Nutrition-counseling training improved doctors' performances, maternal practices and the diets and weight gain of children. The randomized design with blind outcome evaluation strongly supports a causal link. These results should be replicated in other settings.

Brazil↗

The low prevalence of weight-for-height deficits in Brazilian children is related to body proportions.

Compared with children from other regions, Latin American children living in poverty have much lower prevalences of weight-for-height deficits than would be expected given the observed rates of stunting. This study was aimed at investigating whether variations in body proportions, particularly abdominal circumference, could explain this paradoxical finding. In a cross-sectional study, children aged 12-35 mo (n = 197) were studied in Southern Brazil. Half of these children were from a high socioeconomic status (SES) group whose growth closely resembled that of the National Center for Health Statistics (NCHS)/WHO reference; the other half were from low income families. The following 11 anthropometric measurements were collected: weight, height, sitting height/crown-rump length, head, chest, upper arm and abdominal circumference, triceps, biceps, subscapular and suprailiac skinfolds. These measures were compared between the two groups of children and with values for North American children [mostly from Second National Health and Nutrition Examination Survey (NHANES II)]. For nearly all measures, low SES Brazilian children tended to be smaller than both high SES and North American children. However, when body proportionality was assessed by dividing the measurements by the child's height, these differences tended to disappear or even to change direction, as was the case for head, chest and abdominal circumferences. Mean abdominal circumference was virtually identical between low and high SES children, and the former had larger abdomens for a given height. Despite slight differences in measuring techniques, Brazilian children had larger abdomens than North Americans. These findings may explain in part why deprived Latin American children have higher weights for their height compared with the NCHS/WHO reference.

Abdomen↗

Worldwide timing of growth faltering: implications for nutritional interventions.

OBJECTIVE: It is widely assumed that growth faltering starts at around 3 months of age, but there has been no systematic assessment of its timing using representative national datasets from a variety of countries. METHODOLOGY: The World Health Organization Global Database on Child Growth and Malnutrition includes the results of 39 nationally representative datasets from recent surveys in developing countries. Based on these data, mean z scores of weight for age, length/height for age, and weight for length/height were compared with the National Center for Health Statistics and Cambridge growth references, for children younger than 60 months. RESULTS: Mean weights start to falter at about 3 months of age and decline rapidly until about 12 months, with a markedly slower decline until about 18 to 19 months and a catch-up pattern after that. Growth faltering in weight for length/height is restricted to the first 15 months of life, followed by rapid improvement. For length/height for age, the global mean is surprisingly close to National Center for Health Statistics and Cambridge references at birth, but faltering starts immediately afterward, lasting well into the third year. CONCLUSIONS: These findings highlight the need for prenatal and early life interventions to prevent growth failure.

Anthropometry↗

[Smoking time evolution among medical students, 1986, 1991, 1996].

OBJECTIVE: To evaluate trends in smoking habits among medical students in the last ten years. METHODS: In 1996, a cross-sectional survey of smoking habits was carried out among students in the first to the fifth year of medical school. Four hundred and nine students answered the questionnaire. A regular smoker was defined as someone who smokes one or more cigarettes a day at least for one month; former smokers were the ones who used to smoke in the past but not at the moment. Similar research was conducted in 1986 and 1991. RESULTS/CONCLUSIONS: Smoking prevalence was 11% compared with 14% in 1991 and 21% in 1986. Although there was a significant reduction of smoking in the last three years, the actual decrease from 1991 to 1996 was less than that observed from 1986 to 1991. In 1961, the prevalence of smoking increased in the last years of medical school. There were no significant differences regarding gender. Most of the students were in favor of not allowing smoking in both the school areas and hospital wards. They also mentioned in their questionnaire that smoking was poorly approached during medical school.

Adult↗

Influence of mate drinking, hot beverages and diet on esophageal cancer risk in South America.

