Abstract Objective Meta-analysis of individual patient data (IPD) is the “gold-standard” for synthesizing evidence across several studies. Some studies, however, may only provide aggregate data (AD). ...In this situation researchers might need to combine IPD with AD to utilize all the evidence available. Here, we review applied IPD meta-analysis articles to assess if and how AD is combined with IPD in practice. Study Design and Setting A systematic review of articles identified from bibliographic databases and searches. Results We identified 33 applied IPD articles that combined IPD and AD and 166 that did not. For each article, we recorded the proportion of total studies providing IPD, and found that articles combining IPD and AD had, on average, IPD available in only 64% of studies (compared to 90% in articles not combining IPD and AD). Two different methods were used to combine IPD and AD, the two-stage method and analysis of partially reconstructed IPD, but a review of methodological articles identified two further methods, multilevel modeling and Bayesian hierarchical related regression. We summarize each method to aid practitioners. Conclusion Combining IPD and AD is a relevant issue for evidence synthesis, and the further development and validation of suitable meta-analysis methods is needed.
This letter presents a synthetic L-band (1.4 GHz) multiangular brightness temperature dataset over land surfaces that was simulated at a half-degree resolution and at the global scale. The microwave ...emission of various land-covers (herbaceous and woody vegetation, frozen and unfrozen bare soil, snow, etc.) was computed using a simple model L-band Microwave Emission of the Biosphere (L-MEB) based on radiative transfer equations. The soil and vegetation characteristics needed to initialize the L-MEB model were derived from existing land-cover maps. Continuous simulations from a land-surface scheme for 1987 and 1988 provided time series of the main variables driving the L-MEB model: soil temperature at the surface and at depth, surface soil moisture, proportion of frozen surface soil moisture, and snow cover characteristics. The obtained global maps constitute a useful dataset for a first evaluation of the sensitivity of future satellite-based L-band radiometry data to soil moisture.
Previous studies reported decreased mortality in patients with carbapenemase-producing Klebsiella pneumoniae bloodstream infections (BSIs) treated with combination therapy but included ...carbapenem-susceptible and -intermediate isolates, as per revised CLSI breakpoints. Here, we assessed outcomes in patients with BSIs caused by phenotypically carbapenem-resistant K. pneumoniae (CRKP) according to the number of in vitro active agents received and whether an extended-spectrum beta-lactam (BL) antibiotic, including meropenem, or an extended-spectrum cephalosporin was administered. We retrospectively reviewed CRKP BSIs at two New York City hospitals from 2006 to 2013, where all isolates had meropenem or imipenem MICs of ≥4 μg/ml. Univariate and multivariable models were created to identify factors associated with mortality. Of 141 CRKP BSI episodes, 23% were treated with a single active agent (SAA), 26% were treated with an SAA plus BL, 28% were treated with multiple active agents (MAA), and 23% were treated with MAA plus BL. Ninety percent of isolates had meropenem MICs of ≥16 μg/ml. Thirty-day mortality was 33% overall and did not significantly differ across the four treatment groups in a multivariable model (P = 0.4); mortality was significantly associated with a Pitt bacteremia score of ≥4 (odds ratio OR, 7.7; 95% confidence interval CI, 3.2 to 18.1; P = 0.1), and immunosuppression was protective (OR, 0.4; 95% CI, 0.2 to 1.0; P = 0.04). Individual treatment characteristics were also not significantly associated with outcome, including use of SAAs versus MAA (26% versus 38%, P = 0.1) or BL versus no BL (26% versus 39%, P = 0.1). In summary, in patients with CRKP BSIs caused by isolates with high carbapenem MICs, the role of combination therapy remains unclear, highlighting the need for prospective studies to identify optimal treatment regimens.
