A conversation with Joseph Lau. All in the Family: systematic reviews, rapid reviews, scoping reviews, realist reviews, and more Spine surgery research: on and beyond current strategies. Tackling inequalities in obesity: a protocol for a systematic review of the effectiveness of public health interventions at reducing socioeconomic inequalities in obesity among adults Systematic reviews in endodontics--examples of GIGO? The Medical Review Article Revisited: Has the Science Improved? How to write an evidence-based clinical review article. Effects of workplace-based dietary and/or physical activity interventions for weight management targeting healthcare professionals: a systematic review of randomised controlled trials Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions. Financial Conflicts of Interest and Conclusions About Neuraminidase Inhibitors for Influenza
Dr. Joseph Lau is a world-leading expert in meta- analysis and systematic review s. Currently a professor in the Department of Health Services , Policy and Practice and co-director of the Center for Evidence -based Medicine at Brown University , Professor Lau has applied evidence -based methods to a variety of clinical , biomedical and healthcare topics ; has developed reliable and efficient methods and tools to conduct systematic review s and meta-analyses ; and has advanced an underst and ing on the impact of factors that may contribute to differences of results in scientific studies . His past research includes cumulative meta- analysis of r and omized controlled trials , comparison of results from large trials and meta-analyses of small trials , effect of baseline risk in the interpretation of clinical trial results , and empirical evaluation of existing methods of combining data . His current focus is on a Web-based repository of systematic review data , review s of diagnostic tests , nutrition , clinical practice guidelines , and dissemination of evidence -based methods to varied health-care disciplines . This report is a conversation from an adapted version of an interview , more or less chronologically arranged , between Joseph C. Cappelleri as interviewer and Joseph Lau as interviewee , with Meghan Ingerick recording and transcribing the interview Three years ago , we founded this journal focusing on publishing systematic review s , systematic review protocol s , and associated method ological development papers . Systematic review s , which developed in the social sciences in the 1970s , began to gain rapid momentum during the 1990s in response to concerns by policymakers and clinicians about the scientific validity of the prevailing paradigm of traditional narrative review s written by authoritative experts . What distinguished systematic review s was the use of formal explicit methods , in other words pre-specification , of what exactly was the question to be answered , how evidence was search ed for and assessed , and how it was synthesized in order to reach the conclusion . Importantly , these formal methods were described as part of the review itself in a Methods section . In turn , these methods themselves became the subject of hypothesis-testing studies , as investigators sought how best to search for evidence , assess studies for quality or risk of bias , determine under what conditions meta- analysis was justified , and how to best determine and characterize our confidence in the conclusions . The results of these hypothesis-testing studies led over time to improvements in the methods we use for systematic review s. Thus , systematic review s and this journal are part of an ever-evolving process whose foundations are rooted in the scientific method . Today , new forms of review s are appearing . These have emerged in response to policymakers and other stakeholders ’ needs for information , sometimes emergently or urgently , for which the existing systematic review model does not quite fit . Hence , the rapid review , when time is of the essence ; the scoping review , when what is needed is not detailed answers to specific questions but rather an overview of a broad field ; the evidence map , a cousin of scoping review s that commonly has a specific visual presentation of the evidence across a broad field ; and the realist review , where the question of interest includes how and why complex social interventions work in certain situations , rather than assume they either do or do not work at all . As Editors , we regularly get contacted by prospect i ve authors asking whether realist review s , or scoping review s , etc . , are “ within the scope ” for Systematic Review s , and therefore we judge it an opportune time to state our position on this matter . It is our view that all of these new forms of review s are related to systematic review s , similar to the way that different biological Species within the same Family are related to each other . We consider “ systematic review s ” to be the Family and the different forms of review s to be the different species . Just as in the biological classification , where the related organisms must share certain characteristics , so too must the different types of review s share a common characteristic . In this case , what is shared is their foundation in the scientific method , with their methods articulated in advance in sufficient detail that the review can be reproduced by others . A further defining feature is that there are scholars devoted to improving the methods over time via hypothesis-testing studies . Systematic Review s has responded to these emerging techniques and already publishes papers reporting methods and