Browsing by Author "Michel Garenne"

Now showing 1 - 14 of 14
  • Thumbnail Image
    Item
    Age-incidence and prevalence of HIV among intact and circumcised men: an analysis of PHIA surveys in Southern Africa
    (2022-10-05) Michel Garenne
    The study investigates the statistical relationship between male circumcision and HIV prevalence in Africa, in the context of the Voluntary Medical Male Circumcision (VMMC) campaigns in place since 2008. Data from the Population-based HIV Impact Assessment (PHIA) surveys conducted in African countries in 2017-2018 were utilized. Six countries with high HIV prevalence, low traditional circumcision and large VMMC programs were selected: Eswatini, Lesotho, Malawi, Namibia, Zambia, Zimbabwe. The statistical analysis investigated the relative risk (RR) of HIV prevalence by circumcision status (circumcised vs intact) among men age 20-59, and the age-incidence of HIV in the two groups among men age 20-49, defined as the linear-logistic slope of the relationship between prevalence and age. Results show that the standardized RR was not different from 1 at older ages (50-59): RR = 0.923, 95% CI = 0.769-1.108, P = 0.390. Furthermore, the age-incidence was at least as high or higher among the circumcised groups than among the intact groups. The standardized RR was lower than 1 at younger ages, and this could be explained by selection biases. HIV prevalence at age 40-59 (27.3%) was also the same in the four groups of circumcision status (intact, traditional, medical, unknown). Results matched earlier observations made in South Africa that circumcised and intact men had similar levels of HIV infection. The study questions the current strategy of large scale VMMC campaigns to control the HIV epidemic. These campaigns also raise a number of ethical issues
  • Thumbnail Image
    Item
    Age-incidence and prevalence of HIV among intact and circumcised men: an analysis of PHIA surveys in Southern Africa
    (2022-10-05) Michel Garenne
    The study investigates the statistical relationship between male circumcision and HIV prevalence in Africa, in the context of the Voluntary Medical Male Circumcision (VMMC) campaigns in place since 2008. Data from the Population-based HIV Impact Assessment (PHIA) surveys conducted in African countries in 2017-2018 were utilized. Six countries with high HIV prevalence, low traditional circumcision and large VMMC programs were selected: Eswatini, Lesotho, Malawi, Namibia, Zambia, Zimbabwe. The statistical analysis investigated the relative risk (RR) of HIV prevalence by circumcision status (circumcised vs intact) among men age 20-59, and the age-incidence of HIV in the two groups among men age 20-49, defined as the linear-logistic slope of the relationship between prevalence and age. Results show that the standardized RR was not different from 1 at older ages (50-59): RR = 0.923, 95% CI = 0.769-1.108, P = 0.390. Furthermore, the age-incidence was at least as high or higher among the circumcised groups than among the intact groups. The standardized RR was lower than 1 at younger ages, and this could be explained by selection biases. HIV prevalence at age 40-59 (27.3%) was also the same in the four groups of circumcision status (intact, traditional, medical, unknown). Results matched earlier observations made in South Africa that circumcised and intact men had similar levels of HIV infection. The study questions the current strategy of large scale VMMC campaigns to control the HIV epidemic. These campaigns also raise a number of ethical issues.
  • Thumbnail Image
    Item
    Anthropometric criteria for best-identifying children at high risk of mortality: a pooled analysis of twelve cohorts
    (2023-02-03) Tanya Khara; Mark Myatt; Kate Sadler; Paluku Bahwere; James A Berkley; James A Berkley; Robert E Black; Erin Boyd; Michel Garenne; Sheila Isanaka; Natasha Lelijveld; Christine McDonald; Andrew Mertens; Martha Mwangome; Kieran O’Brien; Heather Stobaugh; Sunita Taneja; Keith P West; André Briend
    Objective: To understand which anthropometric diagnostic criteria best discriminate higher from lower risk of death in children and explore programme implications. Design: A multiple cohort individual data meta-analysis of mortality risk (within 6 months of measurement) by anthropometric case definitions. Sensitivity, specificity, informedness and inclusivity in predicting mortality, face validity and compatibility with current standards and practice were assessed and operational consequences were modelled. Setting: Community-based cohort studies in twelve low-income countries between 1977 and 2013 in settings where treatment of wasting was not widespread. Participants: Children aged 6 to 59 months. Results: Of the twelve anthropometric case definitions examined, four (weight-forage Z-score (WAZ) <−2), (mid-upper arm circumference (MUAC) <125 mm), (MUAC < 115 mm or WAZ < −3) and (WAZ < −3) had the highest informedness in predicting mortality. A combined case definition (MUAC < 115 mm or WAZ < −3) was better at predicting deaths associated with weight-for-height Z-score <−3 and concurrent wasting and stunting (WaSt) than the single WAZ < −3 case definition. After the assessment of all criteria, the combined case definition performed best. The simulated workload for programmes admitting based on MUAC < 115 mm or WAZ < −3, when adjusted with a proxy for required intensity and/or duration of treatment, was 1·87 times larger than programmes admitting on MUAC < 115 mm alone. Conclusions: A combined case definition detects nearly all deaths associated with severe anthropometric deficits suggesting that therapeutic feeding programmes may achieve higher impact (prevent mortality and improve coverage) by using it. There remain operational questions to examine further before wide-scale adoption can be recommended.
