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B R Kirkwood

Publications and source records attributed to B R Kirkwood.

At least 19 recordsLinked to original sources
PubMed1999

Potential interventions for the prevention of childhood pneumonia in developing countries: improving nutrition.

Acute respiratory infections are the leading cause of childhood death in developing countries. Current efforts at mortality control focus on case management and immunization, but other preventive strategies may have a broader and more sustainable effect. This review, commissioned by the World Health Organization, examines the relations between pneumonia and nutritional factors and estimates the potential effect of nutritional interventions. Low birth weight, malnutrition (as assessed through anthropometry), and lack of breast-feeding appear to be important risk factors for childhood pneumonia, and nutritional interventions may have a sizeable effect in reducing deaths from pneumonia. For all regions except Latin America, interventions to prevent malnutrition and low birth weight look more promising than does breast-feeding promotion. In Latin America, breast-feeding promotion would have an effect similar to that of improving birth weights, whereas interventions to prevent malnutrition are likely to have less of an effect. These findings emphasize the need for tailoring interventions to specific national and even local conditions.

Breast Feeding↗
PubMed1998

The impact of vitamin A supplementation given during a pneumonia episode on the subsequent morbidity of children.

OBJECTIVE: To evaluate the impact of large-dose vitamin A supplementation given to infants > 6 months old (200000 IU) and to preschool children aged 1-4 years (400000 IU) during a pneumonia episode, on their subsequent morbidity and severe morbidity. METHOD: In a randomized, double-blind, placebo controlled trial, the children were followed-up with 2-weekly visits at home for 16 weeks, with the first visit 2 weeks after treatment for pneumonia was initiated. The field workers asked about the presence of morbidity on the day of the visit and in the previous two weeks and about the occurrence and number of clinic attendances and hospital admissions since the last visit. They also measured the patients respiratory rate and temperature and assessed the children for the presence of cyanosis, chest indrawing and wheezing. RESULTS: Except for the prevalence of diet refusal which was higher in the vitamin A group, no differences between the study groups were observed, either in the prevalence of morbidity or in the incidence of clinic attendances and hospital admissions. CONCLUSION: No evidence was found for a beneficial effect of vitamin A given during acute pneumonia on the subsequent morbidity and severe morbidity of children in a population with marginal vitamin A deficiency.

Brazil↗
PubMed1997

Randomised, double blind, placebo controlled clinical trial of efficacy of vitamin A treatment in non-measles childhood pneumonia.

OBJECTIVE: To evaluate the impact on clinical recovery and severity of the addition of large doses of vitamin A to the standard treatment for childhood pneumonia. DESIGN: A randomised, double blind, placebo controlled trial. SETTING: Study children were recruited at a public hospital in Recife, north east Brazil, an area of marginal vitamin A deficiency. SUBJECTS: 472 children aged 6 to 59 months with clinical diagnosis of pneumonia. INTERVENTIONS: 200,000 IU (infants) or 400,000 IU (1-4 year olds) of vitamin A in oil or similar capsules of placebo divided into two daily oral doses, in addition to the standard treatment. MAIN OUTCOME MEASURES: Duration of the episode and incidence of adverse outcomes. RESULTS: The groups were similar with respect to overall duration of pneumonia and incidence of adverse outcomes. Children who received vitamin A, however, were less likely to have fever by day 3 (P = 0.008) and were 29% less likely to fail to respond to the first line antibiotic (P = 0.054). CONCLUSION: There was little evidence for an effect of vitamin A treatment on the immediate outcome of the pneumonia episode.

Child, Preschool↗
PubMed1997

Issues in the design and interpretation of studies to evaluate the impact of community-based interventions.

Increasingly, epidemiologists are faced with the need to evaluate the impact of an intervention that is delivered at the level of a community or cluster of individuals, rather than at the individual level. This has profound implications for the design and interpretation of a study to evaluate its impact. We start by discussing the issues arising in the extension of the randomized double-blind controlled trial methodology to the evaluation of interventions delivered to clusters of individuals, or to whole communities, where the unit of randomization is a cluster of individuals rather than an individual. We then consider alternative approaches to design, discuss their relative strengths and weaknesses and present a framework of design options. Finally we propose a pragmatic approach to evaluation design in this setting. We believe that the answer lies in the judicious selection of different design elements, combined in such a way that when the evidence from each is presented together, a clear picture of the impact of the intervention emerges. We illustrate this using an example from the recent literature.

