1,721,147 research outputs found
New approaches to spatially analyse primary health care usage patterns in rural South Africa.
No full textOBJECTIVE: To develop indices to quantitatively assess and understand the spatial usage patterns of health facilities in the Hlabisa district of South Africa. METHODOLOGY: We mapped and interviewed more than 23 000 homesteads (approximately 200 000 people) in Hlabisa district, South Africa and spatially analysed their modal primary health usage patterns using a geographical information system. We generated contour maps of health service use and quantified the relationship between clinic catchments and distance-defined catchments using inclusion and exclusion error. We propose the distance usage index (DUI) as an overall spatial measure of clinic usage. This index is the sum of the distances from clinic to all client homesteads divided by the sum of the distances from clinic to all homesteads within its distance-defined catchment. The index encompasses inclusion, exclusion, and strength of patient attraction for each clinic. RESULTS: Eighty-seven per cent of homesteads use the nearest clinic. Residents of homesteads travel an average Euclidean distance of 4.72 km to attend clinics. There is a significant logarithmic relationship between distance from clinic and their use by homesteads (r(2)=0.774, P < 0.0001). The DUI values range between 31 and 198% (mean=110%, SD=43.7) for 12 clinics and highlight clinic usage patterns across the district. CONCLUSIONS: The DUI is a powerful and informative composite measure of clinic usage. The results of the study have important implications for health care provision in developing countries
Sexual behaviour in a rural high HIV prevalence South African community: time trends in the antiretroviral treatment era
Full text linkObjectives: Data from generalized epidemic settings have consistently found that patients on antiretroviral therapy (ART) reduce sexual risk behaviours, but how sexual behaviour changes in the general population in response to ART availability, including amongst HIV-uninfected and undiagnosed adults, has not been characterized in these settings.Design: General population open cohort.Methods: We report trends in sexual behaviour indicators for men aged 17–54 years and women aged 17–49 years in rural KwaZulu-Natal province, based on annual sexual behaviour surveys during ART scale-up from 2005 to 2011. Estimates are adjusted for survey nonparticipation and nonresponse to individual survey items using inverse probability weighting and multiple imputation. Trends are presented by HIV status, knowledge of status, age and marital status.Results: Reports of condom use at last sex with a regular partner increased by 2.6% points per year [95% confidence interval (CI) 1.5%, 3.7%] for men and 4.1% per year (3.0%, 5.3%) for women. Condom use at last sex with a casual partner was high and did not change significantly over the period for both sexes. There were statistically significant declines in the percentage reporting multiple partnerships in the last year and the point prevalence of concurrency. Trends within subgroups were generally consistent with overall estimates.Conclusion: We find no evidence of increased sexual risk-taking following ART availability and protective changes in some behaviours, suggesting that general trends in sexual behaviour are not counter-acting preventive effects of HIV treatment. Continued monitoring of population-level sexual behaviour indicators will be essential to interpret the success of combination-prevention programmes
The effect of childhood measles vaccination on educational attainment: a mother-fixed-effects study in rural South Africa
No full textBACKGROUND: Because measles vaccination prevents acute measles disease and morbidities secondary to measles, such as undernutrition, blindness, and brain damage, the vaccination may also lead to higher educational attainment. However, there has been little evidence to support this hypothesis at the population level. In this study, we estimate the causal effect of childhood measles vaccination on educational attainment among children born between 1995 and 2000 in South Africa.METHODS AND FINDINGS: We use longitudinal data on measles vaccination status and school grade attainment among 4783 children. The data were collected by the Wellcome Trust Africa Centre Demographic Information System (ACDIS), which is one of Africa's largest health and demographic surveillance systems. ACDIS is located in a poor, predominantly rural, Zulu-speaking community in KwaZulu-Natal, South Africa. Using mother fixed-effects regression, we compare the school grade attainment of siblings who are discordant in their measles vaccination status but share the same mother and household. This fixed-effects approach controls for confounding due to both observed and unobserved factors that do not vary between siblings, including sibling-invariant mother and household characteristics such as attitudes toward risk, conscientiousness, and aspirations for children. We further control for a range of potential confounders that vary between siblings, such as sex of the child, year of birth, mother's age at child's birth, and birth order. We find that measles vaccination on average increases school grade attainment by 0.188 grades (95% confidence interval, 0.0424-0.334; p=0.011).CONCLUSIONS: Measles vaccination increased educational attainment in this poor, largely rural community in South Africa. For every five to seven children vaccinated against measles, one additional school grade was gained. The presence of a measles vaccination effect in this community is plausible because (i) measles vaccination prevents measles complications including blindness, brain damage, and undernutrition; (ii) a large number of number of children were at risk of contracting measles because of the comparatively low measles vaccination coverage; and (iii) significant measles transmission occurred in the community where this study took place during the study observation period. Our results demonstrate for the first time that measles vaccination affects human development not only through its health effects but also through its effects on education.<br/
