844 research outputs found
Water and sanitation infrastructure for health: The impact of foreign aid
<p>Abstract</p> <p>Background</p> <p>The accessibility to improved water and sanitation has been understood as a crucial mechanism to save infants and children from the adverse health outcomes associated with diarrheal disease. This knowledge stimulated the worldwide donor community to develop a specific category of aid aimed at the water and sanitation sector. The actual impact of this assistance on increasing population access to improved water and sanitation and reducing child mortality has not been examined.</p> <p>Methods</p> <p>We performed a country-level analysis of the relationship between water and sanitation designated official development assistance (WSS-ODA) per capita, water and sanitation coverage, and infant and child mortality in low-income countries as defined by the World Bank. We focused our inquiry to aid effectiveness since the establishment of the Millennium Development Goals (MDGs).</p> <p>Results</p> <p>Access to improved water has consistently improved since 2002. Countries receiving the most WSS-ODA ranged from odds ratios of 4 to 18 times more likely than countries in the lowest tertile of assistance to achieve greater gains in population access to improved water supply. However, while there were modestly increased odds of sanitation access, these were largely non-significant. The countries with greatest gains in sanitation were 8-9 times more likely to have greater reductions in infant and child mortality.</p> <p>Conclusions</p> <p>Official development assistance is importantly impacting access to safe water, yet access to improved sanitation remains poor. This highlights the need for decision-makers to be more intentional with allocating WSS-ODA towards sanitation projects.</p
Improving the interpretation of quality of life evidence in meta-analyses: the application of minimal important difference units
Systematic reviews of randomized trials that include measurements of health-related quality of life potentially provide critical information for patient and clinicians facing challenging health care decisions. When, as is most often the case, individual randomized trials use different measurement instruments for the same construct (such as physical or emotional function), authors typically report differences between intervention and control in standard deviation units (so-called "standardized mean difference" or "effect size"). This approach has statistical limitations (it is influenced by the heterogeneity of the population) and is non-intuitive for decision makers. We suggest an alternative approach: reporting results in minimal important difference units (the smallest difference patients experience as important). This approach provides a potential solution to both the statistical and interpretational problems of existing methods
Methods to convert continuous outcomes into odds ratios of treatment response and numbers needed to treat: meta-epidemiological study
Background Clinicians find standardized mean differences (SMDs) calculated from continuous outcomes difficult to interpret. Our objective was to determine the performance of methods in converting SMDs or means to odds ratios of treatment response and numbers needed to treat (NNTs) as more intuitive measures of treatment effect. Methods Meta-epidemiological study of large-scale trials (≥100 patients per group) comparing active treatment with placebo, sham or non-intervention control. Trials had to use pain or global symptoms as continuous outcomes and report both the percentage of patients with treatment response and mean pain or symptom scores per group. For each trial, we calculated odds ratios of observed treatment response and NNTs and approximated these estimates from SMDs or means using all five currently available conversion methods by Hasselblad and Hedges (HH), Cox and Snell (CS), Furukawa (FU), Suissa (SU) and Kraemer and Kupfer (KK). We compared observed and approximated values within trials by deriving pooled ratios of odds ratios (RORs) and differences in NNTs. ROR <1 and positive differences in NNTs imply that approximations are more conservative than estimates calculated from observed treatment response. As measures of agreement, we calculated intraclass correlation coefficients. Results A total of 29 trials in 13 654 patients were included. Four out of five methods were suitable (HH, CS, FU, SU), with RORs between 0.92 for SU [95% confidence interval (95% CI), 0.86-0.99] and 0.97 for HH (95% CI, 0.91-1.04) and differences in NNTs between 0.5 (95% CI, −0.1 to −1.6) and 1.3 (95% CI, 0.4-2.1). Intraclass correlation coefficients were ≥0.90 for these four methods, but ≤0.76 for the fifth method by KK (P for differences ≤0.027). Conclusions The methods by HH, CS, FU and SU are suitable to convert summary treatment effects calculated from continuous outcomes into odds ratios of treatment response and NNTs, whereas the method by KK is unsuitabl
People's Values and Preferences about Meat Consumption in View of the Potential Environmental Impacts of Meat : A Mixed-methods Systematic Review
Health is not the only aspect people consider when choosing to consume meat; environmental concerns about the impact of meat (production and distribution) can influence people's meat choices. Methods: We conducted a mixed-methods systematic review, searched six databases from inception to June 2020, and synthesised our findings into narrative forms. We integrated the evidence from quantitative and qualitative data sets into joint displays and assessed the confidence in the evidence for each review finding following the GRADE-CERQual approach. Results: Of the 23,531 initial records, we included 70 studies: 56 quantitative, 12 qualitative, and 2 mixed-methods studies. We identified four main themes: (1) reasons for eating meat; (2) reasons for avoiding meat; (3) willingness to change meat consumption; and (4) willingness to pay more for environmentally friendly meat. The overall confidence was low for the reasons for eating and/or buying meat, for avoiding meat, and for willingness to change meat consumption, and was moderate for willingness to pay more for environmentally friendly meat. Conclusions: Regardless of people's general beliefs about meat and its impact on the environment, most people may be unwilling to change their meat consumption. Future research should address the current limitations of the research evidence to assess whether people are willing to make a change when properly informed
Prevention of Clostridium difficile Infection: A Systematic Survey of Clinical Practice Guidelines
background. Clostridium difficile infection (CDI) is the most common cause of hospital-acquired infectious diarrhea.
