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Managing data for a multicountry longitudinal study: Experience from the WHO Multicentre Growth Reference Study.
Food and Nutrition Bulletin. 2004; 25 Suppl 1:S46-S52.The World Health Organization (WHO) Multicentre Growth Reference (MGRS) data management protocol was designed to create and manage a large data bank of information collected from multiple sites over a period of several years. Data collection and processing instruments were prepared centrally and used in a standardized fashion across sites. The data management system contained internal validation features for timely detection of data errors, and its standard operating procedures stipulated a method of master file updating and correction that maintained a clear trail for data auditing purposes. Each site was responsible for collecting, entering, verifying, and validating data, and for creating site-level master files. Data from the sites were sent to the MGRS Coordinating Centre every month for master file consolidation and more extensive quality control checking. All errors identified at the Coordinating Centre were communicated to the site for correction at source. The protocol imposed transparency on the sites' data management activities but also ensured access to technical help with operation and maintenance of the system. Through the rigorous implementation of what has been a highly demanding protocol, the MGRS has accumulated a large body of very high-quality data. (author's)
Age misreporting in Malawian censuses and sample surveys: an application of the United Nations' joint age and sex score.
South African Journal of Demography. 1995; 5(1):11-17.The impact of age in demographic analyses, factors associated with age misreporting, the United Nations' procedure of evaluating age statistics and the application of this procedure to Malawian censuses are discussed. Although age reporting still remains inaccurate, there is some evidence to suggest a slight improvement in the quality of age reporting. Age misreporting varies from one region or district to another. These variations are explained in terms of the existing social, historical and cultural differences within the country. (author's)
Spiked. 2004 Feb 6;  p..Without doubt, the HIV infection has embedded itself in the African population, and the subsequent onset of AIDS is a tragedy and personal disaster for a large number of Africans and their families. However, I question whether the campaigns of organisations such as UNAIDS are having a more negative than positive effect - and I certainly doubt the veracity of the statistics being provided by UNAIDS and the World Health Organisation (WHO). (author's)
Geneva, Switzerland, World Health Organization [WHO], . 39 p.Reduction of maternal mortality has been endorsed as a key development goal by countries and is included in consensus documents emanating from international conferences such as the World Summit for Children in 1990, the International Conference on Population and Development in 1994 and, the Fourth World Conference on Women in 1995, and their respective five-year follow-up evaluations of progress in 1999 and 2000, the Millennium Declaration in 2000 and the United Nations General Assembly Special Session on Children in 2002. In order to monitor progress, efforts have to be made to address the lack of reliable data, particularly in settings where maternal mortality is thought to be most serious. The inclusion of maternal mortality reduction in the Millennium Development Goals (MDGs) stimulates increased attention to the issue and creates additional demands for information.1The first set of global and national estimates for 1990 was developed in order to strengthen the information base2. WHO, UNICEF and UNFPA undertook a second effort to produce global and national estimates for the year 1995.3 Given that a substantial amount of new data has become available since then, it was decided to repeat the exercise. This document presents estimates of maternal mortality by country and region for the year 2000. It describes the background, rationale and history of estimates of maternal mortality and the methodology used in 2000 compared with the approaches used in previous exercises in 1990 and 1995. The document opens by summarising the complexity involved in measuring maternal mortality and the reasons why such measurement is subject to uncertainty, particularly when it comes to monitoring progress. Subsequently, the rationale for the development of estimates of maternal mortality is presented along with a description of the process through which this was accomplished for the year 2000. This is followed by an analysis and interpretation of the results, pointing out some of the pitfalls that may be encountered in attempting to use the estimates to draw conclusions about trends.2,3 The final part of the document presents a summary of the kind of information needed to build a fuller understanding of both the levels and trends in maternal mortality and the interventions needed to achieve sustained reductions in the coming few years. (excerpt)
