418 research outputs found

    Setting health research priorities using the CHNRI method: VI. Quantitative properties of human collective opinion.

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    INTRODUCTION: Crowdsourcing has become an increasingly important tool to address many problems - from government elections in democracies, stock market prices, to modern online tools such as TripAdvisor or Internet Movie Database (IMDB). The CHNRI method (the acronym for the Child Health and Nutrition Research Initiative) for setting health research priorities has crowdsourcing as the major component, which it uses to generate, assess and prioritize between many competing health research ideas. METHODS: We conducted a series of analyses using data from a group of 91 scorers to explore the quantitative properties of their collective opinion. We were interested in the stability of their collective opinion as the sample size increases from 15 to 90. From a pool of 91 scorers who took part in a previous CHNRI exercise, we used sampling with replacement to generate multiple random samples of different size. First, for each sample generated, we identified the top 20 ranked research ideas, among 205 that were proposed and scored, and calculated the concordance with the ranking generated by the 91 original scorers. Second, we used rank correlation coefficients to compare the ranks assigned to all 205 proposed research ideas when samples of different size are used. We also analysed the original pool of 91 scorers to to look for evidence of scoring variations based on scorers' characteristics. RESULTS: The sample sizes investigated ranged from 15 to 90. The concordance for the top 20 scored research ideas increased with sample sizes up to about 55 experts. At this point, the median level of concordance stabilized at 15/20 top ranked questions (75%), with the interquartile range also generally stable (14-16). There was little further increase in overlap when the sample size increased from 55 to 90. When analysing the ranking of all 205 ideas, the rank correlation coefficient increased as the sample size increased, with a median correlation of 0.95 reached at the sample size of 45 experts (median of the rank correlation coefficient = 0.95; IQR 0.94-0.96). CONCLUSIONS: Our analyses suggest that the collective opinion of an expert group on a large number of research ideas, expressed through categorical variables (Yes/No/Not Sure/Don't know), stabilises relatively quickly in terms of identifying the ideas that have most support. In the exercise we found a high degree of reproducibility of the identified research priorities was achieved with as few as 45-55 experts

    Phacoemulsification compared with phacotrabeculectomy surgery: a within-person observational cohort study.

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    AIM: To compare reduction in intraocular pressure (IOP) and gain in visual acuity (VA) following phacotrabeculectomy (PT) and phacoemulsification(phaco) in Tanzanian patients with primary open angle glaucoma(POAG). SETTING: CCBRT Hospital, Dar es Salaam, Tanzania. DESIGN: Within-person observational cohort study. METHODS: Within each patient, one eye had PT and the other phaco. Patients were followed for up to 5-1/2 years, and IOP and VA in each eye were assessed. For a small group of patients, two additional postoperative time points were compared. RESULTS: 52 patients (34 male) with a mean age of 70 years (SD 8 years) were enrolled in the study. For those with 250 days or more follow-up, both operations resulted in lower IOPs and improved VA (p<0.001). The average drop in IOP was 50% (95%CI 45% to 55%) for PT and 41% (95% CI 36% to 46%) for phaco. Mean IOP was lower in the PT group 12.9 mm Hg vs 16.8 mm Hg (p=0.004). Extended follow-up in nine patients showed a rise in IOP of 1.8 mm Hg for PT and 4.2 mm Hg for phaco eyes between first (mean, 337 days) and second (mean 1482 days) follow-up (p=0.18). CONCLUSION: In this small study in African patients, PT resulted in lower IOPs than phacoemulsification alone but the difference between the procedures was relatively small. Phacoemulsification alone was effective in reducing IOP and improving VA for several years in this population. Given the relative simplicity of phacoemulsification, it is a therapeutic option worthy of consideration in some settings

    Methods for the analysis of incidence rates in cluster randomized trials.

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    BACKGROUND: The published literature on cluster randomized trials focuses on outcomes that are either continuous or binary. In many trials, the outcome is an incidence rate, such as mortality, based on person-years data. In this paper we review methods for the analysis of such data in cluster randomized trials and present some simple approaches. METHODS: We discuss the choice of the measure of intervention effect and present methods for confidence interval estimation and hypothesis testing which are conceptually simple and easy to perform using standard statistical software. The method proposed for hypothesis testing applies a t-test to cluster observations. To control confounding, a Poisson regression model is fitted to the data incorporating all covariates except intervention status, and the analysis is carried out on the residuals from this model. The methods are presented for unpaired data, and extensions to paired or stratified clusters are outlined. RESULTS: The methods are evaluated by simulation and illustrated by application to data from a trial of the effect of insecticide-impregnated bednets on child mortality. CONCLUSIONS: The techniques provide a straightforward approach to the analysis of incidence rates in cluster randomized trials. Both the unadjusted analysis and the analysis adjusting for confounders are shown to be robust, even for very small numbers of clusters, in situations that are likely to arise in randomized trials