National emission inventories of ozone‐depleting substances (ODS) play a key role in the control mechanisms of the Montreal Protocol's emission reduction plans. New quasi‐continuous ground‐based ...atmospheric measurements allow us to estimate China's current emissions of the most effective ODS. This serves as an independent validation of China's ODS consumption data reported to the United Nations Environment Programme (UNEP). Emissions of most first‐generation ODS have declined in recent years, suggesting compliance with the regulations of China's advanced phase‐out program. In contrast the emissions of some second‐generation ODS have increased. Because China is currently one of the largest consumers of first generation ODS, the country's upcoming complete phase‐out will be crucial for the rate of decline of atmospheric ODS hence the eventual recovery of the stratospheric ozone.
Three new tetranortriterpenoids, methyl 6-hydroxy-11 beta-acetoxy-12 alpha-(2-methylpropanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (3), methyl 6,11 beta-dihydroxy-12 ...alpha-(2-methylpropanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (4), and methyl 6-hydroxy-11 beta-acetoxy-12 alpha-(2-methylbutanoyloxy)-3,7-dioxo-14 beta,15 beta-epoxy-1,5-meliacadien-29-oate (5), have been isolated from the roots of Trichilia pallida. The related compounds hirtin (1) and deacetylhirtin (2) were also obtained. Compound 4 had the greatest antifeedant activity of 1-5 when tested against larvae of four species of Lepidoptera.
The effectiveness of surgery for colorectal cancer depends on it being carried out safely, which allows most patients to return to productive lives, with an improved postoperative life expectancy, or ...at least one that is not diminished by the surgery. Because colorectal cancer is a major cause of morbidity and mortality in elderly people, we have examined how the outcomes of surgery in elderly patients differ from those in younger patients.
We did a systematic review of published and aggregate data provided by investigators. Studies were identified by computerised and manual searches of published and unpublished reports, scanning references, and contacting investigators. Within each study, outcomes for patients aged 65–74 years, 75–84 years, and 85+ years were expressed in relation to those aged less than 65 years.
From 28 independent studies, and a total of 34194 patients, we found that elderly patients had an increased frequency of comorbid conditions, were more likely to present with later-stage disease and undergo emergency surgery, and less likely to have curative surgery than younger patients. The incidence of postoperative morbidity and mortality increased progressively with advancing age. Overall survival was reduced in elderly patients, but for cancer specific survival age-related differences were much less striking.
The relation between age and outcomes from colorectal cancer surgery is complex and may be confounded by differences in stage at presentation, tumour site, pre-existing comorbidities, and type of treatment received. However, selected elderly patients benefit from surgery since a large proportion survive for 2 or more years, irrespective of their age.
The ‘sniffing position’ is widely promoted for teaching airway positioning before intubation, but whether this analogy results in novices placing the head and neck appropriately has not been ...evaluated. We compared performance following the sniffing position instructions with an alternate analogy, ‘win with the chin’. We also compared performance following simple anatomic instructions and no instructions.
A randomized controlled study of medical students and PGY1 registrars in Surgery and Internal Medicine was performed. Subjects independently positioned a simulator manikin head and neck based upon their understanding of four written instructions in random order: (i) the ‘sniffing position’; (ii) the ‘win with the chin’ analogy, (iii) anatomic instructions; and (iv) no instructions (control). Digital photographs following each instruction were analysed by two airway experts for (i) adequacy of overall positioning and (ii) the three components of airway positioning.
Eighty-one volunteers participated. The positioning was adequate most often (43.2%) following the ‘win with the chin’ analogy when compared with the other instructions (37.0% anatomic instructions; 19.8% control; 14.8% ‘sniffing position’ analogy). Positioning following the ‘sniffing position’ instructions was not different from no instruction (P=0.53). The ‘win with the chin’ and anatomic instructions were significantly better than no instructions (P=0.002 and 0.023, respectively).
The ‘win with the chin’ analogy resulted in adequate airway positioning significantly more often than the ‘sniffing position’ or control. It also maintained atlanto-occipital extension compared with anatomic instructions. Overall, ‘win with the chin’ was a superior teaching analogy and could replace the ‘sniffing position’ analogy.
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