findings from the systematic review family and has for example published an extremely popular series on rapid review s. We would like to consoli date this position and invite su bmi ssion of these new species of review s , as long as they meet the qualifications just listed . We expect this process of evolution to continue and to refine the methods such that in 10 years ’ time , there will appear new , as yet unimagined species of review s— and perhaps some current species of review will become extinct . Thus , it is with the scientific method , which we believe is the foundation that unites the Family of systematic review BACKGROUND CONTEXT Systematic review s of the literature are powerful tools in evidence -based medicine . However , the design and report of systematic review s in spinal surgery contain many aspects amenable to improvement . PURPOSE To discuss the issues especially relevant for systematic review s in spinal surgery . METHODS From our experience of systematic review s and meta-analyses of clinical trials in  spinal surgery  , we infer guidance for the design and execution of systematic literature review s. RESULTS There are many difficulties associated with the design as well as conduct of clinical trials and consequently appraising evidence in spinal surgery . New treatments should be compared with the gold st and ard before other comparisons are investigated . Studies should present data as thoroughly as possible regarding all subgroups and follow-up moments , possibly in supplementary material . To provide the highest level of evidence , systematic review s should be as rigorously design ed as possible . CONCLUSIONS Gathering information on clinical effectiveness in spinal surgery can be improved both at the clinical study level and at the systematic review level . Alternatives to r and omized controlled trials such as comparative studies can be valuable tools on the clinical effectiveness of treatments in spinal surgery . The experience reflected in this article can support the scientific efforts in this field Background Socioeconomic inequalities in obesity and associated risk factors for obesity are widening throughout developed countries worldwide . Tackling obesity is high on the public health agenda both in the United Kingdom and internationally . However , what works in terms of interventions that are able to reduce inequalities in obesity is lacking . Methods / Design The review will examine public health interventions at the individual , community and societal level that might reduce inequalities in  obesity among adults aged 18 years and over , in any setting and in any country . The following electronic data bases will be search ed : MEDLINE , EMBASE , CINAHL , PsycINFO , Social Science Citation Index , ASSIA , IBSS , Sociological Abstract s , and the NHS Economic Evaluation Data base . Data base search es will be supplemented with website and gray literature search es . No studies will be excluded based on language , country or publication date . R and omized and non-r and omized controlled trials , prospect i ve and retrospective cohort studies ( with/without control groups ) and prospect i ve repeat cross-sectional studies ( with/without control groups ) that have a primary outcome that is a proxy for body fatness and have examined differential effects with regard to socioeconomic status ( education , income , occupation , social class , deprivation , poverty ) or where the intervention has been targeted specifically at disadvantaged groups or deprived areas will be included . Study inclusion , data extraction and quality appraisal will be conducted by two review ers . Meta- analysis and narrative synthesis will be conducted . The main analysis will examine the effects of 1 ) individual , 2 ) community and 3 ) societal level public health interventions on socioeconomic inequalities in adult obesity . Interventions will be characterized by their level of action and their approach to tackling inequalities . Context ual information on how such public health interventions are organized , implemented and delivered will also be examined . Discussion The review will provide evidence , and reveal any gaps in the evidence base , of public health strategies which reduce and prevent inequalities in the prevalence of obesity in adults and provide information on the organization , implementation and delivery of such interventions . Systematic review registration PROSPERO registration number : In many areas of medicine the amount of published information is increasing at an exponential rate , making it difficult for the clinician to condense the data to a manageable amount of valuable and useful information . Systematic review s have been suggested as a remedy for this information overload . Such review s are regarded as the highest level of evidence . Certain statistical methods , e.g. , meta- analysis , have also been introduced for the calculation of a more comprehensive summation of the compiled results from studies with small sample sizes . These findings would then serve as an authoritarian guide for evidence -based practice . Endodontists have lately jumped on the b and wagon of systematic review s and meta-analyses , and papers on various topics are being published . Well done , such comprehensive information would be very useful and authoritative for the practitioner . Alarmingly , the quality of these recent publications is negatively correlated to the frequency . This can have serious consequences in the clinical arena if spurious information is given a seal of approval when communicated as facts in refereed journals . A systematic literature review is design ed to focus on a single question and to synthesize all high- quality research reports relevant to the question . In these studies , however , sources of bias are often not controlled . Therefore , even the best review and meta- analysis becomes useless if it is based on poorly design ed research . Furthermore , these review s are mostly based on published data which are too often biased toward studies that show significant differences in results and /or outcome . “ Uninteresting ” conclusions tend not to be published . Endodontic literature , thus far , is short on well design ed and executed r and omized clinical trials . Furthermore , clinical protocol s often have many important “ proprietary ” modifications that make comparison difficult . This makes it very hard to undertake a systematic review to answer a narrow question . Such GIGO ( garbage in , garbage out ) can easily lead to biased conclusions and reinforce already existing biased comclusions . An example of such bias can be illustrated by a meta- analysis recently published . The study focused on assessing if there were differences in outcome between 1 and 2 treatment visits when treating teeth with apical periodontitis . Relevant publications on this topic are rare , and with the narrow inclusion criteria only 3 investigations were available for the review . However , the only factors connecting these 3 studies was the words “ single ” and “ two visits ” in the title . Beyond that , the selected studies are too different and inadequate for the study . Only 1 study is somewhat demonstrably r and omized , and outcome assessment s are based on 3 vastly different criteria . Two of the studies use calcium hydroxide as intracanal dressing , whereas the third uses no intervisit medication . Complexity of initial pathology and healing time are also clearly factors of great importance but not controlled . In addition , sample sizes in the component studies as well as the final cohort are all too small for the conclusions that there was no significant difference between 1or 2-visit treatment protocol s. To undertake and publish a meta- analysis on such an incomplete sample is counterproductive . Although the publication noted its numerous limitations , it will still communicate erroneous conclusions with a poor scientific foundation to the less informed reader . There are other examples of recently published systematic review s that are very ambiguous and tend to communicate spurious facts . One of these studies looks at the effect of smear-layer removal on sealing ability of root canal obturation . The study is entirely limited to laboratory experiments , with the majority of evaluations using dye leakage which is generally considered to be unreliable . This is an example of review ers lacking content expertise . The authors draw the conclusion , using defective review material , that removal of smear layer enhances the seal of the root filling . We may generally believe that this is the truth Review articles are an important element of most medical journals and a popular source of information for clinicians ( 1 ) . Given the increasing volume of medical literature and the limited time for reading that busy clinicians have , reliance on review articles is likely to increase . However , concerns have been raised that narrative , non systematic review articles may produce biased conclusions ( 2 , 3 ) . Mulrow ( 4 ) examined 50 review articles published in four major medical journals ( The New Engl and Journal of Medicine , Annals of Internal Medicine , JAMA , and Archives of Internal Medicine ) in 1985 - 1986 and found that none fulfilled 8 explicit criteria for scientifically sound summaries of the evidence . As a result , she and others ( 5 , 6 ) proposed criteria for conducting and evaluating review articles that would improve their quality ; these criteria are the first 10 listed in the Appendix Table . In a study of 36 review articles done by nine content experts and method ologists , these criteria were shown to yield reliable and valid estimates of the scientific quality of review s ( 7 , 8) . We sought to describe the methods used in recently published review articles and determine whether the attention paid to the method ologic shortcomings of review articles has led to improvements in their scientific quality . Methods By using the Science Citation Index ( 9 ) , we stratified the 12 general medicine journals that are considered core journals for ACP Journal Club ( 10 ) into those with high impact factors ( scores 5 ) and those with lower impact factors . We r and omly selected 3 ( The New Engl and Journal of Medicine , Annals of Internal Medicine , and JAMA ) of the 4 high-impact core journals and 3 ( British Medical Journal , American Journal of Medicine , and Journal of Internal Medicine ) of the 8 core journals with lower impact factors . The sampling frame included 3 of the 4 journals examined in Mulrow 's original study ( 4 ) . All 6 journals were h and - search ed by two of the investigators independently , and review articles published between January and December 1996 were retrieved . Review articles were defined as full-text articles published under the banner review that dealt with disease states ; had the words review , overview , or meta- analysis in the title or abstract ; or indicated in the text that the intention was to review or summarize the literature about a clinical topic . Editorials , correspondence , and conference summaries were excluded . Disagreements on article eligibility ( which occurred in five cases ) were resolved