Faculty of Health Sciences
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Item CD4+ T-cell count at antiretroviral therapy initiation in the "Treat AII" era in South A: an interrupted time series analysis.(2012-11-05) Yapa HM; Kim H-y; Post FA; Jiamsakul A; de Neve J-W; Tanser F; Iwuji C; Baisley K; Shamanesh M; Pillay D; Siedner MJ; Barnighausen T; Bot JItem Estimates of HIV incidence among drug users in St. Petersburg, Russia: continued growth of a rapidly expanding epidemic(2010-07-30) Linda M. Niccolai; Sergei V. Verevochkin; Olga V. Toussova; Edward White; Russell Barbour; Andrei P. Kozlov; Robert HeimerBackground: Russia has one of the world’s fastest growing HIV epidemics and it has been largely concentrated among injection drug users (IDU). St Petersburg, Russia’s second largest city, is one of the country’s regions that has been most affected by the HIV epidemic. To monitor the current epidemic situation, we sought to estimate recent HIV incidence among IDU in St Petersburg. Methods: In a cross-sectional study of 691 IDU recruited during 2005–08, HIV incidence was estimated by two methods: a retrospective cohort analysis and BED capture enzyme immunoassay (EIA) results. Socio-demographic and behavioural correlates of incident infections and spatial patterns were examined. Results: In the retrospective cohort analysis, the incidence rate was estimated to be 14.1/100 person-years [95% confidence interval (CI) 10.7–17.6]. Using results of BED EIA and two correction formulas for known misclassification, incidence estimates were 23.9 (95% CI 17.8–30.1) and 25.5 (95% CI 18.9–32.0) per 100 person-years. Independent correlates of being recently infected included current unemployment (P = 0.004) and not having injected drugs in the past 30 days (P = 0.03). HIV incident cases were detected in all but one district in the city, with focal areas of transmission observed to be expanding. Conclusions: High HIV incidence among IDU in St Petersburg attests to continued growth of the epidemic. The need for expansion of HIV prevention interventions targeted to vulnerable populations throughout the city is urgent. These results also suggest that the BED EIA may over-estimate incidence even after correction for low specificity.Item Performance of four computer-coded verbal autopsy methods for cause of death assignment compared with physician coding on 24,000 deaths in low- and middle-income countries(2014) Nikita Desai; Lukasz Aleksandrowicz; Pierre Miasnikof; Ying Lu; Jordana Leitao; Peter Byass; Stephen Tollman; Paul Mee; Dewan Alam; Suresh Kumar Rathi; Abhishek Singh; Rajesh Kumar; Faujdar Ram; Prabhat JhaBackground: Physician-coded verbal autopsy (PCVA) is the most widely used method to determine causes of death (CODs) in countries where medical certification of death is uncommon. Computer-coded verbal autopsy (CCVA) methods have been proposed as a faster and cheaper alternative to PCVA, though they have not been widely compared to PCVA or to each other. Methods: We compared the performance of open-source random forest, open-source tariff method, InterVA-4, and the King-Lu method to PCVA on five datasets comprising over 24,000 verbal autopsies from low- and middle-income countries. Metrics to assess performance were positive predictive value and partial chance-corrected concordance at the individual level, and cause-specific mortality fraction accuracy and cause-specific mortality fraction error at the population level. Results: The positive predictive value for the most probable COD predicted by the four CCVA methods averaged about 43% to 44% across the datasets. The average positive predictive value improved for the top three most probable CODs, with greater improvements for open-source random forest (69%) and open-source tariff method (68%) than for InterVA-4 (62%). The average partial chance-corrected concordance for the most probable COD predicted by the open-source random forest, open-source tariff method and InterVA-4 were 41%, 40% and 41%, respectively, with better results for the top three most probable CODs. Performance generally improved with larger datasets. At the population level, the King-Lu method had the highest average cause-specific mortality fraction accuracy across all five datasets (91%), followed by InterVA-4 (72% across three datasets), open-source random forest (71%) and open-source tariff method (54%). Conclusions: On an individual level, no single method was able to replicate the physician assignment of COD more than about half the time. At the population level, the King-Lu method was the best method to estimate cause-specific mortality fractions, though it does not assign individual CODs. Future testing should focus on combining different computer-coded verbal autopsy tools, paired with PCVA strengths. This includes using open-source tools applied to larger and varied datasets (especially those including a random sample of deaths drawn from the population), so as to establish the performance for age- and