  • Thumbnail Image
    Item
    Anthropometric deficits and the associated risk of death by age and sex in children aged 6-59 months: A meta-analysis
    (2023-08) Susan Thurstans; Stephanie V. Wrottesley; Bridget Fenn; Tanya Khara; Paluku Bahwere; James A. Berkley; Robert E. Black; Erin Boyd; Michel Garenne; Sheila Isanaka; Natasha Lelijveld; Christine M. McDonald; Andrew Mertens; Martha Mwangome; Kieran S. O'Brien; Heather Stobaugh; Sunita Taneja; Keith P. West; Saul Guerrero; Marko Kerac; André Briend; Mark Myatt
    Risk of death from undernutrition is thought to be higher in younger than in older children, but evidence is mixed. Research also demonstrates sex differences whereby boys have a higher prevalence of undernutrition than girls. This analysis described mortality risk associated with anthropometric deficits (wasting, underweight and stunting) in children 6-59 months by age and sex. We categorised children into younger (6-23 months) and older (24-59 months) age groups. Age and sex variations in near-term (within 6 months) mortality risk, associated with individual anthropometric deficits were assessed in a secondary analysis of multi-country cohort data. A random effects meta-analysis was performed. Data from seven low-or-middle-income-countries collected between 1977 and 2013 were analysed. One thousand twenty deaths were recorded for children with anthropometric deficits. Pooled meta-analysis estimates showed no differences by age in absolute mortality risk for wasting (RR 1.08, p = 0.826 for MUAC < 125 mm; RR 1.35, p = 0.272 for WHZ < -2). For underweight and stunting, absolute risk of death was higher in younger (RR 2.57, p < 0.001) compared with older children (RR 2.83, p < 0.001). For all deficits, there were no differences in mortality risk for girls compared with boys. There were no differences in the risk of mortality between younger and older wasted children, supporting continued inclusion of all children under-five in wasting treatment programmes. The risk of mortality associated with underweight and stunting was higher among younger children, suggesting that prevention programmes might be justified in focusing on younger children where resources are limited. There were no sex differences by age in mortality risk for all deficits.
  • No Thumbnail Available
    Item
    Boys or girls? Sex preferences expressed by women in African and Asian demographic surveys
    (2023-03) Michel Garenne; Nancy Stiegler; Jean-Pierre Bouchard
    In this interview with Jean-Pierre Bouchard, demographers Michel Garenne and Nancy Stiegler explore sex-preferences for girls or boys expressed by women who responded to DHS surveys in twenty-nine African and ten Asian countries. The IPUMS/DHS database was used for statistical analysis, bringing together 140 surveys and 2.5 million women aged 15–49. Overall, two-thirds of women were in favour of a balanced number of girls and boys or were indifferent to the composition of the family. In 20.8% of cases they preferred to have more boys, and in 12.6% of cases they preferred to have more girls. These proportions vary considerably between countries, and were influenced by local culture, religion, level of education, household wealth, and to a smaller extent by urban residence. Sex preferences were also influenced by family composition. These preferences are likely to change rapidly over time. Among the countries analysed, eight expressed preferences for more girls, all located in sub-Saharan Africa, and particularly in southern Africa. These preferences could have many consequences, demographic, social and psychological.
  • Thumbnail Image
    Item
    Changing relationships between HIV prevalence and circumcision in Lesotho
    (2022-04-04) Michel Garenne
    The study investigates the complex relationships between circumcision and HIV prevalence in Lesotho, using Demographic and Health surveys (DHS) conducted in 2004, 2009 and 2014. Before the HIV epidemic, about half of the male adult population was circumcised as part of a traditional custom, and this proportion increased markedly after 2008 with the campaigns of Voluntary Medical Male Circumcision (VMMC), while HIV prevalence stayed at the same level. In 2004, HIV prevalence was higher in circumcised groups than in intact groups (RR=1.49, 95% CI=1.20-1.86). This relationship changed over time, and was inversed in 2014 (RR=0.86; 95% CI=0.70-1.06). The changing relationship seems to be due to an interaction with education, with more educated men being more circumcised and having less HIV over time. A multivariate analysis showed no net effect of circumcision on HIV, after controlling for wealth, education, and indicators of marriage and sexual behaviour. A small net effect of VMMC was found, probably due to condom use. In couple studies, the effect of circumcision and VMMC on HIV was not significant, with similar transmission from female to male and male to female. The study questions the amount of effort and money spent on VMMC in Lesotho.
