OpenUCT :: Browsing by Subject "Demography"

Browsing by Subject "Demography"

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Open Access
Addison's disease symptoms - a cross sectional study in urban South Africa
(Public Library of Science, 2013) Ross, Ian Louis; Levitt, Naomi S
BACKGROUND: Addison's disease is a potentially life-threatening disorder, and prompt diagnosis, and introduction of steroid replacement has resulted in near normal life-expectancy. There are limited data describing the clinical presentation of Addison's disease in South Africa. It is hypothesised that patients may present in advanced state of ill-health, compared to Western countries. Patients A national database of patients was compiled from primary care, referral centres and private practices. 148 patients were enrolled (97 white, 34 mixed ancestry, 5 Asian and 12 black). METHODS: Demographic and clinical data were elicited using questionnaires. Biochemical data were obtained from folder reviews and laboratory archived results. RESULTS: The majority of the cohort was women (62%). The median and inter-quartile age range (IQR) of patients at enrolment was 46.0 (32.0-61.0) years, with a wide range from 2.8-88.0 years. The median and IQR age at initial diagnosis was 34.0 (20.0-45.0) years (range 0.02-77.0) years, indicating that at the time of enrolment, the patients, on average, were diagnosed with Addison's disease 12 years previously. Hyperpigmentation was observed in 76%, nausea and vomiting occurred in more than 40%, and weight loss was noted in 25%. Loss of consciousness as a presenting feature was recorded in 20 %. with a 95% confidence interval [CI] of (14-28%) and shock occurred in 5% CI (1.5-8.5%). Case-finding was recorded at 3.1 per million. CONCLUSIONS: The usual constellation of hyperpigmentation, nausea, vomiting and weight loss suggests Addison's disease, but a significant proportion present with an advanced state of ill-health and Addisonian crises. A lower prevalence rate, compared to Western countries is suggested.
Open Access
Analysis of the projected parity progression ratio method using two successive censuses
(2013) Mutakwa, Darlington; Moultrie, Tom
The objective of this study is to assess how well the projected parity progression ratio method works when applied to two successive censuses or Demographic Health Surveys. Four countries, namely Malawi, Zimbabwe, Cambodia and Panama, each with two recent censuses which are ten years apart, are used. Each of the census and survey used is taken through a data quality assessment process to check for inconsistencies. Using age-order specific fertility rates derived from births in the past year, parity progression ratios are projected to the next census.
Open Access
As long as they don't bury me here : social relations of poverty in a Southern African shantytown
(2008) Tvedten, Inge; Spiegel, Andrew; Ross, Fiona C
Focusing on four shantytowns in the northern Namibian town of Oshakati, this study analyses the coping strategies of the poorest sections of such populations. I ask what it is that enables some people living in oppressed and poor urban shantytowns to strive to go on with their lives or improve their situation, while others living in the same context and under the same conditions seem trapped in chronic poverty and apparently give up making much of their lives? The study is based on fieldwork conducted intermittently from 1991 to 2001, using qualitative anthropological methods supplemented by quantitative measures of material poverty. It combines theories of political, economic and cultural structuration, and of the material and cultural basis for social relations of inclusion and exclusion as practise.
Open Access
An assessment of the feasibility of using administrative data in producing mid-year population estimates for South Africa
(2015) Hlabano, Mbongeni Charles; Dorrington, Rob
The production of mid-year population estimates is an important undertaking which informs various stakeholders in policy formation and decision making. For instance, national governments use mid-year estimates to allocate seats in parliament to various constituents and public health sectors use them to monitor and improve service delivery. Mid-year population estimates undoubtedly serve very important purposes that affect lives of many people. As such, national statistical offices in various countries are given the mandate to produce annual mid-year population estimates. Statistics South Africa (Stats SA) assumes the function of producing and publishing official mid-year estimates of the population in South Africa. Stats SA produces its mid-year estimates using DemProj, population projection software which is part of the SPECTRUM suite of policy models developed by the Futures Institute. However, Stats SA does not publish full details of its adaptation of DemProj when producing its mid-year estimates as it regards this as proprietary. Concerns have been raised about the accuracy of the official mid-year estimates in terms of age distribution, particularly for ages below 40 last birthday in 2011 (e.g. Dorrington 2013). As such, this research critically analyses the method used by Stats SA to produce mid-year estimates and assesses the feasibility of using administrative data to produce mid-year estimates for South Africa. The base population is adapted from the 2001 census population. Birth and death registration data are used in a cohort component approach to produce alternative mid-year estimates for South Africa for the years 2002-2011. Prior to using these data, they are adjusted for incompleteness of registration. Levels of completeness of birth and death registration are estimated by extrapolating earlier estimates of completeness from various researchers. The mid-year estimates obtained are compared with those published by Stats SA in order to assess the relative quality of the two series of mid-year estimates. The mid-year estimates for 2011 are also compared with the mid-year population estimated from the 2011 census. These comparisons help identify the mismatches to the census and their possible causes and as such, these may lead to improved population estimates in the future, and a viable alternative method to that currently being used by Stats SA.
