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Michel Garenne

Publications and source records attributed to Michel Garenne.

14 recordsLinked to original sources
PubMed2006

Health transitions in sub-Saharan Africa: overview of mortality trends in children under 5 years old (1950-2000).

OBJECTIVE: To reconstruct and analyse mortality trends in children younger than 5 years in sub-Saharan Africa between 1950 and 2000. METHODS: We selected 66 Demographic and Health Surveys and World Fertility Surveys from 32 African countries for analysis. Death rates were calculated by yearly periods for each survey. When several surveys were available for the same country, overlapping years were combined. Country-specific time series were analysed to identify periods of monotonic trends, whether declining, steady or increasing. We tested changes in trends using a linear logistic model. FINDINGS: A quarter of the countries studied had monotonic declining mortality trends: i.e. a smooth health transition. Another quarter had long-term declines with some minor rises over short periods of time. Eight countries had periods of major increases in mortality due to political or economic crises, and in seven countries mortality stopped declining for several years. In eight other countries mortality has risen in recent years as a result of paediatric AIDS. Reconstructed levels and trends were compared with other estimates made by international organizations, usually based on indirect methods. CONCLUSION: Overall, major progress in child survival was achieved in sub-Saharan Africa during the second half of the twentieth century. However, transition has occurred more slowly than expected, with an average decline of 1.8% per year. Additionally, transition was chaotic in many countries. The main causes of mortality increase were political instability, serious economic downturns, and emerging diseases.

Africa South of the Sahara↗
PubMed2006

Premarital fertility in Namibia: trends, factors and consequences.

Premarital fertility, defined as fertility before first marriage, was found to be highly prevalent in Namibia. According to data from the 1992 and 2000 DHS surveys, the proportion of premarital births was 43% for all births, and 60% for the first birth. This seemed to be primarily due to a late mean age at first marriage (26.4 years) and low levels of contraception before first marriage. Data were analysed using a variety of demographic methods, including multiple decrement life table and multivariate logistic models. Major variations were found by ethno-linguistic groups: Herero and Nama/Damara had the highest levels of premarital fertility (above 60%); Ovambo and Lozi had intermediate levels of premarital fertility (around 40%); Kavongo and San appeared to have kept a more traditional behaviour of early marriage and low levels of premarital fertility (around 20%). The largest ethno-linguistic group, the Ovambo, were in a special situation, with fast increasing age at marriage and average level of premarital fertility. Whites and mixed races also differed, with Afrikaans-speaking groups having a behaviour closer to the average, whereas other Europeans had less premarital fertility despite an average age at marriage. Ethnic differences remained stable after controlling for various socioeconomic factors, such as urbanization, level of education, wealth, access to mass media, and religion. Results are discussed in light of the population dynamics and political history of Namibia in the 20th century.

Adolescent↗
PubMed2006

Distributions of mortality risk attributable to low nutritional status in Niakhar, Senegal.

This study proposes a method for computing the distributions of mortality risk attributable to malnutrition among children of developing countries. Population distributions of nutritional status were adjusted with a normal curve and the relation between mortality and nutritional status was fitted with a linear logistic model after controlling for age. The attributable risk for mortality could therefore be computed at any threshold of low nutritional status. The method was applied in Niakhar, Senegal, where a comprehensive study of the relation between nutritional status and mortality was conducted in 1983-1984 on approximately 5,000 children, 6-59 mo of age. The anthropometric indicators used were Z-scores of weight-for-age, weight-for-height, height-for-age, head circumference-for-age, arm circumference-for-age, triceps skinfold-for-age, and subscapular skinfold-for-age, plus arm circumference, body mass index, and 2 composite indicators. Population attributable fraction varied according to indicators selected and ranged from 31% (head circumference) to 65% (arm circumference). The 2 composite indicators summarizing the whole nutritional status provided the same value for the population attributable fraction (59 and 60%, respectively). Classic thresholds of mild, moderate, and severe malnutrition are presented, as well as the bivariate distribution of wasting and stunting. Whatever the indicator used, mortality attributable risks appeared evenly distributed along the scale of low nutritional status. Our findings question the value of using classic thresholds of mild, moderate, and severe malnutrition (developed by clinicians for practical purposes) for nutritional epidemiology.