  • Thumbnail Image
    Item
    Changing relationships between HIV prevalence and circumcision in Lesotho
    (2023-04-04) Michel Garenne
    The study investigates the complex relationships between circumcision and HIV prevalence in Lesotho, using Demographic and Health surveys (DHS) conducted in 2004, 2009 and 2014. Before the HIV epidemic, about half of the male adult population was circumcised as part of a traditional custom, and this proportion increased markedly after 2008 with the campaigns of Voluntary Medical Male Circumcision (VMMC), while HIV prevalence stayed at the same level. In 2004, HIV prevalence was higher in circumcised groups than in intact groups (RR=1.49, 95% CI=1.20-1.86). This relationship changed over time, and was inversed in 2014 (RR=0.86; 95% CI=0.70-1.06). The changing relationship seems to be due to an interaction with education, with more educated men being more circumcised and having less HIV over time. A multivariate analysis showed no net effect of circumcision on HIV, after controlling for wealth, education, and indicators of marriage and sexual behaviour. A small net effect of VMMC was found, probably due to condom use. In couple studies, the effect of circumcision and VMMC on HIV was not significant, with similar transmission from female to male and male to female. The study questions the amount of effort and money spent on VMMC in Lesotho.
  • Thumbnail Image
    Item
    Changing sex differences in undernutrition of African children: findings from Demographic and Health Surveys
    (2021-09-07) Michel Garenne; Susan Thurstans; André Briend; Carmel Dolan; Tanya Khara; Mark Myatt; Andrew Seal; Jonathan C. Wells
    The study investigates sex differences in the prevalence of undernutrition in sub-Saharan Africa. Undernutrition was defined by Z-scores using the CDC-2000 growth charts. Some 128 Demographic and Health Surveys (DHS) were analysed, totalling 700,114 children under-five. The results revealed a higher susceptibility of boys to undernutrition. Male-to-female ratios of prevalence averaged 1.18 for stunting (height-for-age Z-score <−2.0); 1.01 for wasting (weight-for-height Z-score <−2.0); 1.05 for underweight (weight-for-age Z-score <−2.0); and 1.29 for concurrent wasting and stunting (weight-for-height and height-for-age Z-scores <−2.0). Sex ratios of prevalence varied with age for stunting and concurrent wasting and stunting, with higher values for children age 0–23 months and lower values for children age 24–59 months. Sex ratios of prevalence tended to increase with declining level of mortality for stunting, underweight and concurrent wasting and stunting, but remained stable for wasting. Comparisons were made with other anthropometric reference sets (NCHS-1977 and WHO-2006), and the results were found to differ somewhat from those obtained with CDC-2000. Possible rationales for these patterns are discussed.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Prognostic value of different anthropometric indices over different measurement intervals to predict mortality in 6–59-month-old children
    (2023-06) André Briend; Mark Myatt; James A Berkley; Robert E Black; Erin Boyd; Michel Garenne; Natasha Lelijveld; Sheila Isanaka; Christine M McDonald; Martha Mwangwome; Kieran S O’Brien; Catherine Schwinger; Heather Stobaugh; Sunita Taneja; Keith P West; Tanya Khara
    Objective: To compare the prognostic value of mid-upper arm circumference (MUAC), weight-for-height Z-score (WHZ) and weight-for-age Z-score (WAZ) for predicting death over periods of 1, 3 and 6 months follow-up in children. Design: Pooled analysis of twelve prospective studies examining survival after anthropometric assessment. Sensitivity and false-positive ratios to predict death within 1, 3 and 6 months were compared for three individual anthropometric indices and their combinations. Setting: Community-based, prospective studies from twelve countries in Africa and Asia. Participants: Children aged 6–59 months living in the study areas. Results: For all anthropometric indices, the receiver operating characteristic curves were higher for shorter than for longer durations of follow-up. Sensitivity was higher for death with 1-month follow-up compared with 6 months by 49 % (95 % CI (30, 69)) for MUAC < 115 mm (P < 0·001), 48 % (95 % CI (9·4, 87)) for WHZ < -3 (P < 0·01) and 28 % (95 % CI (7·6, 42)) for WAZ < -3 (P < 0·005). This was accompanied by an increase in false positives of only 3 % or less. For all durations of follow-up, WAZ < -3 identified more children who died and were not identified by WHZ < -3 or by MUAC < 115 mm, 120 mm or 125 mm, but the use of WAZ < -3 led to an increased false-positive ratio up to 16·4 % (95 % CI (12·0, 20·9)) compared with 3·5 % (95 % CI (0·4, 6·5)) for MUAC < 115 mm alone. Conclusions: Frequent anthropometric measurements significantly improve the identification of malnourished children with a high risk of death without markedly increasing false positives. Combining two indices increases sensitivity but also increases false positives among children meeting case definitions.