Washington, D.C., Negative Population Growth [NPG], 2003 Jun. 8 p. (NPG Forum)The United Nations Population Division has put the highlights of its new population estimates and projections onto the Web. Present world population is 6.3 billion. It is projected to rise to 8.9 billion by 2050, a number almost identical to the 1998 projection but 400-million-below-the-2000-version and slightly below the U.S. Census Bureau projection of 9.079 billion. The projection reflects (1) the expectation that fertility is heading below 2.1 in all but the poorest less developed countries (LDCs) and (2) the growing seriousness of AIDS. The new report represents an ongoing effort to bring the projections into line with recent experience. That process is still incomplete. Uncertainties internal and external to the calculations raise several questions: Will European fertility rise as anticipated? Will mortality continue to decline, particularly in the least developed countries, or will it rise and thus eventually bring population growth to a stop through the grim process of rising death rates rather than the benign process of reduced fertility? Do the projections still understate U.S. fertility and population growth? The report makes no effort to analyze the external forces that will affect mortality and migration. (excerpt)
Addis Ababa, Ethiopia, United Nations, Economic Commission for Africa [ECA], Population Division, 1993 Jun. 26 p.The present study on consistency between population projections prepared by the United Nations and selected [African ECA] member States found that differences, which were substantial for some countries, exist between the two sets of projections. The basic reasons for the differences [are] related to alternative assessments of: (a) the bench-mark data on population sizes and (b) the bench-mark estimates and projections on fertility, mortality and migration. (EXCERPT)
Mortality and attrition processes in longitudinal studies in Africa: an appraisal of the IFORD surveys.
POPULATION STUDIES. 1992 Jul; 46(2):327-48.The Institute for Demographic Training and Research (Institute de Formation et de Recherche Demographiques--IFORD) is a UN institution in Yaounde, Cameroon, which has been conducting longitudinal surveys since 1978 in urban areas of Africa to determine levels and characteristics of infant and child mortality. Longitudinal studies, however, lose original participants through attrition. Some critics assert that failing to adjust for this participant dropout may seriously bias study results. This study examines dropout characteristics to assess the degree of validity IFORD surveys hold as alternatives to indirect measurement technics. Employing 1978-81 IFORD survey data, relationships are explored between the initial characteristics of children in maternity units and different statuses of children identified by the IFORD surveys. Study results show no evidence that mortality or observed mortality differentials are biased by attrition. No relation was found between mortality and attrition in the survey, thereby suggesting that dropouts would have mortality experiences similar to those who remained in the study. Ignoring attrition, IFORD surveys may be used instead of indirect techniques to find levels and determinants of mortality in countries where registration systems and vital statistics are inaccurate. There is no need for such countries to wait for censuses or large-scale surveys to begin looking at infant mortality patterns. Specifically for Cameroon, the study revealed substantial mortality differentials by birth weight, ethnicity, place of delivery, and area of residence.
HEALTH POLICY AND PLANNING. 1992 Sep; 7(3):251-9.Policymakers and program managers rely on the oral rehydration solution (ORS) use rate as an indicator of program performance. The ORS use rate has several limitations, e.g., it disregards other program objectives. Other diarrheal disease control program objectives may include reducing the source of infection, promotion of effective home-based treatment, and training of health workers in appropriate diarrhea case management. WHO and the Demographic and Health Surveys (DHS) try to standardize the methodology for estimating ORS use rates, but they have not looked at them as cross-country indicators. Error sources lie in the terms used for diarrhea, the reference period, and the sequence of questions referring to treatment. In Bangladesh, the people recognize different types of diarrhea and treat each type differently. In 1 instance, health workers informed mothers to prepare and give a homemade sugar salt solution. Later they learned that mothers did not use ORS very much because they only used ORS for the type of diarrhea the health workers described. There has been considerable variation of ORS use rates in Bangladesh, perhaps because of the differences in meanings of the words used for diarrhea. The DHS uses a 2-week reference period, yet a Bangladesh survey finds underreporting of diarrheal episodes which occur early in the week of the survey. Other surveys do not use a specific reference period and mothers tend to remember only serious diarrheal episodes. A direct question about ORS use in surveys is too leading as indicated by higher ORS use rates when interviewers prompt respondents. ORS use rates do not give a true picture of a program and can even be counterproductive. No consensus exists as to what is high ORS use rate and what is low ORS use rate. Managers should not use ORS use rates as the only program indicator.