by consensus . After training with a test set of articles , five of the authors used explicit criteria ( Appendix Table ) to rate the identified review articles . So that the raters ' assessment s would be blinded , the articles ' authors , author affiliations , and sources of articles were masked . The first 10 criteria in the Appendix Table ( hereafter referred to as method ologic criteria ) have been previously vali date d ( 7 ) and assess method ologic rigor , whereas the last five criteria were developed for this study to evaluate the scientific basis of treatment recommendations . Because inter-rater agreement was excellent on the test set ( overall agreement , 94 % ) , each rater was assigned a r and om sample of 20 % of the articles . One rater independently evaluated a r and om sample of five articles from each rater to assess inter-rater reliability for the criteria . The mean value was 0.79 , indicating substantial agreement ; overall agreement was 95 % and ranged from 84 % for criteria 1 and 6 to 100 % for criteria 2 , 3 , and 5 . After we determined the number of criteria fulfilled by each article , the number of articles meeting each criterion was ascertained . The proportion of review s from high-impact journals and from lower-impact journals that met each criterion were compared . Only the subset of review s containing treatment recommendations were used for the comparisons for criteria 7 to 15 . The chi-square test was used and 95 % CIs for the observed differences were calculated for all comparisons . In addition , articles identified as meta-analyses , systematic review s , or overviews in their title , abstract , or text were compared with the remaining review articles for each criterion ( again by using the chi-square test and by limiting analysis to those that included treatment recommendations for criteria 7 to 15 ) . Logistic regression analysis was used to adjust for journal of publication . The funding organizations were not involved in the design , conduct , analysis , or reporting of this study . Results A total of 158 review articles were identified : 60 from The New Engl and Journal of Medicine , 33 from Annals of Internal Medicine , 24 from British Medical Journal , 18 from American Journal of Medicine , 13 from JAMA , and 10 from Journal of Internal Medicine . ( A full list of the included articles is available from Dr. McAlister on request . ) Most review s were written by more than one author ( median number of authors , 2 [ range , 1 to 10 authors ] ) , and 111 review s ( 70 % ) made treatment recommendations . Although most articles had sections review ing the relevant pathophysiology and pharmacodynamics , 19 articles ( 12 % ) were largely basic science review s. Only 2 review s met all 10 method ologic criteria ; the median number of criteria fulfilled was one ( Figure ) . Nineteen ( 12 % ) of the review articles were described as meta- analysis , systematic review , or overview in the title or abstract ; 12 of these 19 articles were published in high-impact journals . A higher proportion of these articles met the method ologic criteria ( Appendix Table ) ; the comparisons for all but criterion 6 were statistically significant , even after adjustment for journal of publication ( P<0.005 for all comparisons ) . Although there was significant heterogeneity among journals ( P<0.005 for criteria 1 to 5 , 7 , and 8) , review articles published in high-impact journals did not meet method ologic criteria more frequently than those published in other journals ( Table ) . Exclusion of the review s from one journal with method ologic scores that were significantly lower than the rest ( P<0.001 for all comparisons ) resolved much of the interjournal heterogeneity and revealed that review s published in the remaining high-impact journals more often met some ( but not all ) of the method ologic criteria ( Table ) . Figure . Percentage of 158 review articles published in 1996 that fulfilled specific method ologic criteria . Table . Comparison of Methods Used in 1996 Review Articles , by Journal Impact Factor The 44 articles that described how evidence was located used the following sources ( which were not mutually exclusive ) : MEDLINE ( 42 articles ) , h and search of reference lists from published studies or review articles ( 30 articles ) , other electronic data bases ( 14 articles ) , contact with experts in the field ( 10 articles ) , h and search of relevant journals ( 7 articles ) , and contact with the pharmaceutical industry ( 5 articles ) . Of the 22 review s that included a description of the electronic search strategy , the search was restricted to English- language publications in 11 . Of the 111 review s in which treatment recommendations were made , a median of 3 therapies ( range , 1 to 23 therapies ) were discussed . The 16 meta-analyses that included treatment recommendations were more focused , examining a median of 1 therapy ( range , 1 to 6 therapies ) . The scientific basis of these recommendations is outlined in the last five criteria of the Appendix Table . Discussion In summary , only a minority of the review articles published in six widely read general medical journals specified rigorous , systematic methods of identifying , evaluating , and synthesizing the evidence , thereby raising concerns about the validity of their conclusions and recommendations ( 11 ) . Furthermore , although most review articles made recommendations for therapeutic options , their clinical relevance may be limited : Only one third discussed benefits and harms of the treatment options , only 6 % mentioned the relative