Open Access
Assessment of the IGME methods of estimating infant mortality rate and neonatal mortality rate from under-five mortality rate in countries affected by HIV
(2012) Ayalew, Kassahun Abere; Dorrington, Rob
This study assesses the UN Inter-agency Group for Child Mortality Estimation (IGME) methods of estimating the infant and neonatal mortality rates from the under-five mortality rates in countries affected by HIV/AIDS. It uses Botswana, Malawi and South Africa as case studies. The assessment is made by comparing the IGME results with estimates from projection models and empirical results computed from survey data and vital statistics data corrected for the level of incompleteness for the countries included in the study. In addition, relevant literature is reviewed in order to determine the reasonableness and impact (on the results produced) of the assumptions made by the method.
Open Access
Assessment of the robustness of recent births in estimating infant mortality using multi-country Demographic Health Survey data
(2014) Munjoma, Malvern; Moultrie, Tom; Dorrington, Rob
This dissertation investigates the robustness of recent births in estimating infant mortality rates from the proportion of deaths observed among births reported in a 24month period. The Blacker Brass technique is applied to all births reported in the 24month period and to most recent births in the 24 month period. The study uses birth history data from 76 Demographic and Health Surveys conducted in 16 countries across the developing world between 1986 and 2011. All births (and the deaths of those births) occurring in five 2-year periods before each survey were extracted to obtain five estimates of infant mortality using the Blacker-Brass and direct estimation methods from each dataset. This allows trends in infant mortality for the 10-year period before the survey to be compared and relative errors to be calculated. The results showed a decline in infant mortality in most datasets and are consistent with the United Nations and the World Health Organisation 2013 estimates. The relative errors did not indicate any systematic bias of the Blacker-Brass method applied to all births; however, further investigations showed that the method underestimated infant mortality in the period closest to the survey date in most datasets. Furthermore, the relative errors were positively correlated with the directly estimated level of infant mortality. There were, however, no significant differences in the relative errors across countries.
Open Access
The association between hypertension and depression and anxiety disorders: results from a nationally-representative sample of South African adults
(Public Library of Science, 2009) Grimsrud, Anna; Stein, Dan J; Seedat, Soraya; Williams, David; Myer, Landon
Objective: Growing evidence suggests high levels of comorbidity between hypertension and mental illness but there are few data from low- and middle-income countries. We examined the association between hypertension and depression and anxiety in South Africa. METHODS: Data come from a nationally-representative survey of adults (n = 4351). The Composite International Diagnostic Interview was used to measure DSM-IV mental disorders during the previous 12-months. The relationships between self-reported hypertension and anxiety disorders, depressive disorders and comorbid anxiety-depression were assessed after adjustment for participant characteristics including experience of trauma and other chronic physical conditions. RESULTS: Overall 16.7% reported a previous medical diagnosis of hypertension, and 8.1% and 4.9% were found to have a 12-month anxiety or depressive disorder, respectively. In adjusted analyses, hypertension diagnosis was associated with 12-month anxiety disorders [Odds ratio (OR) = 1.55, 95% Confidence interval (CI) = 1.10-2.18] but not 12-month depressive disorders or 12-month comorbid anxiety-depression. Hypertension in the absence of other chronic physical conditions was not associated with any of the 12-month mental health outcomes (p-values all <0.05), while being diagnosed with both hypertension and another chronic physical condition were associated with 12-month anxiety disorders (OR = 2.25, 95% CI = 1.46-3.45), but not 12-month depressive disorders or comorbid anxiety-depression. CONCLUSIONS: These are the first population-based estimates to demonstrate an association between hypertension and mental disorders in sub-Saharan Africa. Further investigation is needed into role of traumatic life events in the aetiology of hypertension as well as the temporality of the association between hypertension and mental disorders.