[Unpublished] 1991. Presented at the Society for Epidemiologic Research 24th Annual Meeting, Buffalo, New York, June 11-14, 1991. 12,  p.Health workers use anthropometry to determine the nutritional status of children. The accepted international growth reference curves provide the bases for the indices which include weight for height (W/H), height for age (H/A) and weight for age (W/A). Health workers must interpret these indices with caution, however. For example, W/H and H/A represent different physiological and biological processes while W/A combines the 2 processes. Further Z-scores, percentiles, or percent of median may be used as the scale for the indices and each scale has different statistical features. Specifically, Z-scores and percentiles acknowledge smoothed normalized distributions around the median, but the percent-of-median ignores the distribution around the median. Some researchers suggest using Z-scores rather than percentiles or percent-of-median since statisticians can interpret them more clearly and can calculate the proportion of children in the reference population who fall above or below a cut off point more easily. This cutoff should be only used to screen children who are likely to be malnourished since not all children below a cutoff are indeed malnourished. Some researchers have identified a leading limitation of the CDC/WHO based indices. A disjunction exists where the 2 smoothed based curves based on a population of <36 month old children from Ohio (longitudinal data) and another population of 2-18 year old children (cross sectional health surveys) meet. Further there is a reduction in age specific prevalences at 24 months. Thus some researchers recommend that anthropometry data be presented on an age specific basis, if age information is accurate. They further suggest that, if comparing data from different geographic areas, researchers should standardize age to have a summary measure. If age is not known the W/H summary measure should include 2 groups: <85 cm and =or+ 85 cm.
NEW ENGLAND JOURNAL OF MEDICINE. 1991 Mar 21; 324(12):848.Dr. Goodgame pleads for more openness in discussing the diagnosis of AIDS with the patient. On the other hand, he believes testing for HIV antibodies is largely unnecessary for diagnosis in Uganda, which has 1 of the highest prevalences in the world. Given, however, that the WHO clinical AIDS definition has a positive predictive value of 73% in Ugandan patients (or 83% if cough due to tuberculosis is excluded), 27% of patients in whom there is a clinical suspicion will be erroneously told they have AIDS--"dreadful and at times almost unbearable" news. In other parts of Africa with a lower prevalence this may be even less acceptable. In Gemena, northern Zaire, we evaluated the WHO clinical Aids definition, as modified by Colebunders et al., in 166 patients in 1988-1989. The positive predictive value was 61% (67% if patients with tuberculosis were excluded). This means a wrong diagnosis of AIDS in 1 of every 3 patients. The HIV seroprevalence in this population was 7.9%, as measured in a group of 340 healthy pregnant women. Another problem is the lack of sensitivity of the clinical case definition of AIDS, leading to the possible exclusion of 30-46% of African patients with HIV-related disease in the absence of testing for HIV antibodies. Many patients with AIDS would thus escape detection until they were ill enough to meet the diagnostic criteria. If a standard of care for patients with AIDS is to be achieved in Africa, as Dr. Goodgame proposes, correctly identifying the patients early in the course of the disease is necessary, and we do not believe this is possible without laboratory confirmation. We are aware of the problems that may arise when anti-HIV testing is introduced, and the questions raised (e.g. Who will be tested? What will be done when a positive result is found?) should be thoroughly discussed with the local health team before the test is introduced. In addition, screening of blood donors should have absolute priority over diagnostic testing if a choice has to be made because of the dearth of reagents. (full text)
Use of HIV surveillance data in national AIDS control programmes. A review of current data use with recommendations for strengthening future use.