or absolute costs of the various options , less than half provided an estimate of the anticipated treatment effect , and very few presented the results in clinical ly relevant formats that would be easily understood by clinicians . Although there is still substantial room for improvement , these results do represent progress from the situation in 1985 - 1986 ( Appendix Table ) . A higher proportion of recently published review s specify how the evidence was identified and synthesized . This same pattern was observed in a recent study of oncology review articles published in a single journal between 1983 and 1995 ( 12 ) . Similarly , our findings for meta-analyses published in these journals in 1996 are consistent with contemporaneous investigations in other fields and represent substantial improvement over the state of affairs in the mid-1980s ( 13 , 14 ) . Our study had several potential limitations . First , the authors of articles in which systematic methods were not specified may have used such methods but not reported them ( or the journal may have removed the details of the methods in prepublication ) . However , preliminary evidence suggests that there is little difference between the conduct of studies and their published methods ( 7 , 15 ) . In other words , if what was done is not reported , there is a good chance that it was not done rigorously ( 7 ) . Second , our finding that meta-analyses are more scientifically rigorous than other review s may be seen as tautological because the criteria used in this study may be used by meta-analysts in performing their studies . However , meta-analysts disagree over some issues of methodology , and published meta-analyses often vary in the quality of their reports ( 13 ) . Third , the practical importance of the method ologic flaws identified in these review s is difficult to ascertain . We lack empirical evidence that review s with explicit , systematic methods yield results closer to the truth , but it is known that non systematic review s are more prone to r and om and Traditional clinical review articles , also known as up date s , differ from systematic review s and meta-analyses . Up date s selectively review the medical literature while discussing a topic broadly . Non-quantitative systematic review s comprehensively examine the medical literature , seeking to identify and synthesize all relevant information to formulate the best approach to diagnosis or treatment . Meta-analyses ( quantitative systematic review s ) seek to answer a focused clinical question , using rigorous statistical analysis of pooled research studies . This article presents guidelines for writing an evidence -based clinical review article for American Family Physician . First , the topic should be of common interest and relevance to family practice . Include a table of the continuing medical education objectives of the review . State how the literature search was done and include several sources of evidence -based review s , such as the Cochrane Collaboration , BMJ 's Clinical Evidence , or the InfoRetriever Web site . Where possible , use evidence based on clinical outcomes relating to morbidity , mortality , or quality of life , and studies of primary care population s. In articles su bmi tted to American Family Physician , rate the level of evidence for key recommendations according to the following scale : level A ( r and omized controlled trial [ RCT ] , meta- analysis ) ; level B ( other evidence ) ; level C ( consensus/expert opinion ) . Finally , provide a table of key summary points Background The prevalence of overweight and obesity is high amongst healthcare professionals and there is growing interest in delivering weight loss interventions in the workplace . We conducted a systematic review to ( i ) examine the effectiveness of workplace-based diet and /or physical activity interventions aim ed at healthcare professionals and to ( ii ) identify and describe key components of effective interventions . Seven electronic data bases were systematic ally search ed . Results Thirteen r and omised controlled trials met the inclusion criteria , of which seven had data available for meta- analysis . Where meta- analysis was possible , studies were grouped according to length of follow-up ( < 12 months and ≥12 months ) and behavioural target ( diet only , physical activity only or diet and physical activity ) , with outcome data pooled using a weighted r and om effects model . Nine studies reported statistically significant ( between-group ) differences . Four studies reported being informed by a behaviour change theory . Meta- analysis of all trials reporting weight data demonstrated healthcare professionals allocated to dietary and physical activity interventions lost significantly more body weight ( −3.95 Kg , [ 95 % CI −4.96 to- 2.95 Kg ] ) than controls up to 12 months follow up . Conclusions Workplace diet and /or physical activity interventions targeting healthcare professionals are limited in number and are heterogeneous . To improve the evidence base , we recommend additional evaluations of theory-based interventions and adequate reporting of intervention content BACKGROUND Systematic review s may be compromised by selective inclusion and reporting of outcomes and analyses . Selective inclusion occurs when there are multiple effect estimates in a trial report that could be included in a particular meta- analysis ( e.g. from multiple measurement scales and time points ) and the choice of effect estimate to include in the meta- analysis is based on the results ( e.g. statistical significance , magnitude or direction