Community Medicine↗
PubMed1997

Low body weight: a simple indicator of the risk of dehydration among children with diarrhoea.

The early identification of children at high risk of dehydration as a consequence of diarrhoea would be of great value for health care workers in developing countries. By comparing children aged less than two years with diarrhoea and moderate to severe dehydration with matched controls who had uncomplicated diarrhoea, a number of prognostic factors were assessed. Low body weight, regardless of age, was strongly associated with the risk of dehydration; using 7.0 kg as a cut-off, it had a sensitivity of 75% and a specificity of 68%. Low body weight was superior to more complex anthropometric indices, including weight for age, weight for length or length for age, and also to early signs and symptoms during the episode. By reflecting the effects of both young age and those of malnutrition, low body weight may prove to be a simple indicator for predicting dehydration among children with diarrhoea presenting at a health service.

Body Weight↗
PubMed1996

Is prevalence of diarrhea a better predictor of subsequent mortality and weight gain than diarrhea incidence?

A number of different outcome measures have been proposed for use in prospective studies of morbidity associated with childhood diarrhea. These include the number of episodes experienced by each child over a defined period (a measure of incidence) and the number of days of diarrhea divided by the total number of days of observation for each child (a measure denoted "longitudinal prevalence"). The authors examined data from Ghana to determine which of these measures is more strongly associated with weight gain over a 4-month period and subsequent mortality. Both diarrhea incidence and longitudinal prevalence were associated with weight gain in children aged 6-23 months, but a statistically stronger association was observed with longitudinal prevalence (likelihood ratio statistic 28.95 on 1 degree of freedom against 19.70 for incidence). Neither measure was associated with weight gain in younger or older children. Longitudinal prevalence, but not incidence, was strongly associated with subsequent mortality (p = 0.002 for longitudinal prevalence; p = 0.557 for incidence). Although many epidemiologic studies of diarrhea focus on incidence, these data suggest that longitudinal prevalence is more strongly predictive of long-term health outcome. The authors conclude that longitudinal prevalence merits greater attention as a measure of outcome in diarrhea studies.

Child, Preschool↗
PubMed1996

Effect of vitamin A supplementation on the growth of young children in northern Ghana.

The effect of prophylactic vitamin A supplementation on child growth was studies in two randomized, placebo-controlled trials carried out in adjacent areas of northern Ghana between 1989 and 1991. In the Health Study, the midupper arm circumference (MUAC) and weight of the approximately 1500 children (aged 6-59 mo) in the trial were measured every 4 wk for up to 52 wk. In addition, MUAC, weight, and height were measured at each of the four potential vitamin A or placebo dosing times, which were at 4-mo intervals. In the Survival Study, MUAC and weight were measured at 4-mo intervals at each of seven dosing rounds in the approximately 15 000 children currently in the trial. Overall, there were > 90 000 observations of weight and MUAC in > 25 000 children, and 3347 observations of length/height in 1546 children. Within each study, the mean monthly weight, MUAC, and gains in length/height in each treatment group were compared by using multilevel modeling. There were no significant differences in either MUAC or gains in length/height. The only significant difference in weight gain was in the Survival Study: children in the vitamin A-supplemented group who were > or = 36 mo of age had a mean weight gain that was 3 g lower per month (95% CI: 0.4, 5.0, P = 0.02) than that in the placebo group; a difference that was unlikely to be functionally important in this age group. Vitamin A supplementation did not lead to any increased growth in this population of young children, in whom supplementation reduced mortality and severe morbidity substantially.

Anthropometry↗
PubMed1996

Risk factors for childhood pneumonia among the urban poor in Fortaleza, Brazil: a case--control study.