objective. To analyze themethodological quality, content, and supporting evidence among clinical practice guidelines (CPGs) on CDI prevention.
design and setting. We searched medical databases and gray literature for CPGs on CDI prevention published January 2004-January
2015. Three reviewers independently screened articles and rated CPG quality using the Appraisal of Guidelines for Research and Evaluation II
(AGREE II) instrument, composed of 23 items, rated 1–7, within 6 domains. We reported each domain score as a percentage of its maximum
possible score and standardized range. We summarized recommendations, extracted their supporting articles, and rated individually the level of
evidence using the Oxford Centre for Evidence-Based Medicine Levels of Evidence.
results. Of 2,578 articles screened, 5 guidelines met inclusion criteria. Median AGREE II scores and interquartile ranges were: clarity of
presentation, 75.9% (75.9%–79.6%); scope and purpose, 74.1% (68.5%–85.2%); editorial independence, 63.9% (47.2%–66.7%); applicability,
43.1% (19.4%–55.6%); stakeholder involvement, 40.7% (38.9%–44.4%); and rigor of development, 18.1% (17.4%–35.4%). CPGs addressed
several common strategies for CDI prevention, including antibiotic stewardship, hypochlorite solutions, probiotic prophylaxis, and bundle
strategies. Recommendations were often not consistent with evidence, and most were based on low-level studies.
conclusion. CPGs did not adhere well to AGREE II reporting standards. Furthermore, there was limited transparency in moving from
evidence to recommendations. CDI prevention CPGs need to better adhere to AGREE-II and be transparent in moving from evidence to
recommendations, and recommendations need to be consistent with available evidence
GRADE guidelines 17:Assessing the risk of bias associated with missing participant outcome data in a body of evidence
Objective: To provide GRADE guidance for assessing risk of bias across an entire body of evidence consequent on missing data for systematic reviews of both binary and continuous outcomes. Study Design and Setting: Systematic survey of published methodological research, iterative discussions, testing in systematic reviews, and feedback from the GRADE Working Group. Results: Approaches begin with a primary meta-analysis using a complete case analysis followed by sensitivity meta-analyses imputing, in each study, data for those with missing data, and then pooling across studies. For binary outcomes, we suggest use of "plausible worst case" in which review authors assume that those with missing data in treatment arms have proportionally higher event rates than those followed successfully. For continuous outcomes, imputed mean values come from other studies within the systematic review and the standard deviation (SD) from the median SDs of the control arms of all studies. Conclusions: If the results of the primary meta-analysis are robust to the most extreme assumptions viewed as plausible, one does not rate down certainty in the evidence for risk of bias due to missing participant outcome data. If the results prove not robust to plausible assumptions, one would rate down certainty in the evidence for risk of bias.</p
Turbulent burning rates of gasoline components, Part 2-Effect of carbon number
Experimental measurements of turbulent and laminar burning velocities have been made for premixed hydrocarbon–air flames of straight chain molecules of increasing carbon number (from n-pentane to n-octane). Measurements were performed at 0.5 MPa, 360 K and rms turbulent velocities of 2 and 6 m/s, for a range of equivalence ratios. The laminar burning velocities were used to interpret the turbulent data, but were also found to be broadly in line with those of previous workers. At lean conditions the turbulent burning velocity was measured to be similar between the four alkanes studied. However, at rich conditions there were notable differences between the turbulent burn rates of the fuels. The equivalence ratio of the mixtures at which the maximum burning velocities occurred in the turbulent flames was richer than that under laminar conditions. The equivalence ratio of the peak turbulent burning velocity was found to be a function of the carbon number of the fuel and the turbulent intensity and became gradually fuel rich with increases in each of these values
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