    Estimation of daily risk of neonatal death, including the day of birth, in 186 countries in 2013: a vital-registration and modelling-based study

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    Background The days immediately after birth are the most risky for human survival, yet neonatal mortality risks are generally not reported by day. Early neonatal deaths are sometimes under-reported or might be misclassifi ed by day of death or as stillbirths. We modelled daily neonatal mortality risk and estimated the proportion of deaths on the day of birth and in week 1 for 186 countries in 2013. Methods We reviewed data from vital registration (VR) and demographic and health surveys for information on the timing of neonatal deaths. For countries with high-quality VR we used the data as reported. For countries without high-quality VR data, we applied an exponential model to data from 206 surveys in 79 countries (n=50 396 deaths) to estimate the proportions of neonatal deaths per day and used bootstrap sampling to develop uncertainty estimates. Findings 57 countries (n=122 757 deaths) had high-quality VR, and modelled data were used for 129 countries. The proportion of deaths on the day of birth (day 0) and within week 1 varied little by neonatal mortality rate, income, or region. 1·00 million (36.3%) of all neonatal deaths occurred on day 0 (uncertainty range 0·94 million to 1·05 million), and 2·02 million (73.2%) in the fi rst week (uncertainty range 1·99 million to 2·05 million). Sub-Saharan Africa had the highest risk of neonatal death and, therefore, had the highest risk of death on day 0 (11·2 per 1000 livebirths); the highest number of deaths on day 0 was seen in southern Asia (n=392 300). Interpretation The risk of early neonatal death is very high across a range of countries and contexts. Cost-eff ective and feasible interventions to improve neonatal and maternity care could save many lives

    Predicting quality and quantity of water used by urban households based on tap water service

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    AbstractDespite significant progress in improving access to safe water globally, inadequate access remains a major public health concern in low- and middle-income countries. We collected data on the bacterial quality of stored drinking water and the quantity of water used domestically from 416 households in Uvira, Democratic Republic of the Congo. An indicator of tap water availability was constructed using invoices from 3685 georeferenced piped water connections. We examined how well this indicator predicts the probability that a household’s stored drinking water is contaminated with Escherichia coli, and the total amount of water used at home daily, accounting for distance from alternative surface water sources. Probability of drinking water contamination is predicted with good discrimination overall, and very good discrimination for poorer households. More than 80% of the households are predicted to store contaminated drinking water in areas closest to the rivers and with the worst tap water service, where river water is also the most likely reported source of drinking water. A model including household composition predicts nearly two-thirds of the variability in the reported quantity of water used daily at home. Households located near surface water and with a poor tap water service indicator are more likely to use water directly at the source. Our results provide valuable information that supports an ongoing large-scale investment in water supply infrastructure in Uvira designed to reduce the high burden of cholera and other diarrhoeal diseases. This approach may be useful in other urban settings with limited water supply access.</jats:p

    The influence of distance and level of care on delivery place in rural Zambia: a study of linked national data in a geographic information system.

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    BACKGROUND: Maternal and perinatal mortality could be reduced if all women delivered in settings where skilled attendants could provide emergency obstetric care (EmOC) if complications arise. Research on determinants of skilled attendance at delivery has focussed on household and individual factors, neglecting the influence of the health service environment, in part due to a lack of suitable data. The aim of this study was to quantify the effects of distance to care and level of care on women's use of health facilities for delivery in rural Zambia, and to compare their population impact to that of other important determinants. METHODS AND FINDINGS: Using a geographic information system (GIS), we linked national household data from the Zambian Demographic and Health Survey 2007 with national facility data from the Zambian Health Facility Census 2005 and calculated straight-line distances. Health facilities were classified by whether they provided comprehensive EmOC (CEmOC), basic EmOC (BEmOC), or limited or substandard services. Multivariable multilevel logistic regression analyses were performed to investigate the influence of distance to care and level of care on place of delivery (facility or home) for 3,682 rural births, controlling for a wide range of confounders. Only a third of rural Zambian births occurred at a health facility, and half of all births were to mothers living more than 25 km from a facility of BEmOC standard or better. As distance to the closest health facility doubled, the odds of facility delivery decreased by 29% (95% CI, 14%-40%). Independently, each step increase in level of care led to 26% higher odds of facility delivery (95% CI, 7%-48%). The population impact of poor geographic access to EmOC was at least of similar magnitude as that of low maternal education, household poverty, or lack of female autonomy. CONCLUSIONS: Lack of geographic access to emergency obstetric care is a key factor explaining why most rural deliveries in Zambia still occur at home without skilled care. Addressing geographic and quality barriers is crucial to increase service use and to lower maternal and perinatal mortality. Linking datasets using GIS has great potential for future research and can help overcome the neglect of health system factors in research and policy. Please see later in the article for the Editors' Summary

