Meta-analysis is a method to obtain a weighted average of results from various studies. In addition to pooling effect sizes, meta-analysis can also be used to estimate disease frequencies, such as incidence and prevalence. In this article we present methods for the meta-analysis of prevalence. We discuss the logit and double arcsine transformations to stabilise the variance. We note the special situation of multiple category prevalence, and propose solutions to the problems that arise. We describe the implementation of these methods in the MetaXL software, and present a simulation study and the example of multiple sclerosis from the Global Burden of Disease 2010 project. We conclude that the double arcsine transformation is preferred over the logit, and that the MetaXL implementation of multiple category prevalence is an improvement in the methodology of the meta-analysis of prevalence.

Meta-analysis of prevalence

Ash-related issues during biomass combustion: Alkali-induced slagging, silicate melt-induced slagging (ash fusion), agglomeration, corrosion, ash utilization, and related countermeasures

Impact of fly ash incorporation in soil systems.

Fly ash for soil amelioration: A review on the influence of ash blending with inorganic and organic amendments

Coal combustion produces carbon dioxides, SOx, NOx and a variety of byproducts, including fly-ash, flue gas and scrubber sludge Fly-ash consists of minute glass-like particles and its deposition on leaves inhibits the normal transpiration and photosynthesis of plants Fly-ash also affects the physicochemical characteristics of soil because it is generally very basic, rich in various essential and non-essential elements, but poor in both nitrogen and available phosphorus The massive fly-ash materials have been a potential resource for the agricultural activities as well as the other industrial purposes Practical value of fly-ash in agriculture as an 'effective and safe' fertiliser or soil amendment can be established after repeated field experiments Here remains to be disclosed the biological processes and interactions due to 'lack and excess' of the fly-ash exposures along with abiotic and biotic factors These may involve the symbiotic fixation of nitrogen and the biological extraction of metals following immobilisation of toxic heavy metal ions, as well as other neutralisation and equilibration processes during weathering Nitrogen-fixing plants with an apparent heavy metal-tolerance can be helpful as the early colonisers of fly-ash dumps and nearby areas

Impacts of fly-ash on soil and plant responses.

Germination and seedling growth of vegetable crops in fly ash-amended soils

Effects of fly ash on yields and elemental composition of two vegetables, Brassica parachinensis and B. chinensis

Objective: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging global public health threat. In response to a highlighted strategic priority of the World Health Organization Global Action Plan on Antimicrobial Resistance, to “strengthen the knowledge and evidence base through surveillance and research”, we synthesized published articles to estimate CA-MRSA carriage prevalence in the Asia-Pacific region. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO CRD: 42017067399). We searched MEDLINE, EMBASE, and PubMed for articles published from January 1, 2000, to May 19, 2017, that reported CA-MRSA carriage, defined as either colonization or infection, in Asia-Pacific region, from 2000 to 2016. Studies were stratified according to (1) setting (community or hospital where CA-MRSA was isolated) and (2) study population (general public or subpopulations categorized according to specified characteristics). Prevalence of CA-MRSA carriage was estimated using a DerSimonian-Laird random-effects model. Results: A total of 153 studies were identified. In community level studies, the CA-MRSA prevalence among the general public ranged from 0.3% - 23.5% (pooled prevalence:5.0%; 95%CI 2.2, 8.8). The prevalence among the same group in hospital settings ranged from 0% - 10.4% (pooled prevalence: 2.1% 95% CI 0.9, 3.7). The country with the highest community setting prevalence was India, followed by Vietnam and Taiwan. Children 6 years and household members of CA-MRSA carriers had the highest carriage in community settings. Conclusion: The current CA-MRSA prevalence estimates provide a baseline for future national and international surveillance. The pooled prevalence and identification of characteristics associated with CA-MRSA carriage in the community can inform health authorities to formulate specific infection control policies on high-risk subgroups. Future studies should explore the heterogeneities in the prevalence of CA-MRSA carriage among subgroups and countries, in order to clarify the predominant transmission mechanisms in Asia-Pacific and other regions.

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Prevalence and risk factors of community-associated methicillin-resistant Staphylococcus aureus carriage in Asia-Pacific region from 2000 to 2016: a systematic review and meta-analysis.

Jonathan W. C. Wong

Papers

Germination and seedling growth of vegetable crops in fly ash-amended soils

Effects of fly ash on yields and elemental composition of two vegetables, Brassica parachinensis and B. chinensis

Prevalence and risk factors of community-associated methicillin-resistant Staphylococcus aureus carriage in Asia-Pacific region from 2000 to 2016: a systematic review and meta-analysis.