Partner age-disparity and HIV incidence risk for older women in rural South Africa
No full textWhile sexual partner age disparity is frequently considered as a potential risk factor for HIV among young women in Africa, no research has addressed this question among older women. Our aim was thus to determine whether sex partner age disparity was associated with subsequent HIV acquisition in women over 30 years of age. To achieve this aim we conducted a quantitative analysis of a population-based, open cohort of women in rural KwaZulu-Natal, South Africa (n = 1,737) using Cox proportional hazards models. As partner age rose, HIV acquisition risk fell significantly: compared to a same-aged partner, a 5-year older partner was associated with a one-third reduction [hazard ratio (HR) 0.63, 95 % CI 0.52–0.76] and a 10-year older partner with a one-half reduction (HR 0.48, 95 % CI 0.35–0.67) in acquisition risk. This result was neither confounded nor effect-modified by women’s age or socio-demographic factors. These findings suggest that existing HIV risk-reduction campaigns warning young women about partnering with older men may be inappropriate for older women. HIV prevention strategies interventions specifically tailored to older women are neede
Sexual behaviour trends by gender in a rural South African population-based cohort during the era of scaled-up access to VCT and ART, 2005-2010
No full textBackground: In rural KwaZulu-Natal, HIV incidence has been high and changed little even while HIV testing uptake has increased dramatically over the past six years. We examine population-level trends in sexual risk behaviour over the period 2005-2010 in a general-population cohort.Methods: We report trends in sexual behaviour indicators from 2005 to 2010 for men and women aged 17-49, based on annual sexual behaviour surveys collected by the Africa Centre Demographic Information System (ACDIS). Indicators include the proportion ever had sex, the average number of sexual partners in the past year, the point-prevalence of concurrent sexual partnerships, and condom use at last sex with regular and casual partners. Trends are compared between groups defined by HIV status, knowledge of HIV status, and by other population characteristics. Unadjusted trends and trends adjusted for varying survey participation are presented. Missing data in completed surveys is adjusted for using multiple imputation incorporating demographic, socioeconomic, behavioural and health variables from the ACDIS. Responses are weighted by sex/age/education/location strata to adjust for survey non-participation.Results: Reported sexual risk behaviours may have declined in men and women over 2005-2010, but the decline is less pronounced than would have appeared without adjusting for missing data and survey participation. Increases in reported condom usage have been greater than reductions in numbers of sexual partners. For both sexes, reported condom usage with regular partners increases more amongst those who know they are HIV-positive than those who have tested HIV-negative. Conclusions: These population trends in self-reported sexual behaviour suggest that some behaviour change occurred between 2005-2010 in the general population. Changes occurred in both those living with and without HIV, but the data suggest that greater changes occurred in those who reported knowing they were HIV positive. The full presentation will also include results of sub-group analyses
Use of antiretroviral therapy in households and risk of HIV acquisition in rural KwaZulu-Natal, South Africa, 2004-2012: a prospective cohort study
Full text linkBackground: studies of HIV-serodiscordant couples in stable sexual relationships have provided convincing evidence that antiretroviral therapy can prevent the transmission of HIV. We aimed to quantify the preventive effect of a public-sector HIV treatment and care programme based in a community with poor knowledge and disclosure of HIV status, frequent migration, late marriage, and multiple partnerships. Specifically, we assessed whether an individual's hazard of HIV acquisition was associated with antiretroviral therapy coverage among household members of the opposite sex.Methods: in this prospective cohort study, we linked patients' records from a public-sector HIV treatment programme in rural KwaZulu-Natal, South Africa, with population-based HIV surveillance data collected between 2004 and 2012. We used information about coresidence to construct estimates of HIV prevalence and antiretroviral therapy coverage for each household. We then regressed the time to HIV seroconversion for 14?505 individuals, who were HIV-uninfected at baseline and individually followed up over time regarding their HIV status, on opposite-sex household antiretroviral therapy coverage, controlling for household HIV prevalence and a range of other potential confounders.Findings: 2037 individual HIV seroconversions were recorded during 54?845 person-years of follow-up. For each increase of ten percentage points in opposite-sex household antiretroviral therapy coverage, the HIV acquisition hazard was reduced by 6% (95% CI 2–9), after controlling for other factors. This effect size translates into large reductions in HIV acquisition hazards when household antiretroviral therapy coverage is substantially increased. For example, an increase of 50 percentage points in household antiretroviral therapy coverage (eg, from 20% to 70%) reduced the hazard of HIV acquisition by 26% (95% CI 9–39).Interpretation: our findings provide further evidence that antiretroviral therapy significantly reduces the risk of onward transmission of HIV in a real-world setting in sub-Saharan Africa. Awareness that antiretroviral therapy can prevent transmission to coresident sexual partners could be a powerful motivator for HIV testing and antiretroviral treatment uptake, retention, and adherence<br/
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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