Child, Preschool↗
PubMed2004

Decrease in measles virus-specific CD4 T cell memory in vaccinated subjects.

Since the licensure and generalization of an effective measles virus (MV) vaccine 41 years ago, antibody levels have been used as correlates of immunity. The long-lived MV-specific antibody response has been studied intensely, but the dynamics of MV-specific T cell immunity over time have not been well characterized. We thus characterized the profiles of MV vaccine-induced antigen-specific T cells over time since vaccination. In a cross-sectional study of healthy subjects with a history of MV vaccination, we found that MV-specific CD4 and CD8 T cells could be detected up to 34 years after vaccination. The levels of MV-specific CD8 T cells and MV-specific IgG remained stable, whereas the level of MV-specific CD4 T cells decreased significantly in subjects who had been vaccinated >21 years earlier. These results show that MV-specific T cell immunity after vaccination is long lasting and reveal different dynamics between CD4 and CD8 cells after vaccination.

Adolescent↗
PubMed2004

Fertility trend and pattern in a rural area of South Africa in the context of HIV/AIDS.

Little is known about the dynamics of fertility transition in South Africa, though recent studies have begun to shed light on demographic changes in the country. This study presents trends and patterns of fertility observed in a rural South African population. Various demographic and statistical techniques were used to examine fertility patterns in a population of 21,847 women in a rural KwaZulu-Natal (KZN) demographic surveillance area. These are compared with patterns seen in another South African rural population under demographic surveillance, and with data from the 1998 South Africa Demographic and Health Survey. Findings are interpreted in light of contraceptive use patterns and HIV prevalence in the population. In South Africa, the end of the fertility transition is now in sight. In rural KZN, where national fertility levels are highest, fertility has declined rapidly for about two decades and would have reached below replacement level in 2003. While fertility has declined rapidly among all women over age 18 years, fertility levels among adolescents have not changed in decades. Although most adolescents in rural KZN were sexually active (60%), few had ever used contraception (200%). High HIV seroprevalence appears to explain a small part of the fertility decline (12%); however, this effect is likely to grow in the near future as the HIV/AIDS epidemic continues in South Africa. If the current trends continue in the future, below replacement fertility, together with high mortality due to AIDS, it could soon lead to negative natural population growth in rural South Africa.

Adolescent↗
PubMed2003

Sex differences in health indicators among children in African DHS surveys.

The study analyses various sex differences observed among children in WFS and DHS surveys conducted in sub-Saharan Africa. Four outcome indicators are presented: neonatal mortality, postneonatal mortality, child mortality and prevalence of malnutrition. Three indicators of health seeking behaviour are presented: vaccination, oral rehydration therapy and duration of breast-feeding. The statistical analysis focuses on comparison of the observed distributions of the sex ratios to theoretical distributions expected from the sample sizes of the various surveys. The results show the absence of any difference in health seeking behaviour between boys and girls, whether for preventive medicine (vaccination), curative medicine (oral rehydration therapy) or feeding practices (breast-feeding). On the other hand, mortality appears to be consistently higher for boys, more so among neonates (+28%) than among 1-12-month-olds (+8%) and 1-4-year-olds (+4%), and similarly malnutrition appears to be more prevalent among boys (+5%%). The contrast between the lack of differences in behavioural indicators and the significant differences in outcome indicators suggests a biological causality. Results are discussed in the light of biological factors.

Africa↗
PubMed2003

The association between protein-energy malnutrition, malaria morbidity and all-cause mortality in West African children.

Both malaria and protein-energy malnutrition (PEM) are highly prevalent in young children of sub-Saharan Africa, and the association between PEM and malaria continues to be discussed controversially. We analysed the association between PEM, malaria morbidity and all-cause mortality in a cohort of 709 children aged 6-30 months in a malaria holoendemic rural area of Burkina Faso. Study children were followed over the main malaria transmission period (June-December) in 1999 through longitudinal malaria surveillance complemented by three cross-sectional clinical surveys. There was no association between PEM and malaria morbidity, but malnourished children had a more than two-fold higher risk of dying than non-malnourished children.

Anthropometry↗
PubMed2003

A wealth index to screen high-risk families: application to Morocco.