To estimate the effects of consuming hot beverages, including mate (an infusion of the herb Ilex paraguayensis), tea, coffee and coffee with milk, and other food items on esophageal cancer risk, we analyzed data from 830 cases and 1,779 controls participating in a series of 5 hospital-based case-control studies of squamous-cell carcinoma of the esophagus conducted in high-risk areas of South America. After adjusting for the strong effects of tobacco and alcohol consumption, both heavy mate drinking (>1 l/day) and self-reported very hot mate drinking were significantly associated with esophageal cancer risk in men and women. The magnitude and strength of the association for mate amount and, to a lesser extent, mate temperature were higher for women than men. The joint effects of mate amount and mate temperature were more than multiplicative, following a statistically significant synergistic interaction (p = 0.02) which was particularly evident among heavy drinkers (>1.50 l/day) of very hot mate (odds ratio = 4.14, 95% confidence interval: 2.24-7.67) compared to light drinkers (<0.50 l/day) of cold/warm/hot mate. Consumption of other very hot beverages, such as tea and coffee with milk but not coffee alone, was also significantly associated with an increased risk, in the 2- to 4-fold range. Statistically significant protective associations were identified for high consumption of vegetables, fruits, cereals and tea. In contrast, frequent consumption of meat, animal fats and salt was associated with a moderately increased risk. This pooled analysis adds evidence for a carcinogenic effect of chronic thermal injury in the esophagus induced by the consumption of very hot drinks, including mate. Our study further confirms the protective effect of a dietary pattern characterized by daily consumption of fruits and vegetables and low consumption of meat and animal fats.

Aged↗

Explaining trends in inequities: evidence from Brazilian child health studies.

There is considerable international concern that child-health inequities seem to be getting worse between and within richer and poorer countries. The "inverse equity hypothesis" is proposed to explain how such health inequities may get worse, remain the same, or improve over time. We postulate that as new public-health interventions and programmes initially reach those of higher socioeconomic status and only later affect the poor, there are early increases in inequity ratios for coverage, morbidity, and mortality indicators. Inequities only improve later when the rich have achieved new minimum achievable levels for morbidity and mortality and the poor gain greater access to the interventions. The hypothesis was examined using three epidemiological data sets for time trends in child-health inequities within Brazil. Time trends for inequity ratios for morbidity and mortality, which were consistent with the hypothesis, showed both improvements and deterioration over time, despite the indicators showing absolute improvements in health status between rich and poor.

Brazil↗

Smoking and drinking cessation and risk of esophageal cancer (Spain).

OBJECTIVES: To explore the effectiveness of alcohol drinking and tobacco smoking cessation in reducing esophageal cancer risk, taking into account the key characteristics of each habit and the simultaneous exposure to both habits. METHODS: Data from a series of five hospital-based case-control studies of incident squamous-cell carcinoma of the esophagus conducted by the International Agency for Research on Cancer (IARC, Lyon, France) in high-risk areas in South America were combined and analyzed by multivariate logistic regression procedures. A total of 2063 men (655 case patients and 1408 control subjects) were included in the pooled analysis. RESULTS: For either habit, the risk of esophageal cancer decreased rapidly, strongly and significantly with longer periods of abstention. The risk reduction was statistically significant regardless of the intensity and duration of each habit and the type of tobacco or alcoholic drink consumed. For subjects exposed to both risk factors, the protective effect of quitting both habits appeared to be synergistic, reaching, after only five to nine years of simultaneous cessation of both exposures, a 70% risk reduction, a reduction that clearly overlapped with the risk intervals of both never-smokers and never-drinkers. The risk benefit of merely quitting alcohol drinking was delayed (>10 years of cessation) unless it was also accompanied by a few years of smoking cessation. CONCLUSIONS: Our findings solidly demonstrate for the first time the effectiveness of smoking and drinking cessation in reducing esophageal cancer risk. For the large proportion of subjects in the general population exposed to both risk factors, our results further emphasize the importance of smoking cessation to effectively reduce cancer risk.

Alcohol Drinking↗

[Prevalence and risk factors for anemia in Southern Brazil].