    Setting health research priorities using the CHNRI method:III. Involving stakeholders

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    Setting health research priorities is a complex and value–driven process. The introduction of the Child Health and Nutrition Research Initiative (CHNRI) method has made the process of setting research priorities more transparent and inclusive, but much of the process remains in the hands of funders and researchers, as described in the previous two papers in this series. However, the value systems of numerous other important stakeholders, particularly those on the receiving end of health research products, are very rarely addressed in any process of priority setting. Inclusion of a larger and more diverse group of stakeholders in the process would result in a better reflection of the system of values of the broader community, resulting in recommendations that are more legitimate and acceptable

    The effect of community health worker-led education on women's health and treatment-seeking: A cluster randomised trial and nested process evaluation in Gujarat, India.

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    BACKGROUND: A community-based health insurance scheme operated by the Self-Employed Women's Association in Gujarat, India reported that the leading reasons for inpatient hospitalisation claims by its members were diarrhoea, fever and hysterectomy - the latter at the average age of 37. This claims pattern raised concern regarding potentially unnecessary hospitalisation amongst low-income women. METHODS: A cluster randomised trial and mixed methods process evaluation were designed to evaluate whether and how a community health worker-led education intervention amongst insured and uninsured adult women could reduce insurance claims, as well as hospitalisation and morbidity, related to diarrhoea, fever and hysterectomy. The 18-month intervention consisted of health workers providing preventive care information to women in a group setting in 14 randomly selected clusters, while health workers continued with regular activities in 14 comparison clusters. Claims data were collected from an administrative database, and four household surveys were conducted amongst a cohort of 1934 randomly selected adult women. RESULTS: 30% of insured women and 18% of uninsured women reported attending sessions. There was no evidence of an intervention effect on the primary outcome, insurance claims (risk ratio (RR) = 1.03; 95% confidence interval (CI) 0.81, 1.30) or secondary outcomes amongst insured and uninsured women, hospitalisation (RR = 1.05; 95% CI 0.58, 1.90) and morbidity (RR = 1.09; 95% CI 0.87, 1.38) related to the three conditions. The process evaluation suggested that participants retained knowledge from the sessions, but barriers to behaviour change were not overcome. CONCLUSIONS: We detected no evidence of an effect of this health worker-led intervention to decrease claims, hospitalisation and morbidity related to diarrhoea, fever and hysterectomy. Strategies that capitalise on health workers' role in the community and knowledge, as well as those that address the social determinants of diarrhoea, fever and the frequency of hysterectomy - such as water and sanitation infrastructure and access to primary gynaecological care - emerged as areas to strengthen future interventions

    Is Beta Radiation Better than 5 Flurouracil as an Adjunct for Trabeculectomy Surgery When Combined with Cataract Surgery? A Randomised Controlled Trial

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    In an African setting surgery is generally accepted as the treatment of first choice for glaucoma. A problem with trabeculectomy surgery for the glaucomas is the frequent co-existence and exacerbation of cataract. We report a randomized controlled trial to compare the use of beta radiation with 5FU in combined cataract and glaucoma surgery. Consenting adults aged >40 years with glaucoma, an IOP>21mmHG and cataract were enrolled and randomised to receive either 1000cG β radiation application or sub-conjunctival 5fluorouracil (5FU) at the time of combined trabeculectomy and phaco-emulsification with lens implant surgery. 385 individuals were eligible for inclusion of whom 301 consented to inclusion in the study (one eye per patient). 150 were randomised to the 5FU arm and 151 received β radiation. In the 12 months following surgery there were 40 failures (IOP>21mmHg) in the 5FU arm and 34 failures in the beta arm. The hazard ratio for the beta radiation arm compared to the 5FU arm, adjusted for IOP at baseline, was 0.83 (95% c.i. 0.54 to 1.28; P = 0.40). The improvement from mean presenting visual acuities of 0.91 and 0.86 logMAR to 0.62 and 0.54 in the 5FU and beta arms respectively was comparable between groups (P = 0.4 adjusting for baseline VA). Incidence of complications did not differ between the two groups. This study highlights several important issues in the quest for a therapeutic strategy for the glaucomas in an African context. Firstly, there is no evidence of an important difference between the use of 5FU and beta radiation as an anti-metabolite in phacotrabeculectomy. Secondly phacotrabeculectomy is a successful operation that improves visual acuity as well as controlling IOP in a majority of patients. Although the success of trabeculectomy in lowering IOP is reduced when combined with phacoemulsification compared with trabeculectomy alone, this finding has to be set against the possible need for subsequent cataract surgery following trabeculectomy alone, which represents a second trip and expense for the patient and results in 10-61% failure of the trabeculectomy at one year post-cataract surgery
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