[Unpublished] 1990. , 12 p. (WHO/GPA/SFI/90.1)The sentinel serosurveillance method, proposed by WHO in 1988 for monitoring HIV infection, uses repeated sampling at designated sites for selected groups to monitor current and projected trends in HIV incidence and spread. Such information is necessary to promote political and financial commitment to the control of HIV, to focus control efforts, to develop intervention strategies, and to promote further research. The sentinel surveillance methodology is especially appropriate for identifying differences in HIV prevalence between groups and locations. The method's use of unlinked or blind testing minimizes self-selection bias and protects confidentiality. The sampling frequency should be based on the estimated HIV incidence in a given location and the actions to be initiated by the program when a certain threshold (e.g., a prevalence exceeding 0.5%) is reached or crossed. The less expensive, less intensive lot quality assurance sampling method can be used in situations where HIV prevalence is below threshold levels; however, greater precision is required at core sentinel sites where serologic studies aimed at developing or evaluating interventions are in progress. In all situations, a basic question is, what action will be taken once the threshold is reached? A possible approach is to intensify counseling and voluntary testing programs when prevalence in high-risk groups such as prostitutes or sexually transmitted disease patients reaches the threshold and to expand surveillance to other populations and/or areas.
Evaluation of the World Health Organization clinical case definition of AIDS among tuberculosis patients in Kinshasa, Zaire [letter]
JOURNAL OF INFECTIOUS DISEASES. 1989 Nov; 160(5):902-3.Although the World Health Organization (WHO) clinical case definition for AIDS has been confirmed to have fair sensitivity, specificity, and positive prediction value in sub-Saharan Africa, its application among tuberculosis patients at the Makala Sanatorium in Kinshasa, Zaire, were evaluated in terms of this case definition by physicians who were not aware of their human immunodeficiency virus (HIV) serostatus. Screening for HIV-1 enzyme-liked immunosorbent assay (ELISA) and Western blot indicated that 85 (36%) of these patients were HIV-positive. In this population, the WHO clinical case definition had a sensitivity of 33%, a specificity of 86%, and a positive predictive value of 58% for HIV infection. When the case definition was modified to exclude chronic cough in tuberculosis patients as a minor criterion, the sensitivity decreased to 18% and the specificity and positive predictive value increased to 97% and 77%, respectively. A possible explanation for the low sensitivity of the WHO clinical case definition of HIV infection among tuberculosis patients is that tuberculosis may be an early manifestation of immunosuppression that precedes other signs and symptoms of AIDS. It is also possible that the chemotherapy administered to tuberculosis patients eliminates symptoms contained in the WHO case definition such as fever, cough, weight loss, and lymphadenopathy. These findings suggest that periodic serosurveys of tuberculosis patients may be more effective than use of the WHO clinical case definition in detecting HIV infection.
In: Infant and childhood mortality and socio-economic factors in Africa. (Analysis of national World Fertility Survey data) / Mortalite infantile et juvenile et facteurs socio-economiques en Afrique. (Analyse des donnees nationales de l'Enquete Mondiale sur la Fecondite), [compiled by] United Nations. Economic Commission for Africa [ECA]. Addis Ababa, Ethiopia, United Nations, ECA, 1987. 7-26. (RAF/84/P07)Technical problems and methods associated with the analysis of differential child mortality data for a conference of representatives from 8 African countries, sponsored by the UN Economic Commission for Africa and the International Statistical Institute are described. The data being interpreted were from the World Fertility Surveys, conducted between 1977 and 1981, including complete birth histories of women up to 50 years of age. A core questionnaire contained 7 sections on woman's background, maternity history, contraceptive knowledge and marriage history, fertility regulation, work history and husband's background. Mortality was measured by Brass methods and the cohort approach with analysis of determining factors. No adjustment was made for omission of births and of dead children: since underreporting is more likely to occur in the past, current mortality estimates can be considered fairly accurate. Methods of correcting for misreporting are described. The extent of potential bias due to lack of data on children whose mothers were deceased at the time of survey is unknown. Another source of bias is truncation due to loss of data on older children born to older women. Generally the quality of the World Fertility Survey mortality data is reasonably good, compared to other studies.