This study defined a wealth index that was strongly correlated with a health indicator: the survival of children aged less than five years. This index allowed the most vulnerable social groups for health outcomes to be identified. These groups could become the target for focused interventions and in particular for health-insurance schemes. The study was based on a thorough analysis of data collected in Morocco in the 1992 Demographic and Health Survey (DHS). Results of the analysis showed that a simple score based on 15 socioeconomic indicators provided a proper discriminatory tool for screening families at higher risk of infant and child mortality. The score was based on characteristics of housing and household goods which are easy to collect in the field. The scoring system was shown to be as powerful as more complex statistical techniques, such as discriminant analysis. It could be used for determining who could be eligible for free health insurance.

Child, Preschool↗
PubMed2002

Sex ratios at birth in African populations: a review of survey data.

This study analyzes the distribution of sex ratio at birth in African populations using data collected in birth histories in sample demographic surveys (Demographic and Health Surveys and World Fertility Surveys). The average sex ratio from 56 surveys, totaling 1.130 million births, was 1.033 (95% CI, 1.029-1.037), significantly different from the world average of 1.055. The distribution of sex ratios across surveys was found to be heterogeneous, and different from what could have been expected from random fluctuations due to sample size. Three subsets were identified: a subset with lower sex ratios, primarily in countries of eastern and southern Africa of Bantu populations (1.010), a subset with average sex ratios (1.035), and a subset of countries with higher sex ratios, in particular Nigeria and Ethiopia (1.070). Further analysis revealed that African populations are as diverse as other populations, with sex ratios ranging from low values (below 1.00) to high values (above 1.08). Results are discussed in light of independent data sources and in comparison with other human populations.

Adolescent↗
PubMedDate not supplied

[Why drug prices are high in sub-Saharan Africa. Analysis of price structure: the case of Senegal].

This article seeks to shed light on the reasons for the lack of correlation between the price of drugs in this very poor sub-Saharan country and the population's ability to pay for them. The analysis is based on: (i) a comparison between the wholesale (exclusive of VAT and other taxes) and government-fixed retail prices and the corresponding prices of the same drugs in their country of origin (France); (ii) a description of the price-setting mechanisms in Senegal in both the public and private sectors; and (iii) an evaluation of public-sector retail price in Senegal, by end users and prescribing professionals in both sectors. The study found that: (i) patient expenditure would be one-fifth as high if all the drugs in the sample were sold at their government-fixed public-sector retail prices; (ii) the most cost effective drugs are sold at fixed retail prices higher than those of drugs not reimbursed by the national health insurance in France because considered less cost-effective; (iii) the mechanism for setting public retail prices seems to be unrelated to public health objectives, does not consider specific population groups, target diseases, or the drugs' therapeutic value, and therefore cannot be considered an effective tool for implementing national drug policies. Instead, the incentives of this mechanism lead retailers to sell the most expensive drugs first, to generate the highest possible margins. It does not prioritize the essential generic drugs that health authorities have placed at the centre of their pharmaceutical policy.

Africa South of the Sahara↗
PubMedDate not supplied

[Measuring drug affordability (Senegal)].

This article presents the results of a global survey on drug accessibility conducted in Senegal in 2001. The original tool we developed to measure drug affordability for this study considered 5 marker diseases and their corresponding medical treatments and determined the theoretical amount that each population quintile can devote to the purchase of these treatments at market prices without damaging their economic status (affordability threshold). These results were then compared with those obtained as part of a field survey of 987 patients at 41 health centres and 51 private chemists (pharmacists). The main results show that the population's ability to afford treatment is low (less than 40% at public sector prices and a little over 20% at private sector prices) and that even at the lowest market prices (public sector) 20% to 60% of the population cannot afford treatments for the most common illnesses. The field survey shows, moreover, that these results are exacerbated by four external factors: additional illness-associated expenditures (i.e., transportation costs, doctor visits), lack of compliance with government-set drug prices, prescription habits and dispensing practices. When these added costs are taken into account, less than 20% of the population can actually pay the public-sector treatment costs for the marker diseases, let alone the private sector prices. This tool is also useful for highlighting the insufficiencies of the strategies adopted for the target diseases (inconsistency between pricing policies and health priorities) and for providing a baseline measurement (at t0) of different socioeconomic groups' access to given treatments. Improvement or deterioration can then be assessed with measurements at times t1, t2...tn.

Costs and Cost Analysis↗