sex-specific CODsItem Predictors of health care use by adults 50 years and over in a rural South African setting(2014) Ameh, S; Kahn, K; Tollman, S.M; et alBACKGROUND: South Africa's epidemiological transition is characterised by an increasing burden of chronic communicable and non-communicable diseases. However, little is known about predictors of health care use (HCU) for the prevention and control of chronic diseases among older adults. OBJECTIVE: To describe reported health problems and determine predictors of HCU by adults aged 50+ living in a rural sub-district of South Africa. DESIGN: A cross-sectional study to measure HCU was conducted in 2010 in the Agincourt sub-district of Mpumalanga Province, an area underpinned by a robust health and demographic surveillance system. HCU, socio-demographic variables, reception of social grants, and type of medical aid were measured, and compared between responders who used health care services with those who did not. Predictors of HCU were determined by binary logistic regression adjusted for socio-demographic variables. RESULTS: Seventy-five percent of the eligible adults aged 50+ responded to the survey. Average age of the targeted 7,870 older adults was 66 years (95% CI: 65.3, 65.8), and there were more women than men (70% vs. 30%, p<0.001). All 5,795 responders reported health problems, of which 96% used health care, predominantly at public health facilities (82%). Reported health problems were: chronic non-communicable diseases (41% - e.g. hypertension), acute conditions (27% - e.g. flu and fever), other conditions (26% - e.g. musculoskeletal pain), chronic communicable diseases (3% - e.g. HIV and TB), and injuries (3%). In multivariate logistic regression, responders with chronic communicable disease (OR=5.91, 95% CI: 1.44, 24.32) and non-communicable disease (OR=2.85, 95% CI: 1.96, 4.14) had significantly higher odds of using health care compared with those with acute conditions. Responders with six or more years of education had a two-fold increased odds of using health care (OR=2.49, 95% CI: 1.27, 4.86) compared with those with no formal education. CONCLUSION: Chronic communicable and non-communicable diseases were the most prevalent and main predictors of HCU in this population, suggesting prioritisation of public health care services for chronic diseases among older people in this rural setting.Item Barriers to accessing health care in Nigeria: implications for child survival(2014) Adedini, S A; Odimegwu, C; Bamiwuye, S A; et alBackground: Existing studies indicate that about one in every six children dies before age five in Nigeria. While evidence suggests that improved access to adequate health care holds great potential for improved child survival, previous studies indicate that there are substantial barriers to accessing health care in Nigeria. There has not been a systematic attempt to examine the effects of barriers to health care on under-five mortality in Nigeria. This study is designed to address this knowledge gap. Data and method: Data came from a nationally representative sample of 18,028 women (aged 15 49) who had a total of 28,647 live births within the 5 years preceding the 2008 Nigeria Demographic and Health Survey. The risk of death in children below age five was estimated using Cox proportional hazard models and results are presented as hazards ratios (HR) with 95% confidence intervals (CI). Results: Results indicate higher under-five mortality risks for children whose mothers had cultural barriers and children whose mothers had resource-related barriers to health care (HR: 1.44, CI: 1.32 1.57, pB0.001), and those whose mothers had physical barriers (HR: 1.13, CI: 1.04 1.24, pB0.001), relative to children whose mothers reported no barriers. Barriers to health care remained an important predictor of child survival even after adjusting for the effects of possible confounders. Conclusion: Findings of this study stressed the need for improved access to adequate health care in Nigeria through the elimination of barriers to access. This would enable the country to achieve a significant reduction in childhood mortality.Item Factors influencing agency nursing and moonlighting among nurses in South Africa(2014) Rispel, L.C; Blaauw, D; Chirwa, T; et alBACKGROUND: In South Africa, nurses are the largest category of the health care providers. Their optimal performance is critical for the successful implementation of impending health sector reforms. OBJECTIVE: This paper examines the occurrence of agency nursing, moonlighting, and overtime among nurses in South Africa, and the factors influencing moonlighting. DESIGN: This cross-sectional survey was a one-stage cluster random sample of 80 hospitals in four South African provinces, selected with stratification from the public and private health sectors. On the survey day, all nurses working in critical care, theatre, emergency, maternity, and general medical and surgical wards completed a self-administered questionnaire after