of effect ) . Selective reporting occurs when the reporting of a subset of outcomes and analyses in the systematic review is based on the results ( e.g. a protocol -defined outcome is omitted from the published systematic review ) . OBJECTIVES To summarise the characteristics and synthesis e the results of empirical studies that have investigated the prevalence of selective inclusion or reporting in systematic review s of r and omised controlled trials ( RCTs ) , investigated the factors ( e.g. statistical significance or direction of effect ) associated with the prevalence and quantified the bias . SEARCH METHODS We search ed the Cochrane Methodology Register ( to July 2012 ) , Ovid MEDLINE , Ovid EMBASE , Ovid PsycINFO and ISI Web of Science ( each up to May 2013 ) , and the US Agency for Healthcare Research and Quality ( AHRQ ) Effective Healthcare Program 's Scientific Re source Center ( SRC ) Methods Library ( to June 2013 ) . We also search ed the abstract books of the 2011 and 2012 Cochrane Colloquia and the article alerts for method ological work in research synthesis published from 2009 to 2011 and compiled in Research Synthesis Methods . SELECTION CRITERIA We included both published and unpublished empirical studies that investigated the prevalence and factors associated with selective inclusion or reporting , or both , in systematic review s of RCTs of healthcare interventions . We included empirical studies assessing any type of selective inclusion or reporting , such as investigations of how frequently RCT outcome data is selectively included in systematic review s based on the results , outcomes and analyses are discrepant between protocol and published review or non-significant outcomes are partially reported in the full text or summary within systematic review s. DATA COLLECTION AND ANALYSIS Two review authors independently selected empirical studies for inclusion , extracted the data and performed a risk of bias assessment . A third review author resolved any disagreements about inclusion or exclusion of empirical studies , data extraction and risk of bias . We contacted authors of included studies for additional unpublished data . Primary outcomes included overall prevalence of selective inclusion or reporting , association between selective inclusion or reporting and the statistical significance of the effect estimate , and association between selective inclusion or reporting and the direction of the effect estimate . We combined prevalence estimates and risk ratios ( RRs ) using a r and om-effects meta- analysis model . MAIN RESULTS Seven studies met the inclusion criteria . No studies had investigated selective inclusion of results in systematic review s , or discrepancies in outcomes and analyses between systematic review registry entries and published systematic review s. Based on a meta- analysis of four studies ( including 485 Cochrane Review s ) , 38 % ( 95 % confidence interval ( CI ) 23 % to 54 % ) of systematic review s added , omitted , up grade d or down grade d at least one outcome between the protocol and published systematic review . The association between statistical significance and discrepant outcome reporting between protocol and published systematic review was uncertain . The meta-analytic estimate suggested an increased risk of adding or upgrading ( i.e. changing a secondary outcome to primary ) when the outcome was statistically significant , although the 95 % CI included no association and a decreased risk as plausible estimates ( RR 1.43 , 95 % CI 0.71 to 2.85 ; two studies , n = 552 meta-analyses ) . Also , the meta-analytic estimate suggested an increased risk of downgrading ( i.e. changing a primary outcome to secondary ) when the outcome was statistically significant , although the 95 % CI included no association and a decreased risk as plausible estimates ( RR 1.26 , 95 % CI 0.60 to 2.62 ; two studies , n = 484 meta-analyses ) . None of the included studies had investigated whether the association between statistical significance and adding , upgrading or downgrading of outcomes was modified by the type of comparison , direction of effect or type of outcome ; or whether there is an association between direction of the effect estimate and discrepant outcome reporting . Several secondary outcomes were reported in the included studies . Two studies found that reasons for discrepant outcome reporting were infrequently reported in published systematic review s ( 6 % in one study and 22 % in the other ) . One study ( including 62 Cochrane Review s ) found that 32 % ( 95 % CI 21 % to 45 % ) of systematic review s did not report all primary outcomes in the abstract . Another study ( including 64 Cochrane and 118 non-Cochrane review s ) found that statistically significant primary outcomes were more likely to be completely reported in the systematic review abstract than non-significant primary outcomes ( RR 2.66 , 95 % CI 1.81 to 3.90 ) . None of the studies included systematic review s published after 2009 when reporting st and ards for systematic review s ( Preferred Reporting Items for Systematic review s and Meta-Analyses ( PRISMA ) Statement , and Method ological Expectations of Cochrane Intervention Review s ( MECIR ) ) were disseminated , so the results might not be generalisable to more recent systematic review s. AUTHORS ' CONCLUSIONS Discrepant outcome reporting between the protocol and published systematic review is fairly common , although the association between statistical significance and discrepant outcome reporting is uncertain . Complete reporting of outcomes in systematic review abstract