Reported are the results of a case-control study carried out between July 1989 and June 1990 in Fortaleza city, Ceará State, Brazil, to determine the factors that place young children living in urban slum conditions at increased risk of contracting pneumonia. Cases were 650 under-2-year-olds with a radiological diagnosis of pneumonia who were recruited at the main paediatric hospital in the city over a full calendar year. Age-matched controls were recruited from the neighbourhood where the cases lived. Cases and controls were compared with respect to a variety of sociodemographic, environmental, reproductive, nutritional, and morbidity factors, and a risk factor questionnaire was administered to the mother of each child or to the child's normal guardian. Cases and controls were also weighed and measured. Malnutrition was the most important risk factor for childhood pneumonia in the study population, with weight-for-age, height-for-age, and weight-for-height also being important risk factors. In view of the high prevalence of stunting in the study population, there is an urgent need to reduce the level of malnutrition as a priority. Attendance at a day care centre was also associated with a high odds ratio. In view of the growing numbers of children attending day care centres in both developing and developed countries, it is essential that ways be identified to improve the design and management of such centres in order to minimize the risk of pneumonia. Increased risks of childhood pneumonia were also associated with low birth weight, non-breast-feeding, crowding, high parity, and incomplete vaccination status, but not with socioeconomic status or environmental variables. Finally, children who had suffered from previous episodes of wheezing or been hospitalized for pneumonia had a greater than threefold increased risk of contracting the disease.

Adult↗
PubMed1995

Vitamin A supplementation and childhood malaria in northern Ghana.

Two companion, randomized, placebo-controlled trials of prophylactic vitamin A supplementation provided the opportunity to assess the impact of supplementation on malaria parasitemia, morbidity, and mortality in young children in northern Ghana. In the mortality study, 21,906 children were visited every 4 mo over 2 y, and in the morbidity study 1455 children were visited weekly for 1 y. There was no difference between children supplemented with vitamin A and those given placebo in malaria mortality rates (rate ratio = 1.03; 95% CI 0.74, 1.43) or fever incidence based on reported symptoms. Malaria parasitemia rates, parasite densities in children with a positive blood smear, and rates of probable malaria illness also did not differ between treatment groups. There was no correlation between serum retinol at the beginning of the trial and subsequent malaria parasitemia in children who received placebo (r = 0.01). It is concluded that vitamin A supplementation had no impact on malaria in this population.

Child↗
PubMed1995

Vitamin A supplementation, morbidity, and serum acute-phase proteins in young Ghanaian children.

The association of vitamin A supplementation with concentrations of positive acute-phase proteins in the serum was investigated in the Child Health Study of the Ghana Vitamin A Supplementation Trials, a randomized, controlled trial of the effect of vitamin A on morbidity in children aged < 5 y. Mean serum concentrations of alpha 1-acid glycoprotein, serum amyloid A, and C-reactive protein did not differ overall between the vitamin A-supplemented and placebo-treated groups. Treatment groups were then subdivided according to what symptoms children had experienced in the week before blood sampling. Acute-phase-protein responses to fever and cough were not affected by vitamin A supplementation. There was a tendency for vitamin A-supplemented children, but not placebo children, to have elevated acute-phase proteins in association with reported vomiting or severe diarrhea. The failure of unsupplemented children to mount an acute-phase response may have contributed to their increased morbidity from gastrointestinal symptoms.

Acute-Phase Proteins↗
PubMed1995

Child morbidity and mortality following vitamin A supplementation in Ghana: time since dosing, number of doses, and time of year.

OBJECTIVES: The impact of large-dose vitamin A supplementation given at intervals of 4 months on child mortality and morbidity was examined according to the time interval since dosing, number of doses received previously, and time of year. METHODS: Two double-blind, randomized, placebo-controlled trials of large doses of vitamin A administered at intervals of 4 months were conducted in adjacent populations in northern Ghana. RESULTS: While vitamin A supplementation significantly reduced the overall incidence of severe illnesses (especially diarrhea with dehydration), clinic attendances, hospital admissions, and mortality, there was no evidence that the impact of each dose of vitamin A was related to the number of doses the child had received previously. There was no evidence that the effectiveness of the supplement waned over the 3 to 5 months between doses. The impact on mortality did not differ significantly by the month in which the supplement had been given. CONCLUSIONS: In the study population, there was no evidence that an interval between doses of less than 4 months would have had a greater impact on severe morbidity or mortality, and the effectiveness of supplementation did not vary by time of year.