Washington, D.C., SOMARC, .  p.This document contains briefing materials for the participants of an upcoming meeting of the advisory council and working groups of Social Marketing for Change (SOMARC), an organizational network, funded by the US Agency for International Development (USAID) and composed of 5 firms which work together in helping agencies, organizations, and governments develop contraceptive social marketing programs. Social marketing is the use of commercial marketing techniques and management procedures to promote social change. The briefing materials include 3 background and 18 issue papers. The background papers provide brief summaries of USAID's population activities and of the history of social marketing programs, an overview of USAID sponsored contraceptive social marketing programs in 14 countries and of 3 major non-USAID programs, and a listing of the skills and resources needed to develop effective contraceptive social marketing programs. The issue papers provide a focus for the discussion sessions which are scheduled for SOMARC's working groups on marketing communication, management, and research. USAID's objective is to promote the development of family planning programs which are completely voluntary and which increase the reproductive freedom of couples. Contraceptive social marketing programs are consistent with this objective. USAID provides direct funding for family planning programs as well as commodity, technical, and training support. USAID's involvement in social marketing began in 1971, and USAID is currently sponsoring programs in Jamaica, Bangladesh, Nepal, El Salvador, Egypt, Honduras, Ecuador, the Caribbean Region, Costa Rica, Guatemala, and Peru. In the past, USAID provided support for programs in Mexico, Tunisia, and Ghana. The Mexican project is now functioning without USAID support, and the projects in Tunisia and Ghana are no longer operating. Major non-USAID contraceptive social marketing programs operate in India, Sri Lanka, and Colombia. These programs received only limited technical support from USAID. To ensure the success of social marketing programs, social marketers must have access to the knowledge and skills of commercial marketers in the areas of management, analysis and planning, communications, and research. Social marketers must also have expertise in social development and social research. In reference to the issue papers, the working groups and the advisory council were asked to develop suggestions for 1) overcoming social marketing program management problems, 2) motivating health professionals toward greater involvement in social marketing programs, 3) improving the media planning component of the programs, 4) improving management stability and training for management personnel, and 5) improving program evaluation. Areas addressed by the issue papers were 1) whether social marketing programs should be involved in creating a demand for contraceptives or only in meeting the existing demand, 2) the development of a methodology for assessing why some programs fail and others succeed, 3) the feasibility of using anthropological and questionnaire modules for conducting social marketing research, 4) techniques for overcoming the high level of nonsampling error characteristic of survey data collected in developing countries, 5) techniques for identifying contraceptive price elasticity, 6) the feasibility of using content analysis in social marketing communications, 7) the applicability of global marketing strategies for social marketing, and 8) how to select an an appropriate advertising agency to publicize social marketing programs.
[Reconciling censal and inter-censal data and determination of the population base] Conciliacion censal y determinacion de la poblacion base.