s is associated with statistical significance of the results for those outcomes . Systematic review outcomes and analysis plans should be specified prior to seeing the results of included studies to minimise post-hoc decisions that may be based on the observed results . Modifications that occur once the review has commenced , along with their justification , should be clearly reported . Effect estimates and CIs should be reported for all systematic review outcomes regardless of the results . The lack of research on selective inclusion of results in systematic review s needs to be addressed and studies that avoid the method ological weaknesses of existing research are also needed Industry funding and author financial conflicts of interest may influence the production and synthesis of scientific evidence ( 1 ) . Associations with the pharmaceutical company developing and marketing a drug have been found to influence the design of trials ( 2 ) , the conduct of trials ( 3 ) , and the reporting of trial results ( 47 ) . Furthermore , financial ties and industry funding seem to result in greater rates of favorable conclusions in clinical trials examining new drugs ( 812 ) . Fewer studies have considered the potential influence of financial conflicts of interest on the synthesis of clinical evidence in systematic review s ( 13 , 14 ) . Neuraminidase inhibitors , which are used in the prophylaxis and treatment of seasonal and p and emic influenza , have been the subject of ongoing uncertainty about their specific clinical benefits ( 15 , 16 ) . This is the result of not only the continuing emergence of strains with unknown drug responses but also the increasing awareness in the medical community that , until recently , its knowledge of the safety and efficacy of these drugs has been incomplete ( 17 ) . Despite the abundance of clinical trials and publications on neuraminidase inhibitors , the details of many key trials had not been disclosed ( 18 , 19 ) . As a result , systematic review ers analyzing and synthesizing evidence on the effectiveness of these agents have faced incomplete information , unresolved discrepancies in the data , and a high risk of publication and reporting biases among the primary clinical trials ( 20 , 21 ) . This prompted extensive efforts to access complete records of all published and unpublished clinical trials from manufacturers , culminating in the publication of several review s on the basis of comprehensive clinical study reports and potentially changing the way systematic review s will be undertaken in the future ( 2227 ) . Review s of neuraminidase inhibitors exhibit wide variation in their conclusions , ranging from strong endorsements of the use of these agents in the prophylaxis and treatment of influenza ( 28 , 29 ) to more conservative assessment s question ing the evidence on the drugs ' safety and efficacy ( 15 , 30 ) . The reasons for this discordance in review conclusions are likely multifactorial and may be related in part to the manner in which evidence is accessed , synthesized , and presented ( 23 , 27 ) , both in terms of the numerical results and the authors ' emphasis and interpretation ( 31 , 32 ) . Our aim was to determine whether there is an association between financial conflicts of interest and the favorable presentation of evidence in systematic review s on the use of neuraminidase inhibitors for the prophylaxis and treatment of influenza . Methods Data Sources Systematic review s were identified in PubMed , PubMed In Process , EMBASE , and the Cochrane Data base of Systematic Review s. Search es were done using the keywords influenza , neuraminidase inhibitors , oseltamivir , zanamivir , peramivir , and laninamivir . Articles were retrieved if the search terms appeared in the title or abstract or were included as data base-specific keywords . In PubMed and EMBASE , search es were also constrained to review publication types . We limited our search to English- language articles published since 1 January 2005 . These articles were manually review ed to identify those that focused on the use of neuraminidase inhibitors for influenza prophylaxis or treatment ( such as excluded articles primarily about drug development or other manufacturing processes ) . We selected all review s that used a systematic search protocol , which we defined as the inclusion and reporting of an explicit search strategy , including reasons for subsequent exclusion of articles . The final search es were done on 26 May 2014 . Cochrane review s are periodically up date d to incorporate new evidence , and the results and conclusions are resynthesized as indicated . The authors of these review s are typically different , and there may be differences in the methods as well as the results and language of the review . These up date d review s were included separately . Other Cochrane review s are occasionally rewritten by a subset of the authors for publication in medical journals as abridged versions to increase dissemination . These reports have separate peer review s and are prepared on the basis of a selection of the complete results . We considered these review s separately as well but also did a sensitivity analysis in which they were combined with the original Cochrane review s. Data Extraction Financial conflicts of interest were identified for all authors of the review s and included affiliations with or funding from the pharmaceutical company manufacturing any of the neuraminidase inhibitors under review . We defined financial conflicts of interest as employment , the funding of grants paid to an author or an author 's