giving informed consent. In addition to demographic information, the questionnaire elicited information on the frequency of agency nursing, moonlighting, and overtime, and the nurses' reasons for doing moonlighting. Survey data were weighted and analysed using STATA version 12. RESULTS: The majority of survey participants (n = 3,784) were South African (98.0%), female (92.7%), and employed in government (52.8%). Their mean age was 41.5 years (SD 10.4). The occurrence of moonlighting among nurses in the 12 months preceding the survey was 28.0% [95% CI: 24.2-32.1], the frequency of agency nursing was 37.8% [95% CI: 32.4-43.6], while 56.0% of nurses did overtime [95% CI: 51.4-60.4]. In the multiple logistic regression analysis, predictors of moonlighting were province, sector of primary employment, unit of work, category of nurse, and having children. The odds of moonlighting was 1.51 [95% CI: 1.03-2.21] times higher for private sector nurses than for public nurses, while the odds ratio for auxiliary nurses was 0.61 [95% CI: 0.47-0.79] compared to professional nurses. The odds of moonlighting was 1.49 [95% CI: 1.18-1.89] for nurses with children, compared to those without. CONCLUSIONS: Agency nursing, moonlighting, and overtime are common among South African nurses, but have received insufficient policy attention. These issues need to be addressed as part of the implementation of comprehensive health workforce strategies.Item Predictors of adherence to screening guidelines for chronic diseases of lifestyle, cancers, and HIV in a health-insured population in South Africa(2014) Adonis, L; Basu, D; Luiz, J; et alBACKGROUND: Adherence to screening guidelines has been widely accepted to reduce morbidity, mortality, and cost outcomes. The aim of this study was to identify predictors of adherence to screening guidelines for chronic diseases of lifestyle (CDL), cancers, and HIV in a health-insured population in South Africa, some of whom voluntarily opt into a wellness program that incentivizes screening. METHOD: A cross-sectional study for the period 2007-2011 was conducted using a random sample of 170,471 health insurance members from a single insurer. Adherence to screening guidelines was calculated from medical claims data. RESULTS: Adherence to screening guidelines ranged from 1.1% for colorectal cancer to 40.9% for cholesterol screening. Members of the wellness program were up to three times more likely to screen for diseases (odds ratio [OR] = 3.2 for HIV screening, confidence interval [CI] = 2.75-3.73). Plan type (full comprehensive plan) was most strongly associated with cholesterol screening (OR = 3.53, CI = 3.27-3.80), and most negatively associated (hospital-only core plan) with cervical cancer screening (OR = 0.44, CI = 0.28-0.70). Gender was a negative predictor for glucose screening (OR = 0.88, CI = 0.82-0.96). Provincial residence was most strongly associated with cervical cancer screening (OR = 1.89, CI = 0.65-5.54). CONCLUSION: Adherence to screening recommendations was <50%. Plan type, gender, provincial residence, and belonging to an incentivized wellness program were associated with disproportionate utilization of screening services, even with equal payment access.Item Risk factors for unplanned and unwanted teenage pregnancies occurring over two years of follow-up among a cohort of young South African women(2014) Christofides, N.J; Jewkes, R.K; Dunkle, K.L; et alBACKGROUND: Although teenage pregnancies in South Africa have declined, the short and longer term health and social consequences are a potential public health concern. This longitudinal study aimed to describe the range of risk and protective factors for incident unwanted and unplanned pregnancies occurring over 2 years of follow-up among a cohort of adolescent women in the Eastern Cape, South Africa. It also investigated the relationship between gender inequality and gender-based violence and subsequent unplanned and unwanted pregnancies among the cohort. OBJECTIVE: Teenage girls, aged 15-18 years (n=19), who were volunteer participants in a cluster randomized controlled trial and who had data from at least one follow-up were included in this analysis. To assess risk and protective factors for incident unwanted or unplanned pregnancies, we constructed multivariate polytomous regression models adjusting for sampling clusters as latent variables. Covariates included age, having a pregnancy prior to baseline, education, time between interviews, study intervention arm, contraceptive use, experience of intimate partner violence, belief that the teenage girl and her boyfriend are mutual main partners, and socioeconomic status. RESULTS: Overall, 174 pregnancies occurred over the 2-year follow-up period. Beliefs about relationship control were not associated with unwanted and unplanned pregnancies, nor were experiences of forced first sex or coerced sex under the age of 15. Hormonal contraception was protective against unplanned pregnancies (OR 0.40; 95% CI 