  • Thumbnail Image
    Item
    Sex-ratio at birth in Nigeria: A demographic perspective
    (2022) Michel Garenne
    The study attempts at estimating the sex-ratio at birth in Nigeria. The study focuses on demographic surveys with complete maternity histories, including some 0.50 million births. It compares results with published estimates from births in health facilities and a few data from vital registration, including some 1.13 million births. Results from demographic surveys give an estimate of about 106 boys for 100 girls. There were no significant variations by large region in the country, and no significant trend over the years (1990-2018). Published estimates provided a similar value (106.2), with somewhat lower value in health facilities (105.3), and somewhat higher values in local vital registration (106.8), and major variations among available studies. Despite uncertainty, Nigeria appears to have higher sex-ratios than most African countries, with the exception of Ethiopia, and higher values than its five neighboring countries. Reasons for these high values of the secondary sex-ratio are discussed. (Afr J Reprod Health 2022;
  • Thumbnail Image
    Item
    Understanding Sex Differences in Childhood Undernutrition: A Narrative Review
    (2022-02-23) Susan Thurstans; Charles Opondo; Andrew Seal; Jonathan C. Wells; Tanya Khara; Carmel Dolan; André Briend; Mark Myatt; Michel Garenne; Andrew Mertens; Rebecca Sear; Marko Kerac
    : Complementing a recent systematic review and meta-analysis which showed that boys are more likely to be wasted, stunted, and underweight than girls, we conducted a narrative review to explore which early life mechanisms might underlie these sex differences. We addressed different themes, including maternal and newborn characteristics, immunology and endocrinology, evolutionary biology, care practices, and anthropometric indices to explore potential sources of sex differences in child undernutrition. Our review found that the evidence on why sex differences occur is limited but that a complex interaction of social, environmental, and genetic factors likely underlies these differences throughout the life cycle. Despite their bigger size at birth and during infancy, in conditions of food deprivation, boys experience more undernutrition from as early as the foetal period. Differences appear to be more pronounced in more severe presentations of undernutrition and in more socioeconomically deprived contexts. Boys are more vulnerable to infectious disease, and differing immune and endocrine systems appear to explain some of this disadvantage. Limited evidence also suggests that different sociological factors and care practices might exert influence and have the potential to exacerbate or reverse observed differences. Further research is needed to better understand sex differences in undernutrition and the implications of these for child outcomes and prevention and treatment programming.
  • Thumbnail Image
    Item
    Where Are the Demographic Dividends in Sub-Saharan Africa?
    (2023-09-20) Michel Garenne
    This paper reviews the concept of the demographic dividend and the empirical evidence therefor. The demographic dividend is mainly the result of fertility decline (lower number of births, lower population growth) which translates into a population age structure with a larger work force (age 15–64) and a smaller proportion of children (age 0–14), together with initially few elderly persons (age 65+). In turn, this favors economic growth, but it also has many consequences for households and for state budgets, as well as long-term consequences for population size and the environment. The first part of this paper shows the small correlations at the national macro-economic level between dependency ratios and economic growth. The second part shows the strong correlations at the household level between levels of fertility, child mortality and modern education. The third part discusses the many other correlates of the demographic dividend. The often-cited and controversial focus of the demographic dividend on economic growth hides many other positive effects of fertility control on households, on state budgets, and, in the long-run, on societies and the environment.
  • Thumbnail Image
    Item
    Where Are the Demographic Dividends in Sub-Saharan Africa?
    (2023-09-20) Michel Garenne
    This paper reviews the concept of the demographic dividend and the empirical evidence therefor. The demographic dividend is mainly the result of fertility decline (lower number of births, lower population growth) which translates into a population age structure with a larger work force (age 15–64) and a smaller proportion of children (age 0–14), together with initially few elderly persons (age 65+). In turn, this favors economic growth, but it also has many consequences for households and for state budgets, as well as long-term consequences for population size and the environment. The first part of this paper shows the small correlations at the national macro-economic level between dependency ratios and economic growth. The second part shows the strong correlations at the household level between levels of fertility, child mortality and modern education. The third part discusses the many other correlates of the demographic dividend. The often-cited and controversial focus of the demographic dividend on economic growth hides many other positive effects of fertility control on households, on state budgets, and, in the long-run, on societies and the environment.