Open Access
The Association between Race and Crohn's Disease Phenotype in the Western Cape Population of South Africa, Defined by the Montreal Classification System
(Public Library of Science, 2014) Basson, Abigail; Swart, Rina; Jordaan, Esme; Mazinu, Mikateko; Watermeyer, Gillian
BACKGROUND: Inter-racial differences in disease characteristics and in the management of Crohn's disease (CD) have been described in African American and Asian subjects, however for the racial groups in South Africa, no such recent literature exists. METHODS: A cross sectional study of all consecutive CD patients seen at 2 large inflammatory bowel disease (IBD) referral centers in the Western Cape, South Africa between September 2011 and January 2013 was performed. Numerous demographic and clinical variables at diagnosis and date of study enrolment were identified using an investigator administered questionnaire as well as clinical examination and patient case notes. Using predefined definitions, disease behavior was stratified as ‘complicated’ or ‘uncomplicated’. RESULTS: One hundred and ninety four CD subjects were identified; 35 (18%) were white, 152 (78%) were Cape Coloured and 7(4%) were black. On multiple logistic regression analysis Cape Coloureds were significantly more likely to develop ‘complicated’ CD (60% vs. 9%, p = 0.023) during the disease course when compared to white subjects. In addition, significantly more white subjects had successfully discontinued cigarette smoking at study enrolment (31% vs. 7% reduction, p = 0.02). No additional inter-racial differences were found. A low proportion of IBD family history was observed among the non-white subjects. CONCLUSIONS: Cape Coloured patients were significantly more likely to develop ‘complicated’ CD over time when compared to whites.
Open Access
Birth spacing and child mortality in Mozambique : evidence from two demographic and health surveys
(2008) Gonçalves Sandra Dzidzai; Moultrie, Tom
This research examines child mortality risk associated with short preceding birth intervals in Mozambique in quinquennial periods between 1978 to 1998 using data from the 1997 and 2003 DHS. A log rate model for piecewise constant rates is applied. The piecewise hazard function assumes a constant hazard rate of child mortality in each 6 month category of the preceding birth interval. The negative binomial regression model is applied to account for the overdispersion present in the Poisson model.
Open Access
Can point-of-care urine LAM strip testing for tuberculosis add value to clinical decision making in hospitalised HIV-infected persons
(Public Library of Science, 2013) Peter, Jonathan G; Theron, Grant; Dheda, Keertan
BACKGROUND: The urine lipoarabinomannan (LAM) strip-test (Determine®-TB) can rapidly rule-in TB in HIV-infected persons with advanced immunosuppression. However, given high rates of empiric treatment amongst hospitalised patients in high-burden settings (∼50%) it is unclear whether LAM can add any value to clinical decision making, or identify a subset of patients with unfavourable outcomes that would otherwise have been missed by empiric treatment. METHODS: 281 HIV-infected hospitalised patients with suspected TB received urine LAM strip testing, and were categorised as definite (culture-positive), probable-, or non-TB. Both the proportion and morbidity of TB cases identified by LAM testing, early empiric treatment (initiated prior to test result availability) and a set of clinical predictors were compared across groups. RESULTS: 187/281 patients had either definite- (n = 116) or probable-TB (n = 71). As a rule-in test for definite and probable-TB, LAM identified a similar proportion of TB cases compared to early empiric treatment (85/187 vs. 93/187, p = 0.4), but a greater proportion than classified by a set of clinical predictors alone (19/187; p<0.001). Thirty-nine of the 187 (21%) LAM-positive patients who had either definite- or probable-TB were missed by early empiric treatment, and of these 25/39 (64%) would also have been missed by smear microscopy. Thus, 25/187 (8%) of definite- or probable-TB patients with otherwise delayed initiation of TB treatment could be detected by the LAM strip test. LAM-positive patients missed by early empiric treatment had a lower median CD4 count (p = 0.008), a higher median illness severity score (p = 0.001) and increased urea levels (p = 0.002) compared to LAM-negative patients given early empiric treatment. CONCLUSIONS: LAM strip testing outperformed TB diagnosis based on clinical criteria but in day-to-day practice identified a similar proportion of patients compared to early empiric treatment. However, compared to empiric treatment, LAM identified a different subset of patients with more advanced immunosuppression and greater disease severity.