OBJECTIVE: To measure the prevalence and evaluate the risk factors of anemia. METHODS: Cross sectional populational based study of the urban area of Criciuma town, in the state of Santa Catarina, Southern Brazil. The study population was a probabilistic sample of 476 children aged under three years. RESULTS: The prevalence of anemia found in the sample was 60.4% for children aged 0 to 35.9 months according to the Brault-Dubuc criteria and 54% for children aged 6 to 35.9 months according to the OMS criteria. The prevalence of anemia increases with age up to 18 months-old and then decreases. It is less prevalent in families where the father has a higher education level and where there is a higher total family income. Nevertheless, even within the 25% higher income group 40% of the children are anemic. The prevalence of anemia is higher among children living in unfinished and overcrowded houses, where the toilet is not equipped with flush, and among children who have two or more older brothers. It is also higher among teenager mothers (<20 years), and 35 years old or older mothers. The prevalence of anemia is lower among women who had 5 to 9 prenatal visits during pregnancy. Low weight at birth was associated with iron deficiency. The nutritional condition was associated with anemia only according to weight/age criteria. Hospitalizations in the last 12 months were not associated with the disease. In the hierarchical multivariate analysis children age, family income, and crowded house were the only significant variables. Reproductive health history, health service visits, birth weight, breast-feeding, anthropometry, and morbidity did not characterize a risk factor of anemia in the multivariate analysis. CONCLUSIONS: The study makes it evident that social inequality is a strong determinant of anemia. The risk imposed by anemia to children in regard to their health and intellectual development requires immediate action.

Age Factors↗

[Asthmatic children's risk factors for emergency room visits, Brazil].

OBJECTIVES: To study a sample of asthmatic children to get to know how the disease is managed by caretakers and to identify predictive factors associated with attendance in emergency room for asthma. METHODS: A cross-sectional study nested in a cohort was undertaken in the urban area of Pelotas, Southern Brazil. 981 children aged 4-5 years, who belong to the cohort of 1993, participated in this study. RESULTS: The asthma prevalence in the children sample was 25.4%. Morbidity for asthma was quite high: 31% of the children were seen in emergency rooms in the last year, 57% attended medical clinics and 26% were hospitalized in the first 4 years of life. The crude analysis identified the following predictive factors for emergency room visits: low educational level (RO=4.1), low family income (RO=6. 5), 3 or more children sleeping in the same room (RO=2.2), severity of asthma attacks (RO=2.7), use of asthma medicines in the last year (RO=1.9) and hospitalizations due to asthma (RO=3.0). Multivariate analyses using logistic regression were used to adjust each variable for the effect of the remainder. CONCLUSIONS: The asthma prevalence among preschool children in Pelotas is high, resulting therefore in high morbidity. The predictor factors for emergency room visits due to asthma found, after multivariate analysis, were mother's low educational level, severity of the asthma attacks and hospitalization.

Asthma↗

[Diagnosis of overweight in adolescents: comparative study of the performance different criteria for body mass index].

OBJECTIVE: In an attempt to simplify the screening process for detecting obesity in adolescence, the performance of different cutoff values for body mass index (BMI) was assessed in a population-based cohort in Southern Brazil. METHODS: A total of 493 adolescents aged 15-16 years who lived in the city of Pelotas, Brazil, were studied. Obesity was defined according to the WHO criteria taking into account age and sex (a BMI equal to or greater than the 85th percentile of the NHANES I reference, plus subscapular and triceps skinfold equal to or greater than the 90th percentile of the same reference). Different BMI cutoff values were used to assess their specificity and sensitivity. RESULTS: For boys, BMI>/=25 kg/m(2) showed the best performance for detecting obesity, with a sensitivity of 90% and only 5% of false positives. The Brazilian proposed criteria that was used had 100% sensitivity but up to 23% of false positives. Higher cutoff values were also tested, but there was a slight increase in specificity, accompanied by a marked reduction in sensitivity. CONCLUSIONS: The BMI cutoff of 25 kg/m(2) presented the best performance for screening obesity in the studied sample, and it is recommended for adolescents aged 15 and more in populations with similar characteristics. It provides a single cutoff value to be used in primary health services, eliminating the need for age and sex-specific values and skinfold measurements, and it is also consistent with the cutoff value proposed to identifying overweight adults.

Adolescent↗

[Maternal nutrition and duration of breastfeeding in a birth cohort in Pelotas, Brazil].

