Trends in world population: how will the millenium compare with the past?
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This paper reviews historical and projected trends in world population numbers, and the underlying determinants of those trends. Whereas the world's population has shown little change over most of its one million-year history, the past 200 years have witnessed dramatic changes in fertility, mortality and population growth rates. Recent decades, in particular, have seen unprecedented demographic events, with more people added to the world's population in the past 50 years than in the preceding million. The demographic impact of HIV/AIDS, selective as it is to young adults and infants, is also unprecedented, with life expectancy among some populations reduced by almost 20 years. As we approach the end of the 20th century, further demographic changes are underway with, for the first time in recent human history, a slowing down of world population growth. Nonetheless, world population is projected to grow from 6 billion currently to about 9.4 billion by 2050 (medium fertility assumption), with ageing emerging as the most pressing demographic issue facing humanity in the millenium. (+info)
Comparison of pituitary and recombinant human thyroid-stimulating hormone (rhTSH) in a multicenter collaborative study: establishment of the first World Health Organization reference reagent for rhTSH.
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BACKGROUND: The increasing use of recombinant-DNA-derived materials in therapy and diagnosis poses a new challenge for biological standardization, that of developing reference preparations appropriate for both the native and recombinant products. Here we report the results of an international collaborative study that was carried out under the auspices of WHO to assess the suitability of a preparation of recombinant thyroid-stimulating hormone (rTSH; 94/674) to serve as a potential standard for the calibration of diagnostic immunoassays compared with the International Reference Preparation (IRP) for human TSH (80/558). METHODS: Coded samples were provided to the 33 laboratories in the study, and participants were asked to perform TSH assays currently in use in their laboratories. Twenty-eight laboratories contributed 93 immunoassays in 41 different method-laboratory combinations, and an additional 5 laboratories contributed bioassay data. All data were analyzed centrally at the National Institute for Biological Standards and Control. RESULTS: The results obtained in different laboratories and with different assay systems revealed significant variability between estimates of rTSH relative to the IRP. These ranged from 5. 51 mIU (95% limits, 3.95-7.67 mIU) per ampoule by RIA to 7.15 mIU (95% limits, 6.7-7.63 mIU) per ampoule by immunofluorometric assay. However, the results showed that the assignment of a value of 6.70 mIU per ampoule of 94/674 would give reasonable continuity with the IRP in many assay systems. CONCLUSIONS: The preparation was established as the First WHO Reference Reagent for TSH, human, recombinant, to provide a means of validating assay performance and to maintain continuity with the IRP without compromising clinical data. (+info)
Education and the metabolic syndrome in women.
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OBJECTIVE: The main objective was to examine the association between the metabolic syndrome and socioeconomic position (as indicated by education) among women. RESEARCH DESIGN AND METHODS: The study sample comprised healthy women (aged 30-65 years) in Sweden who were representative of the general population in a metropolitan area. Socioeconomic position was measured by educational level (mandatory [< or = 9 years], high school, or college/university). The metabolic syndrome was defined as the presence of two or more of the following components: 1) fasting plasma glucose level > or = 7.0 mmol/l; 2) arterial blood pressure > or = 160/90 mmHg; 3) fasting plasma triglycerides > or = 1.7 mmol/l and/or HDL cholesterol < 1.0 mmol/l; and 4) central obesity (waist-to-hip ratio > 0.85 and/or BMI > 30 kg/m2). RESULTS: After adjustment for age, the risk ratio for the presence of the metabolic syndrome comparing the lowest (< or = 9 years) with the highest (college/university) education was 2.7 (95% CI 1.1-6.8). This association persisted after controlling for menopausal status, family history of diabetes, and behavioral risk factors. CONCLUSIONS: Low education is associated with increased risk for metabolic syndrome in middle-aged women. These findings show that not only are women with low socioeconomic position at increased risk for individual risk factors that are associated with cardiovascular disease and type 2 diabetes, they are also at increased risk for the metabolic clustering of risk factors. (+info)
Treatment in Kenyan rural health facilities: projected drug costs using the WHO-UNICEF integrated management of childhood illness (IMCI) guidelines.
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Guidelines for the integrated management of childhood illness (IMCI) in peripheral health facilities have been developed by WHO and UNICEF to improve the recognition and treatment of common causes of childhood death. To evaluate the impact of the guidelines on treatment costs, we compared the cost of drugs actually prescribed to a sample of 747 sick children aged 2-59 months in rural health facilities in western Kenya with the cost of drugs had the children been managed using the IMCI guidelines. The average cost of drugs actually prescribed per child was US$ 0.44 (1996 US$). Antibiotics were the most costly component, with phenoxymethylpenicillin syrup accounting for 59% of the cost of all the drugs prescribed. Of the 295 prescriptions for phenoxymethylpenicillin syrup, 223 (76%) were for treatment of colds or cough. The cost of drugs that would have been prescribed had the same children been managed with the IMCI guidelines ranged from US$ 0.16 per patient (based on a formulary of larger-dose tablets and a home remedy for cough) to US$ 0.39 per patient (based on a formulary of syrups or paediatric-dose tablets and a commercial cough preparation). Treatment of coughs and colds with antibiotics is not recommended in the Kenyan or in the IMCI guidelines. Compliance with existing treatment guidelines for the management of acute respiratory infections would have halved the cost of the drugs prescribed. The estimated cost of the drugs needed to treat children using the IMCI guidelines was less than the cost of the drugs actually prescribed, but varied considerably depending on the dosage forms and whether a commercial cough preparation was used. (+info)
The World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues. Report of the Clinical Advisory Committee meeting, Airlie House, Virginia, November, 1997.