Open Access
Characteristics of HIV-1 discordant couples enrolled in a trial of HSV-2 suppression to reduce HIV-1 transmission: the partners study
(Public Library of Science, 2009) Lingappa, Jairam R; Kahle, Erin; Mugo, Nelly; Mujugira, Andrew; Magaret, Amalia; Baeten, Jared; Bukusi, Elizabeth A; Cohen, Craig R; Katabira, Elly; Ronald, Allan
BACKGROUND: The Partners HSV-2/HIV-1 Transmission Study (Partners Study) is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2) suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort. METHODS: HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count ≥250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed. RESULTS: Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the HIV-1 infected partners were women. Couples had cohabitated for a median of 5 years (range 2-9) with 28% reporting unprotected sex in the month prior to enrollment. Among HIV-1 susceptible participants, 86% of women and 59% of men were HSV-2 seropositive. Other laboratory-diagnosed sexually transmitted infections were uncommon (<5%), except for Trichomonas vaginalis in 14% of HIV-1 infected women. Median baseline CD4 count for HIV-1 infected participants was 462cells/mcL and median HIV-1 plasma RNA was 4.2 log 10 copies/mL. After adjusting for age and African region, correlates of HIV-1 RNA level included male gender (+0.24 log 10 copies/mL; p<0.001) and CD4 count (−0.25 and −0.55 log 10 copies/mL for CD4 350-499 and >500 relative to <350, respectively, p<0.001). CONCLUSIONS: The Partners Study successfully enrolled a cohort of 3408 heterosexual HIV-1 serodiscordant couples in Africa at high risk for HIV-1 transmission. Follow-up of this cohort will evaluate the efficacy of acyclovir for HSV-2 suppression in preventing HIV-1 transmission and provide insights into biological and behavioral factors determining heterosexual HIV-1 transmission. Trial Registration ClinicalTrials.gov NCT00194519
Open Access
Child and adult mortality in Zimbabwe, 1980-2005
(2011) Marera, Double-Hugh; Dorrington, Rob
This research applies direct and indirect methods to data from censuses and Demographic and Health Surveys to derive empirical estimates of the level and trends of child and adult mortality in Zimbabwe from 1980 to 2005.
Open Access
Completeness of death registration in Cape Town and its health districts, 1996-2004
(2007) Zinyakatira, Nesbert; Dorrington, Rob
It is important for health planners to have timeous and accurate data on deaths. The Department of Home Affairs is responsible for the registration of deaths and the City of Cape Town has a well-established system of collating the death statistics based on vital registration, but the completeness of the death registration has not been assessed previously. The completeness was assessed for the City of Cape Town by comparing their statistics with an estimate based on data obtained from adult deaths reported in the 2001 census. A second approach assessed the trend in completeness between 1996 and 2004 by identifying three rates of mortality considered to be stable over time (non-lung and non-oesophageal cancers, the 10-14 age group and the 60+ age group) and inspecting to observe whether there was any trend apparent over time. Since deaths in most cases are under reported, and the under reporting usually differs in completeness between children and adults, child deaths from the ASSA model projection assuming that they are more complete were compared with the child deaths from the vital registration between 1996 and 2004 to check for completeness of the child vital registration data in Cape Town and its eight health districts The results show high levels of completeness in the adult deaths for Cape Town as a whole in 2001, around 95 per cent, but varying levels in the health districts. The completeness of reporting of male deaths in Cape Town declines with age, whilst completeness for females is fairly level with respect to age, with similar trends being observed in the health districts. Completeness of child (0 -4) death registration averaged around 60 per cent, about 35 per cent lower than the completeness of adult deaths in Cape Town. Cape Town as a whole and most of its health districts revealed two levels of completeness in the registration of deaths, 1996-1999 and 2001-2004 with 2000 sometimes consistent with the first and sometimes with the second period or different from either period in some of the health districts. In conclusion, the completeness estimates obtained are more rigorous from 2001 onwards suggesting that they can be reliably used to monitor trends in the levels of mortality in the city of Cape Town.
