COMMENT © 2 0 1 7 M a c m i l l a n P u b l i s h e r s L i m i t e d , p a r t o f S p r i n g e r N a t u r e . A l l r i g h t s r e s e r v e d .

Background: There is no standardized definition of what a predatory journal is, nor have the characteristics of these journals been delineated or agreed upon. In order to study the phenomenon precisely a definition of predatory journals is needed. The objective of this scoping review is to summarize the literature on predatory journals, describe its epidemiological characteristics, and to extract empirical descriptions of potential characteristics of predatory journals. Methods: We searched five bibliographic databases: Ovid MEDLINE, Embase Classic + Embase, ERIC, and PsycINFO, and Web of Science on January 2nd, 2018. A related grey literature search was conducted March 27th, 2018. Eligible studies were those published in English after 2012 that discuss predatory journals. Titles and abstracts of records obtained were screened. We extracted epidemiological characteristics from all search records discussing predatory journals. Subsequently, we extracted statements from the empirical studies describing empirically derived characteristics of predatory journals. These characteristics were then categorized and thematically grouped.   Results: 920 records were obtained from the search. 344 of these records met our inclusion criteria. The majority of these records took the form of commentaries, viewpoints, letters, or editorials (78.44%), and just 38 records were empirical studies that reported empirically derived characteristics of predatory journals. We extracted 109 unique characteristics from these 38 studies, which we subsequently thematically grouped into six categories: journal operations, article, editorial and peer review, communication, article processing charges, and dissemination, indexing and archiving, and five descriptors.    Conclusions: This work identified a corpus of potential characteristics of predatory journals. Limitations of the work include our restriction to English language articles, and the fact that the methodological quality of articles included in our extraction was not assessed. These results will be provided to attendees at a stakeholder meeting seeking to develop a standardized definition for what constitutes a predatory journal.

Evidence supporting postoperative pain management using pregabalin as an adjunct intervention across various surgical pain models is lacking. The objective of this systematic review was to evaluate "model-specific" comparative effectiveness and harms of pregabalin following a previously published systematic review protocol. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from inception through August 2013. Data were screened and single extraction with independent verification and dual risk of bias assessment was performed. Quality of evidence (QoE) was rated using the GRADE approach. Primary outcomes were pain relief at rest and on movement and reduction in postoperative analgesic consumption. A total of 1423 records were screened, and 43 studies were included. Perioperative pregabalin resulted in: 16% (95% confidence interval [CI], 9%-21%) reduction in analgesic consumption (moderate QoE, 24 trials) and a small reduction in the magnitude of pain in surgeries associated with pronociceptive pain. Per 1000 patients, 10 more will experience blurred vision (95% CI, 5-20 more; moderate QoE, 17 trials) and 41 more sedation (95% CI, 13-77 more, 17 trials). To prevent 1 case of perioperative nausea and vomiting, the number needed to treat is 11 (95% CI: 7-28, 25 trials). Inadequate evidence addressed outcomes of enhanced recovery and serious harms. Pregabalin analgesic effectiveness is largely restricted to surgical procedures associated with pronociceptive mechanisms. The clinical significance of observed pregabalin benefits must be weighed against the uncertainties about serious harms and enhanced recovery to inform the careful selection of surgical patients. Recommendations for future research are proposed.

Reproducible research practices are underused in SRs of biomedical interventions. Adoption of such practices facilitates identification of errors and allows the SR data to be reanalyzed.

Background: Chronic periprosthetic joint infection (PJI) is a devastating complication that can occur following total joint replacement. Patients with chronic PJI report a substantially lower quality of life and face a higher risk of short-term mortality. Establishing a diagnosis of chronic PJI is challenging because of conflicting guidelines, numerous tests, and limited evidence. Delays in diagnosing PJI are associated with poorer outcomes and morbid revision surgery. The purpose of this systematic review was to compare the diagnostic accuracy of serum, synovial, and tissue-based tests for chronic PJI. Methods: This review adheres to the Cochrane Collaboration’s diagnostic test accuracy methods for evidence searching and syntheses. A detailed search of MEDLINE, Embase, the Cochrane Library, and the grey literature was performed to identify studies involving the diagnosis of chronic PJI in patients with hip or knee replacement. Eligible studies were assessed for quality and bias using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Meta-analyses were performed on tests with sufficient data points. Summary estimates and hierarchical summary receiver operating characteristic (HSROC) curves were obtained using a bivariate model. Results: A total of 12,616 citations were identified, and 203 studies met the inclusion criteria. Of these 203 studies, 170 had a high risk of bias. Eighty-three unique PJI diagnostic tests were identified, and 17 underwent meta-analyses. Laboratory-based synovial alpha-defensin tests and leukocyte esterase reagent (LER) strips (2+) had the best performance, followed by white blood-cell (WBC) count, measurement of synovial C-reactive protein (CRP) level, measurement of the polymorphonuclear neutrophil percentage (PMN%), and the alpha-defensin lateral flow test kit (Youden index ranging from 0.78 to 0.94). Tissue-based tests and 3 serum tests (measurement of interleukin-6 [IL-6] level, CRP level, and erythrocyte sedimentation rate [ESR]) had a Youden index between 0.61 to 0.75 but exhibited poorer performance compared with the synovial tests mentioned above. Conclusions: The quality of the literature pertaining to chronic PJI diagnostic tests is heterogeneous, and the studies are at a high risk for bias. We believe that greater transparency and more complete reporting in studies of diagnostic test results should be mandated by peer-reviewed journals. The available literature suggests that several synovial fluid-based tests perform well for diagnosing chronic PJI and their use is recommended in the work-up of any suspected case of chronic PJI. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.