OBJECTIVE: The effects of maternal nutritional status on the duration of breastfeeding are inconsistent in the literature. A population-based cohort study was set to investigate this relationship. METHODS: Nine hundred and seventy seven mothers giving birth in 1993 (20% of that year's births) were studied. Studied maternal characteristics included nutritional status, social, economic, and demographic variables. The effects of these variables on the prevalence of breastfeeding at six months were analyzed through logistic regression. Cox regression was applied to analyze the effects on the duration of breastfeeding. RESULTS: Multivariate logistic regression analysis showed a higher prevalence of breastfeeding among women with a pre-pregnancy weight of 49 kg or more (odds ratio = 1.31; CI(95%) 1.04 - 1.64). The association with maternal height was not significant (p=0.06). Cox regression also showed a non-significant protective effect of having a higher pre-pregnancy weight (hazard ratio = 0.91; CI(95%) 0.82 - 1.01). The duration of breastfeeding duration was not associated with maternal height. Weight gain during pregnancy was not associated with breastfeeding in either analyses. Other variables associated with the duration of breastfeeding in both analyses were maternal age, parity, smoking, and gestational age. Family income was associated with the prevalence of breastfeeding at six months, and birthweight was associated with the duration of breastfeeding. CONCLUSIONS: Pre-pregnancy nutritional status is a stronger predictor of breastfeeding than weight gain during pregnancy.

Adolescent↗

Reducing deaths from diarrhoea through oral rehydration therapy.

In 1980, diarrhoea was the leading cause of child mortality, accounting for 4.6 million deaths annually. Efforts to control diarrhoea over the past decade have been based on multiple, potentially powerful interventions implemented more or less simultaneously. Oral rehydration therapy (ORT) was introduced in 1979 and rapidly became the cornerstone of programmes for the control of diarrhoeal diseases. We report on the strategy for controlling diarrhoea through case management, with special reference to ORT, and on the relationship between its implementation and reduced mortality. Population-based data on the coverage and quality of facility-based use of ORT are scarce, despite its potential importance in reducing mortality, especially for severe cases. ORT use rates during the 1980s are available for only a few countries. An improvement in the availability of data occurred in the mid-1990s. The study of time trends is hampered by the use of several different definitions of ORT. Nevertheless, the data show positive trends in diarrhoea management in most parts of the world. ORT is now given to the majority of children with diarrhoea. The annual number of deaths attributable to diarrhoea among children aged under 5 years fell from the estimated 4.6 million in 1980 to about 1.5 million today. Case studies in Brazil, Egypt, Mexico, and the Philippines confirm increases in the use of ORT which are concomitant with marked falls in mortality. In some countries, possible alternative explanations for the observed decline in mortality have been fairly confidently ruled out. Experience with ORT can provide useful guidance for child survival programmes. With adequate political will and financial support, cost-effective interventions other than that of immunization can be successfully delivered by national programmes. Furthermore, there are important lessons for evaluators. The population-based data needed to establish trends in health service delivery, outcomes and impact are not available in respect of diarrhoea, as is true for malaria, pneumonia and other major childhood conditions. Standard indicators and measurement methods should be established. Efforts to change existing global indicators should be firmly resisted. Support should be given for the continuing evaluation and documentation activities needed to guide future public health policies and programmes.

Child, Preschool↗

Independent and joint effects of tobacco smoking and alcohol drinking on the risk of esophageal cancer in men and women.

To estimate the independent and joint effects of tobacco smoking and alcohol drinking, we analyzed data from a series of 5 hospital-based case-control studies of squamous-cell carcinoma of the esophagus conducted in high-risk areas in South America. A total of 830 case subjects and 1779 control subjects were included in the pooled analysis. All exposure characteristics of amount, duration, cessation and type of alcohol and tobacco consumed were strongly related to esophageal-cancer risk in both sexes. Women had the same exposure profile as men, but the magnitudes of the associations were lower than were those among men. Black-tobacco smoking was associated with a 2-fold increased risk as compared with the smoking of blond or mixed tobacco. Quitting either of the 2 habits significantly reduced esophageal-cancer risk. Alcohol and tobacco alone were strongly related to the risk of esophageal cancer, even in the absence of the other exposure. A history of simultaneous exposure to cigarette smoking and alcohol drinking had a strong multiplicative effect on risk. Concomitant exposure to heavy alcohol drinking and black-tobacco smoking identified the group with the highest risk for developing esophageal cancer (odds ratio = 107). A synergistic interaction was found between the 2 habits, particularly in women and in moderately exposed men. Moderate cigarette smoking without drinking and moderate alcohol drinking without smoking had a negligible effect on esophageal-cancer risk. However, simultaneous exposure to the same moderate amounts increased the risk 12- to 19-fold in men and in women respectively. The overall public-health implications of these findings are obvious for a tumor that depends on preventive strategies for its control.

Adult↗