919Step-by-step guidance on prospective meta-analyses

Focus of Presentation In a prospective meta-analysis (PMA), studies are included before their results are known. This can reduce risk of publication bias and selective outcome reporting, and enables researchers to harmonise their research efforts. Despite rising numbers, there is little guidance on how to conduct PMA. We, the Cochrane PMA Methods Group, developed step-by-step guidance based on a scoping review, and expert opinions and experiences. Each step is illustrated with a recent case study. Findings We describe seven steps for conducting PMA. After developing a protocol (Steps 1), a systematic search for eligible planned/ongoing studies should be conducted, including a search of registries, medical databases and contacting stakeholders (Step 2-3). These studies are then invited to form a collaboration (Step 4), ideally including a steering and data analysis committee. Next, important study features such as common core outcomes and confounders are agreed upon (Step 5). This reduces heterogeneity and increases the number of available outcomes for meta-analysis. Certainty of evidence is assessed by adapting tools such as GRADE (Step 6). Results should be reported using adapted versions of reporting tools such as PRISMA (Step 7). Conclusions/Implications PMA reduce many problems of traditional retrospective systematic reviews and meta-analysis. Updated guidance and recent technical advances will help increase their numbers further. Key messages PMA are ‘next generation systematic reviews’ that allow for greatly improved use of data, whilst reducing bias and research waste. This step-by-step guidance will enable more researchers to conduct successful PMA.

NGA-East Ground-Motion Characterization model part I: Summary of products and model development

In this article, we present an overview of the research project NGA-East, Next Generation Attenuation for Central and Eastern North America (CENA), and summarize the key methodology and products. The project was tasked with developing a new ground motion characterization (GMC) model for CENA. The final NGA-East GMC model includes a set of 17 median ground motion models (GMMs) for peak ground acceleration and velocity (PGA, PGV) and response spectral ordinates for periods ranging from 0.01 to 10 s. The NGA-East GMMs are applicable to horizontal components of ground motions on very hard rock, for the moment magnitude range of 4.0–8.2, and distances of up to 1500 km. The aleatory standard deviations of GMMs are also provided for site-specific analysis (single-station standard deviation) and for general probabilistic seismic hazard analyses (PSHA) applications (ergodic standard deviation). In addition, adjustment factors are provided for source depth and hanging-wall effects, as well as for hazard computations at sites in the Gulf Coast Region. During the course of the project, several innovative technologies were developed and implemented to increase the transparency and repeatability of the GMC building process. This involved expanding on a set of candidate median GMMs to define and capture an appropriate range of epistemic uncertainty in ground motions. We also developed a new approach for modeling the aleatory variability that was completely independent of the median GMMs. The development made extensive use of the CENA database but also borrowed data from other parts of the world when relevant and led to an integrated suite of models. Through this repeatable process, epistemic uncertainty could be quantified more objectively than before, relying less on expert opinion. The NGA-East project went through a comprehensive Seismic Senior Hazard Analysis Committee (SSHAC) Level 3 peer review process before its release.

Developer contributions and community benefits: understanding the regulatory context for the implementation of a value-capturing instrument in Northern Ireland

Developer contributions have a rich history in all UK jurisdictions, other than in Northern Ireland (NI). This paper presents a moment in NI’s planning modernisation in which a scheme of developer contributions has been introduced, primarily by Belfast City Council. There has been little scholarship devoted to NI’s planning reform, however, there has been considerable attention directed to the increasingly neo-liberal governing landscape in which these reforms took place. We consider this debate and try to place the implementation of developer contributions in this context. Our primary evidence is based on policy analysis, committee records and interviews with stakeholders across the planning community. In the case we have presented the lack of definition around what constitutes a community benefit has opened space for deliberation across the NI planning community. This discussion has encouraged a debate that broadly centres around a neo-liberal abstraction of the purpose of developer contributions. When considering the subject of this special issue, Rethinking Regulation, we question what the purpose is for developer contributions as a contemporary planning process. We do this by investigating the relationship between ‘community’ and the ‘public interest’ under neo-liberal governing regimes. We present issues of policy ambiguity, of scale and of viability as a decision-making tool. We conclude that deverloper contributions in NI have become an instrument that is narrow in purpose, yet one which has become codified around a market-focused rationality. We finally reflect on policy performance to date, highlighting a seemingly inherent difficulty for planning authorities in realising social outcomes through developer contributions.