research group , and the funding of medical writers for the systematic review . These financial conflicts of interest were identified using information about affiliations or funding listed in the systematic review s , as well as in any other articles published by one of the authors during the 3 years before the publication of the index systematic review . In addition , we search ed authors ' personal and institutional Web sites ; lists of disclosures from GlaxoSmithKline ( Research Triangle Park , North Carolina ) and Roche Pharmaceuticals ( Basel , Switzerl and ) ; and performed Web search es combining the names of the authors , drugs , and pharmaceutical companies to identify any additional information about financial relationships . Details of the specific financial conflicts of interest identified for each author are listed in Appendix Table 1 . Appendix Table 1 . Financial Conflicts of Interest Among Authors of the Systematic Review s For each systematic review , we recorded whether prophylaxis or treatment was assessed , the forms of evidence to be included ( such as r and omized , controlled trials and observational studies ) , the specific clinical outcomes assessed , the population s examined , and whether meta-analyses were done . We also examined whether the review s included information about the validity or quality of the primary literature . In particular , we recorded whether there were statements addressing nonpublication of primary studies or publication bias , including tests done by the review ers to assess for bias in meta-analyses ( such as the Egger or Begg test [ 33 , 34 ] ) , difficulty in accessing comprehensive study data , and the prevalence or role of industry in conducting and funding the primary studies . Data Analysis Two investigators were provided with redacted copies of each review that did not include the review s ' authors , their affiliations , or information on financial conflicts of interest . These versions also did not contain the journal name , journal formatting , or the article 's acknowledgments or references . The investigators independently evaluated the review s and classified the prophylaxis and treatment assessment s as favorable or not favorable toward the use of neuraminidase inhibitors . They were instructed to do this grading on the basis of the entirety of the review text without restriction to conclusions or recommendations made in any specific section of the review , thus allowing them to take into account the emphasis and interpretation of the authors throughout the review . The agreement between the investigators was strong at 86 % ( Cohen , 0.72 ; P < 0.001 ) . Disagreements were resolved by a third investigator using the same redacted copies . Descriptive analyses were done to examine the associations between financial conflicts of interest and the grading of the systematic review s. A sensitivity analysis excluding the summary review s was done to further examine this association . We also assessed the association between financial conflicts of interest and the inclusion of statements addressing the validity or quality of the primary evidence . Role of the Funding Source This study was funded by the Australian National Health and Medical Research Council . The funding source had no role in the design and conduct of the study , analysis of the results , or the decision to su bmi t the manuscript for publication . Results We identified 827 published articles across the 4 data bases using the specified search criteria , with 26 systematic review s included in the final cohort ( Figure ) . Thirteen review s examined prophylaxis and 24 examined treatment of influenza , accounting for 37 distinct assessment s ( Appendix Table 2 ) . In terms of review methods , 7 were Cochrane systematic review s and 19 conducted and reported a meta- analysis ( 73 % ) . The evidence inclusion criteria were limited to r and omized , controlled trials for 14 of the systematic review s ( 54 % ) , and 5 included evidence from clinical study reports or patient-level data . The main population s examined were healthy adults ( 18 of 26 systematic review s ) , children ( 13 of 26 ) , and hospitalized patients ( 6 of 24 ) . The outcome measures for prophylaxis assessment s included influenza-like illness and laboratory-confirmed influenza . For the treatment assessment s , the outcomes were illness duration , influenza-related complications , hospitalization , and mortality , mostly in combination . Five review s were up date s of previous Cochrane review s , and 3 were summary review s based on Cochrane review s. Figure . Summary of evidence search and selection . Eligible systematic review s included those with outcomes related to the prophylaxis or treatment of influenza . Appendix Table 2 . Characteristics of Systematic Review s Examining Prophylaxis and Treatment Outcomes for Neuraminidase Inhibitors Association Between Financial Conflicts of Interest and Favorable Assessment s Seven of the 26 systematic review s ( 27 % ) , corresponding to 8 of the 37 assessment s ( 22 % ) , were associated with a financial conflict of interest ( Appendix Table 1 ) . We identified financial conflicts of interest in publications other than the index systematic review in 2 cases , and no additional
There is no consistent result in the relationship between obesity and timing of pubertal onset in boys .
Obesity may contribute to early onset of puberty in girls , while in boys , there is insufficient data .
This systematic review and meta- analysis examined the associations between obesity and puberty timing based on scientific evidence .