Open Access
Defining a sub-Saharan fertility pattern and a standard for use with the relational Gompertz model
(2009) Van Gijsen, Rienier; Moultrie, Tom
The relational Gompertz model is often used to obtain fertility estimates for sub-Saharan Africa populations. This indirect estimation technique is dependent on a fertility standard - the Booth standard. This standard was developed in 1979 using a selection of 33 Coale-Trussell schedules congruent with high fertility patterns. However, evidence from 61 Demographic and Health Surveys of sub-Saharan countries shows that fertility has decreased to levels that were considered medium fertility at the time the standard was developed. This raises concerns about the continued relevance of the (high fertility) Booth standard. In particular, the standard would appear to consistently underestimate fertility among African women aged 45-49.
Open Access
Density-dependent natal dispersal patterns in a leopard population recovering from over-harvest
(Public Library of Science, 2015) Fattebert, Julien; Balme, Guy; Dickerson, Tristan; Slotow, Rob; Hunter, Luke
Natal dispersal enables population connectivity, gene flow and metapopulation dynamics. In polygynous mammals, dispersal is typically male-biased. Classically, the ‘mate competition’, ‘resource competition’ and ‘resident fitness’ hypotheses predict density-dependent dispersal patterns, while the ‘inbreeding avoidance’ hypothesis posits density-independent dispersal. In a leopard ( Panthera pardus ) population recovering from over-harvest, we investigated the effect of sex, population density and prey biomass, on age of natal dispersal, distance dispersed, probability of emigration and dispersal success. Over an 11-year period, we tracked 35 subadult leopards using VHF and GPS telemetry. Subadult leopards initiated dispersal at 13.6 ± 0.4 months. Age at commencement of dispersal was positively density-dependent. Although males (11.0 ± 2.5 km) generally dispersed further than females (2.7 ± 0.4 km), some males exhibited opportunistic philopatry when the population was below capacity. All 13 females were philopatric, while 12 of 22 males emigrated. Male dispersal distance and emigration probability followed a quadratic relationship with population density, whereas female dispersal distance was inversely density-dependent. Eight of 12 known-fate females and 5 of 12 known-fate male leopards were successful in settling. Dispersal success did not vary with population density, prey biomass, and for males, neither between dispersal strategies (philopatry vs. emigration). Females formed matrilineal kin clusters, supporting the resident fitness hypothesis. Conversely, mate competition appeared the main driver for male leopard dispersal. We demonstrate that dispersal patterns changed over time, i.e. as the leopard population density increased. We conclude that conservation interventions that facilitated local demographic recovery in the study area also restored dispersal patterns disrupted by unsustainable harvesting, and that this indirectly improved connectivity among leopard populations over a larger landscape.
Open Access
The determinants of contraceptive use in Zambia
(2011) Fushayi, Nelly; Moultrie, Tom
The contraceptive prevalence rate in Zambia is high, while fertility decline is very slow. From 1992 to 2007, the contraceptive prevalence rate (CPR) increased from 8.9 per cent in 1992 to 32.7 per cent in 2007; while total fertility rate (TFR) fluctuated between 6.5 and 6.2. The study uses three Zambian Demographic and Health Survey (DHS) data sets for 1996, 2001-2 and 2007 and applies multivariate logistic regression techniques to identify factors affecting the use and choice of modern contraceptives by Zambian women. The study seeks to identify how contraceptive use in Zambia influences fertility and why both contraceptive use and fertility are high. In our results, place of residence (urban/rural), age, education, number of living children and formal employment were identified as factors that are significantly related to use of modern contraceptives.