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INTRODUCTION: Since 1995, the European Association of Pathologists (EAHP) and the Society for Hematopathology (SH) have been developing a new World Health Organization (WHO) Classification of hematologic malignancies. The classification includes lymphoid, myeloid, histiocytic, and mast cell neoplasms. DESIGN: The WHO project involves 10 committees of pathologists, who have developed lists and definitions of disease entities. A Clinical Advisory Committee (CAC)) of international hematologists and oncologists was formed to ensure that the classification will be useful to clinicians. A meeting was held in November, 1997, to discuss clinical issues related to the classification. RESULTS: The WHO has adopted the 'Revised European American Classification of Lymphoid Neoplasms' (R.E.A.L.), published in 1994 by the International Lymphoma Study Group (ILSG), as the classification of lymphoid neoplasms. This approach to classification is based on the principle that a classification is a list of 'real' disease entities, which are defined by a combination of morphology, immunophenotype, genetic features, and clinical features. The relative importance of each of these features varies among diseases, and there is no one 'gold standard'. The WHO Classification has applied the principles of the R.E.A.L. Classification to myeloid and histiocytic neoplasms. The classification of myeloid neoplasms recognizes distinct entities defined by a combination of morphology and cytogenetic abnormalities. The CAC meeting, which was organized around a series of clinical questions, was able to reach a consensus on most of the questions posed. The questions and the consensus are discussed in detail below. Among other things, the CAC concluded that clinical groupings of lymphoid neoplasms were neither necessary nor desirable. Patient treatment is determined by the specific type of lymphoma, with the addition of grade within the tumor type, if applicable, and clinical prognostic factors such as the international prognostic index (IPI). CONCLUSION: The experience of developing the WHO Classification has produced a new and exciting degree of cooperation and communication between oncologists and pathologists from around the world, which should facilitate progress in the understanding and treatment of hematologic malignancies. (+info)
The recent saga of cardiovascular disease and safety of oral contraceptives.
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This review presents detailed risk estimates from relevant epidemiological and other studies on the comparative safety of second and third generation oral contraceptives (OC). Written with the intention of presenting a repository of the available information, it also discourses briefly into the symptomatology and diagnosis of diseases associated with OC use and presents some of the critical comments made about various epidemiological analyses. A general critique including observations and opinions of various investigators completes the review. We stress that our own opinions on the various studies, or an attempt to adjudge the relative safety of second and third generation OC, are not given since they form the substance of our second paper which completes this symposium. (+info)
Safety of modern oral contraception: the options for women: lessons to be learned.
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The relatively short history of hormonal contraception has been marked by a series of 'pill scares', all of which--after creating panic among users--were proven to be unfounded in terms of public health impact. The latest pill scare, provoked by regulatory action in the United Kingdom and the Federal Republic of Germany in response to the publication of a series of articles indicating a doubling of risk of deep venous thrombosis in users of oral contraceptives containing third-generation progestins, seems finally settled: both the British and the German Drug Regulatory Authorities have now reverted their verdict. The damage unfortunately stays: hundreds of thousands of women have been compelled to abandon the pill of their choice, often deciding to drop contraception altogether, thereby exposing themselves to unwanted pregnancy and--in a number of cases--to pregnancy termination. This latest episode should be turned into something positive: we need to learn that, in the case of drugs in widespread use, before restrictive action is taken--and except for very rare and specific instances--the scientific community must carry out an exhaustive debate on the reality and importance of the observed effects. Although the public should, in each instance, be properly informed, it is only after this process has been completed that restrictive action should be taken. It is hoped that, after this last episode, all concerned have learned this simple principle and will accept being guided by it from now on. (+info)
Strategies for safe injections.
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In 1998, faced with growing international concern, WHO set out an approach for achieving injection safety that encompassed all elements from patients' expectations and doctors' prescribing habits to waste disposal. This article follows that lead and describes the implications of the approach for two injection technologies: sterilizable and disposable. It argues that focusing on any single technology diverts attention from the more fundamental need for health services to develop their own comprehensive strategies for safe injections. National health authorities will only be able to ensure that injections are administered safely if they take an approach that encompasses the whole system, and choose injection technologies that fit their circumstances. (+info)