0.21-0.79); however, using condoms was not protective. Physical abuse (OR 1.69; 95% CI 1.05-2.72) was a risk factor for, and having a pregnancy prior to baseline was protective against an unwanted pregnancy (OR 0.25; 95% CI 0.07-0.80). Higher socioeconomic status was protective for both unplanned and unwanted pregnancies (OR 0.69; 95% CI 0.58-0.83 and OR 0.78; 95% CI 0.64-0.96). Believing that the teenage girl and her boyfriend were mutual main partners doubled the odds of reporting both an unplanned and unwanted pregnancy (OR 2.58 95% CI 1.07-6.25, and OR 2.21 95% CI 1.13-4.29). CONCLUSION: Although some of the measures of gender inequity were not associated with unplanned and unwanted pregnancies, there is evidence of the role of both gender power and socioeconomic status. This was evident in teenage girls who experienced physical violence being more likely to have an unwanted pregnancy. Interventions to prevent teenage pregnancies need to be tailored by socioeconomic status because some teenagers may see having a pregnancy as a way to have a more secure future. Interventions that engage with relationship dynamics of teenagers are essential if unwanted and unplanned pregnancies are to be prevented.Item Essential evidence for guiding health system priorities and policies: anticipating epidemiological transition in Africa(2014) Byass, P; De Savigny, D; Lopez, A.D; et alBACKGROUND: Despite indications that infection-related mortality in sub-Saharan Africa may be decreasing and the burden of non-communicable diseases increasing, the overwhelming reality is that health information systems across most of sub-Saharan Africa remain too weak to track epidemiological transition in a meaningful and effective way. PROPOSALS: We propose a minimum dataset as the basis of a functional health information system in countries where health information is lacking. This would involve continuous monitoring of cause-specific mortality through routine civil registration, regular documentation of exposure to leading risk factors, and monitoring effective coverage of key preventive and curative interventions in the health sector. Consideration must be given as to how these minimum data requirements can be effectively integrated within national health information systems, what methods and tools are needed, and ensuring that ethical and political issues are addressed. A more strategic approach to health information systems in sub-Saharan African countries, along these lines, is essential if epidemiological changes are to be tracked effectively for the benefit of local health planners and policy makers. CONCLUSION: African countries have a unique opportunity to capitalize on modern information and communications technology in order to achieve this. Methodological standards need to be established and political momentum fostered so that the African continent's health status can be reliably tracked. This will greatly strengthen the evidence base for health policies and facilitate the effective delivery of services.Item Does moonlighting influence South African nurses' intention to leave their primary jobs?(2014) Rispel, L; Chirwa, T; Blaauw, D; et alBACKGROUND: Staff retention and turnover have risen in prominence in the global discourse on the health workforce. Moonlighting, having a second job in addition to a primary job, has not featured in debates on turnover. OBJECTIVE: This paper examines whether moonlighting is a determinant of South African nurses' intention to leave their primary jobs. DESIGN: During 2010, a one-stage cluster random sample of 80 hospitals was selected in four South African provinces. On the survey day, all nurses working in critical care, theatre, emergency, maternity, and general medical and surgical wards completed a self-administered questionnaire after giving informed consent. In addition to demographic information and information on moonlighting, the questionnaire obtained information on the participants' intention to leave their primary jobs in the 12 months following the survey. A weighted analysis of the survey data was done using STATA(®) 13. RESULTS: Survey participants (n=3,784) were predominantly middle-aged with a mean age of 41.5 (SD±10.4) years. Almost one-third of survey participants (30.9%) indicated that they planned to leave their jobs within 12 months. Intention to leave was higher among the moonlighters (39.5%) compared to non-moonlighters (27.9%; p<0.001). Predictors of intention to leave in a multiple logistic regression were moonlighting in the preceding year, nursing category, sector of primary employment, period working at the primary job, and number of children. The odds of intention to leave was 1.40 (95% CI: 1.16-1.69) times higher for moonlighters than for non-moonlighters. The odds ratio of intention to leave was 0.53 (95% CI: 0.42-0.66) for nursing assistants compared to professional nurses and 2.09 (95% CI: 1.49-2.94) for nurses working for a commercial nursing agency compared to those working in the public sector.