Child↗
PubMed1995

Potential interventions for the prevention of childhood pneumonia in developing countries: a systematic review.

This article describes the background and framework for a systematic review of potential interventions for preventing pneumonia among under-5-year-olds in developing countries. Twenty-eight intervention areas are identified in six groups -- immunization, case management/chemoprophylaxis of high-risk children, improving nutrition, reducing environmental pollution, reducing transmission of pathogens, and improving child care practices. Calculation of the potential impacts is illustrated and the expected outcomes are also described.

Child Welfare↗
PubMed1994

Diarrhoea--defining the episode.

BACKGROUND: There is still no consensus on the appropriate definition of an 'episode' of diarrhoea, even though it has been shown that the choice of definition has a major impact on reported incidence rates. Previous work has focused on the observed distribution of illness episodes in time but has not attempted to determine whether the patterns observed depart from those expected by chance. METHODS: A simple theoretical model of the distribution of illness episodes is developed, based on the concept of a 'trigger event'. The model incorporates elements relating to the duration of symptoms, inter-individual variation in incidence rates and seasonality. Appropriate parameters for the model are derived from two empirical datasets. RESULTS: It is shown that short intervals between one aetiologically distinct period of diarrhoea and the next will frequently occur by chance, especially in circumstances where high incidence rates and within-child clustering of illness prevail. The duration of symptoms will have no effect on the length of intervals between periods of illness, and seasonality is unlikely to have a major impact. Over 10% of all non-initial trigger events might be expected to occur during the course of a pre-existing period of diarrhoea, and would not therefore be identified in a study based on reported symptoms. CONCLUSIONS: The findings of previous studies, suggesting that 2 or 3 days without symptoms will generally mark a new episode of diarrhoea, are endorsed. Modelling the expected distribution of illness in time may help to highlight structural or analytical problems with empirical datasets.

Child↗
PubMed1994

Methodological approaches in a baseline study of diarrhoeal morbidity in weaning-age children in rural Zaire.

A community-based prospective study of diarrhoeal morbidity of weaning-age children in 18 geographically separate village clusters was conducted as the baseline phase of a controlled trial of a hygiene education intervention to reduce diarrhoeal diseases in rural Zaire. For 12 weeks trained interviewers collected information at weekly home visits about the diarrhoeal morbidity of 2082 children aged 3-35 months. Included in the analyses were 1914 children (92%) with 9 or more complete weeks of data. Mothers' reporting of the existence or otherwise of episodes appeared reliable, and more than 70% of children had at least one episode of diarrhoea during the 12-week study period, the mean number of episodes being 1.9 per child. Reporting of the start and termination of diarrhoeal episodes was, however, irregularly distributed among the 7 days between successive home interviews, with 36% of all episodes reported as starting on interview days, and 29% reported as ending the day before an interview: in each case, only 14% would have been expected. After adjusting for these reporting biases, 61% of the episodes lasted 2-4 days, but a number of very long duration were also reported, and the mean duration of the episodes was 4.8 days. Children, had, on average, 9.2 days of diarrhoea during the study period. Contrasts with previous characterizations of reporting error in diarrhoeal studies are noted.

Child, Preschool↗
PubMed1994

Community-based hygiene education to reduce diarrhoeal disease in rural Zaire: impact of the intervention on diarrhoeal morbidity.

