Publication and related biases.

Abstract

Health Technology Assessment is indexed in Index Medicus/MEDLINE and Excerpta Medica/ EMBASE. Copies of the Executive Summaries are available from the NCCHTA website (see overleaf). NHS R&D HTA Programme T he overall aim of the NHS R&D Health Technology Assessment (HTA) programme is to ensure that high-quality research information on the costs, effectiveness and broader impact of health technologies is produced in the most efficient way for those who use, manage and work in the NHS. Research is undertaken in those areas where the evidence will lead to the greatest benefits to patients, either through improved patient outcomes or the most efficient use of NHS resources. The Standing Group on Health Technology advises on national priorities for health technology assessment. Six advisory panels assist the Standing Group in identifying and prioritising projects. These priorities are then considered by the HTA Commissioning Board supported by the National Coordinating Centre for HTA (NCCHTA). This report is one of a series covering acute care, diagnostics and imaging, methodology, pharmaceuticals, population screening, and primary and community care. It was identified as a priority by the Methodology Group and funded as project number 95/12/01. The views expressed in this publication are those of the authors and not necessarily those of the Standing Group, the Commissioning Board, the Panel members or the Department of Health. The editors wish to emphasise that funding and publication of this research by the NHS should not be taken as implicit support for the recommendations for policy contained herein. In particular, policy options in the area of screening will be considered by the National Screening Committee. This Committee, chaired by the Chief Medical Officer, will take into account the views expressed here, further available evidence and other relevant considerations. Reviews in Health Technology Assessment are termed 'systematic' when the account of the search, appraisal and synthesis methods (to minimise biases and random errors) would, in theory, permit the replication of the review by others. Criteria for inclusion in the HTA monograph series Reports are published in the HTA monograph series if (1) they have resulted from work either prioritised by the Standing Group on Health Technology, or otherwise commissioned for the HTA programme, and (2) they are of a sufficiently high scientific quality as assessed by the referees and editors.

Meta-analysis of anatomic resection versus nonanatomic resection for hepatocellular carcinoma

“…According to point of recurrence time from the date of hepatectomy, recurrences were classified into early (≤2 year) and late (>2 year) recurrences [34]. The prognosis of patients with early recurrent tumors was found to be worse than that of patients with late recurrence [35].…”

“…In addition, potential publication bias might be present, by not including unpublished studies. However, it was demonstrated that the use of unpublished data may not necessarily reduce the bias in meta-analysis [34,37].…”

Effects of species richness and elevated carbon dioxide on biomass accumulation: a synthesis using meta-analysis

“…Publication bias has been well recognized in scientiWc publications (Song et al 2000). Results from ecological studies, like those from any other Weld, are preferred by journals and therefore published more easily, if signiWcant treatment eVects were found (Jennions and Moller 2002;Kotiaho and Tomkins 2002;Moller and Jennions 2001).…”

Effects of Omega-3 Fatty Acid for Sudden Cardiac Death Prevention in Patients with Cardiovascular Disease: A Contemporary Meta-Analysis of Randomized, Controlled Trials

“…To assess the effect of individual studies on summary estimate of effect, we performed an influence analysis in which the pooled estimates were recalculated omitting one study at a time. We did not assess publication bias, because each subgroup pooled estimate included fewer than ten trials [17]. Analyses were conducted using Review Manager, version 5.0 (Copenhagen, The Nordic Cochrane Centre, The Cochrane Collaboration, 2008).…”