Open Access
The effect of HIV on the orphanhood method of estimating adult female mortality
(2009) Kramer, Stephen; Dorrington, Rob
The orphanhood method of estimating adult mortality is widely used in developing countries. The method is subject to a number of assumptions, some of which are violated when a generalized high-prevalence HIV epidemic is present. Non-independence of the mortality of children and mothers, relationships between HIV infection and fertility, and changes in age-specific mortality result in biases that affect the accuracy of the method. An earlier study has examined some of these sources of error, and proposed adjustments to enable continued use of the method. This earlier research, however, uses data from populations with lower HIV prevalence rates than are currently being experienced in much of southern Africa, and is based on specific assumptions about HIV and its effects on mortality and fertility. The effects of HIV on the method are investigated in this research using mathematical modelling of the effects on Black South African females - a population with high HIV prevalence. More is now known about HIV and its effects on mortality and fertility, and these effects are explicitly reflected in the ASSA2002 model which provides much of the data for this research. The research compares the simulated survival of various cohorts of women: those aged 25 in a certain year, women (with an age profile identical to that of mothers), mothers, and mothers as reported by their children. In this way the various sources of error are explicitly identified and the errors quantified. The timing, magnitude, and combined effects of the errors are studied in relation to the emergence and spread of HIV, indicating when the errors might be expected to be large enough to invalidate the method. Errors that bias the outcomes of the orphanhood method take a number of years to develop after HIV starts spreading. Substantial biases in reported survival emerge between 20 and 35 years after the start of an HIV epidemic, in a high prevalence setting. These errors are reduced by the use of antiretroviral and prevention of mother-to-child transmission, but biases remain large enough to invalidate outcomes when the unadjusted method is applied in most southern African countries. An adjusted method has been proposed which substantially reduces error, except when adjusting survival reported by the two youngest age groups. This adjusted method can be applied, but further research to identify revised adjustments would further improve the accuracy of the method.
Open Access
The effect of HIV/AIDS on the own child-method of estimating child mortality : Lesotho and Zimbabwe
(2011) Musariri, Herbert; Dorrington, Rob
This study evaluates the overall impact of the bias due to HIV/AIDS on the own-child method of estimating child mortality, and the contribution of the various components to the overall bias. Indirect estimates of child mortality are calculated by applying the own-child method to the 2009 Lesotho Demographic and Health Survey (LDHS) and the 2005-6 Zimbabwe DHS. In the process, the potential of the software, MATCHTAB, to link successfully surviving children to their biological mothers is demonstrated using the 2006 Lesotho census data. To evaluate the impact of HIV/AIDS on the own-child method, the target estimates of child mortality for Lesotho and Zimbabwe are also developed by adjusting the direct estimates from the full history data for the selection has introduced by HIV/AIDS.
Open Access
Environmental health hazards on under-five mortality in sub-Saharan Africa : analysis using multilevel discrete-time hazard model
(2014) Engdaw, Alehegn Worku; Adjiwanou, Vissého
Environmental health hazards are pathogens and chemicals in the environment, which can cause health problems. The importance of such environmental factors in child health and survival are acknowledged in the literature. However, empirical researches on the effect of environmental health hazards on child health and survival are rare in sub- Saharan Africa. This study assesses the effect of household environmental health hazards on under-five mortality in sub-Saharan Africa. The study has used DHS data sets of the following 12 countries in the region: Burkina Faso, Burundi, Cameroon, Cote d’Ivoire, Ethiopia, Gabon, Guinea, Malawi, Niger, Rwanda, Senegal and Zimbabwe. These countries constitute roughly 26 per cent of the region’s population. The study has employed principal component method to construct an index of the level of household environmental health hazards using the following indicators: water source, type of toilet facility, flooring material, type of wall, type of roof, type of cooking fuel and location of water source. I have used a multilevel discrete-time hazard model to assess the relationship between the environmental index and under-five mortality after controlling for the effects of a number of socioeconomic, biodemographic and community-level characteristics.
Open Access
Estimating adult mortality in South Africa using orphanhood and year of death data from the 2008 National Income Dynamics Study
(2010) Kupamupindi, Takura; Dorrington, Rob
The overall objective of this research is to investigate whether using year of death data to produce estimates of time location is a better approach than the method developed by Brass and Bamgboye (1981) and whether estimates of mortality produced using year of death data are any better than those derived using the conventional orphanhood method.