BACKGROUND: Diarrhoeal disease is a leading cause of morbidity in young children in rural Zaire. Few diarrhoea prevention programmes have been implemented in Bandundu Province, where available data suggest an annual prevalence rate of 10%. The urgent need to reduce diarrhoeal morbidity in Zaire, together with the potential effectiveness and feasibility of hygiene education as a diarrhoea prevention strategy, led to the development of the present research project. METHODS: A randomized, controlled trial of an education intervention to reduce diarrhoea through improved personal and domestic hygiene behaviours was conducted in 18 geographically separate village clusters (sites) in rural Zaire. For 12 weeks baseline information on the diarrhoeal morbidity of 2082 children aged 3-35 months was collected at weekly home visits, and structured observations of hygiene practices related to diarrhoea were made on a subset of 300 families. Intervention messages addressed disposal of animal faeces from the yard, handwashing after defecation and before meal preparation and eating, and disposal of children's faeces. Three months after the start of the intervention and exactly 1 year after the baseline studies, a second diarrhoeal morbidity study and a second observational study were conducted in order to evaluate the intervention. RESULTS: Children in intervention communities experienced an 11% reduction in the risk of reporting diarrhoea during the peak diarrhoeal season, compared to controls (P < 0.025). The largest differences were seen among children aged 24-35 months, with those from intervention communities reporting significantly fewer episodes, shorter mean durations and hence fewer days of diarrhoea. There was some evidence that greater reductions in diarrhoea occurred in sites where the quality of the intervention, a scored measure of volunteer efficacy and community participation, was highest. CONCLUSIONS: The results of this study suggest that hygiene education may be an effective approach to reduce the incidence and duration of diarrhoeal episodes in rural Zaire. Children aged 2 years appear to benefit the most. A Hawthorne effect of the education may contribute to diarrhoeal reductions.

Child, Preschool↗
PubMed1994

Weaning in southern Brazil: is there a "weanling's dilemma"?

In Pelotas, Brazil, 400 newborns from low income families were followed-up until 26 wk of life to study the relationship between their feeding patterns and growth as modified by access to water and by diarrhea. Effects of access to water were the strongest among non-breastfed infants. In houses without indoor water taps, the weight gain of non-breastfed infants during the first 3 mo was approximately half that of partially or predominantly breastfed infants (P < 0.001). In houses with indoor water taps, non-breastfed infants' growth was similar to or exceeded that of predominantly breastfed infants from 2 mo. Predominantly breastfed infants' growth was similar in houses with and without water taps. Breastfed infants had less weight loss per day of diarrhea than non-breastfed infants during the first 4 mo and less diarrhea through 6 mo of life, particularly in houses without taps, in which diarrhea was most prevalent. The existence of a "weanling's dilemma" was approached by comparing the duration of the detrimental effects of not breastfeeding (i.e., 0-3 mo in this study) with the age at which breast milk alone becomes less than optimal for growth (i.e., at 5 mo). Because these two points did not coincide, we conclude that there is no "weaning's dilemma" in this population.

Brazil↗
PubMed1994

Lack of association between vitamin A status and measures of conjunctival epithelial integrity in young children in northern Ghana.

OBJECTIVE: To investigate the association between vitamin A status and conjunctival epithelial function in young children in rural northern Ghana and to consider whether impaired epithelial function was associated with increased measures of systemic infection in these children. DESIGN: Children were selected from the Ghana Vitamin A Supplementation Trials' Child Health Study, a randomized, double-blind, placebo-controlled trial of the effect of vitamin A supplementation on morbidity. Treatment group and serum retinol concentrations were used as measures of vitamin A status, conjunctival impression cytology and tear IgA concentrations as measures of conjunctival epithelial integrity, and serum immunoglobulin and alpha 1-acid glycoprotein concentrations as indicators of chronic or acute systemic infection. SUBJECTS: Children 13-64 months old. INTERVENTION: 60 mg retinol as retinyl palmitate every 4 months for 1 year. RESULTS: Vitamin A status was not significantly associated with epithelial integrity nor with measures of systemic infection. Impaired conjunctival epithelial integrity was also not associated with increased systemic infection. CONCLUSIONS: There was no evidence for a major role of improved epithelial integrity and function on the biochemical indices of chronic or acute systemic infection after vitamin A supplementation. These data support the observations in the main study that vitamin A supplementation did not improve conjunctival impression cytology nor decrease the prevalence of most morbidity symptoms.

Child Nutritional Physiological Phenomena↗