In: Metodos para proyecciones demograficas [compiled by] United Nations. Centro Latinoamericano de Demografia [CELADE]. San Jose, Costa Rica, Centro Latinoamericano de Demografia, 1984 Nov. 13-42. (Centro Latinoamericano de Demografia [CELADE] Series E, No. 1003)This work describes procedures used by the Latin American Demographic Center (CELADE) for establishing a base population for projection in quinquennial age groups by means of evaluation of population censuses and reconciliation of demographic data for 2 or more intercensal periods. Demographic reconciliation refers to the array of procedures through which the degree of coverage of successive censuses is evaluated; age and sex distributions resulting from incomplete coverage, differential omission, and poor age reporting are corrected; the demographic dynamics of intercensal periods are made coherent with estimates of mortality, fertility, and migration from all available sources; and a base population for population projection is established. There are no fixed rules for evaluation and reconciliation of census data, because the history and quality of data collection in each country are unique. The compensatory equation, in which 2 or more population censuses are reconciled in regard to fertility, mortality, and international migration in intermediate years usually in terms of age cohorts, is an indispensable tool for demographers in developing countries. The need to add children born in the years between censuses and the different types of errors typifying different age groups means that the process of census reconciliation should be carried out separately for at least 3 age groups: children under 5, the 5-9 year cohort, and those over 10 years of age. The age group 0-4 is often the most seriously underestimated. Because the age group 5-9 years is often the best enumerated in Latin American population censuses, it can serve as the basis for correction of the population aged 0-4. The data required include the population aged 5-9 in single years in the last census, the deaths in children under 10 by year of birth and age at death in single years, and the annual number of births in the 10 years preceding the last census. Data from Panama illustrate that the results of this technique are not always acceptable, in which case correction of the 0-4 cohort may be accomplished by means of correction of births and deaths using indirect methods. Corrections for the 5-9 cohort, if required, can be made in a similar manner to that for the youngest group. Evaluation and correction of errors of omission and misreporting of age of the population over 10 is the most difficult because data sources are most often inadequate, these age groups have the greatest age and sex differentials and poorest age reporting, and are most likely to be effected by emigration. All available data should be utilized to produce a group of alternative estimates for each cohort based on diverse basic data and assumptions about such variables as the sex ratios for age agroups. The most likely values must then be selected or calculated. The process by which census results from 1950-80 were used to estimate the base population for a projection by components in Panama illustrates the procedure used by CELADE.
In: United Nations. Economic and Social Commission for Asia and the Pacific, World Fertility Survey, and International Institute for Population Studies. Regional Workshop on Techniques of Analysis of World Fertility Survey data: report and selected papers. New York, UN, 1979. 15-36. (Asian Population Studies Series No. 44)The World Fertility Survey provides data from national maternity history inquiries. Detecting trends and differentials is only as accurate as the data collected. Where evidence suggests error, the analysis may be restricted to obtaining only a measure of fertility level. The basic data is the date and order of birth of each live born child for a sample of women in the reproductive period, according to the current age of the women and their duration of marriage. The cohort marker is usually separated into 7 5-year classes determined by age at interview; sample of women is representative of the female population of childbearing age. Total births for each cohort are allocated to different periods preceding the survey date. Reading down the columns gives the births to different cohorts over different ranges in the same time interval preceding the survey. To detect omissions, check the overall sex ratio and the sex ratios by periods; examine the trends of infant mortality by cohorts and periods; an excess of male mortality over female indicates poor reporting of dead female children and/or of sex (a common omission). From data on age of mother and number of surviving children at the survey and estimates of mortality level, the numbers of births at preceding periods may be calculated.
SOTSIOLOGICHESKIE ISSLEDOVANIIA. 1982 Oct-Dec; 9(4):124-6.Within the framework of a UN resolution calling for censuses to be carried out in all countries of the world between 1975-1985, the Peoples Republic of China allocated 360 million yuan and used 15.6 million dollars of UN funding to prepare for conducting their census beginning in July 1982. The 1st census of the Chinese mainland was in 1953, showing a population of 601 million. By the beginning of the 1980s, UN estimates put the count at 1.02 billion, an increase of 420 million in 30 years, 1/2 of which are under the age of 20. The new census form includes more questions, and to prevent errors it will be taken twice, first by local census takers and then by census takers from outside the local area. Within the larger cities the 2nd census from previous census counts determined % error in size of population and a .17% error in place of birth. In backward areas the errors are respectively .09 and 4%. Full tabulation should be completed by June 1984, and a report of final results should be forthcoming by the end of 1985. An important aim of the census is to consolidate controls over population growth and to enforce further the rule of "1 woman, 1 child," which, although it has succeeded in dropping the population growth rate from 2.34 to 1.17 since 1971, now faces the problem of hundreds of millions of young Chinese born during the 1950s and 1960s reaching marriageable age. The census faces problems of weak communications and low education level among the populace, as well as resistance from local leaders, who are already heavily burdened with projects.