Financial ties and concordance between results and conclusions in meta-analyses: retrospective cohort study

Drug firms, the codification of diagnostic categories, and bias in clinical guidelines

The possibility that industry is exerting an undue influence on the culture of medicine has profound implications for the profession's public health mission. Policy analysts, investigative journalists, researchers, and clinicians have questioned whether academic-industry relationships have had a corrupting effect on evidence-based medicine. Psychiatry has been at the heart of this epistemic and ethical crisis in medicine. This article examines how commercial entities, such as pharmaceutical companies, influence psychiatric taxonomy and treatment guidelines. Using the conceptual framework of institutional corruption, we show that organized psychiatry's dependence on drug firms has led to a distortion of science. We describe the current dependency corruption and argue that transparency alone is not a solution. We conclude by taking the position that the corruption of the evidence base in diagnostic and practice guidelines has compromised the informed consent process, and we suggest strategies to address this problem.

Public health, academic medicine, and the alcohol industry's corporate social responsibility activities

We explored the emerging relationships among the alcohol industry, academic medicine, and the public health community in the context of public health theory dealing with corporate social responsibility. We reviewed sponsorship of scientific research, efforts to influence public perceptions of research, dissemination of scientific information, and industry-funded policy initiatives. To the extent that the scientific evidence supports the reduction of alcohol consumption through regulatory and legal measures, the academic community has come into increasing conflict with the views of the alcohol industry. We concluded that the alcohol industry has intensified its scientific and policy-related activities under the general framework of corporate social responsibility initiatives, most of which can be described as instrumental to the industry's economic interests.

Reporting of conflicts of interest from drug trials in Cochrane reviews: cross sectional study

OBJECTIVES

To investigate the degree to which Cochrane reviews of drug interventions published in 2010 reported conflicts of interest from included trials and, among reviews that reported this information, where it was located in the review documents.

DESIGN

Cross sectional study.

DATA SOURCES

Cochrane Database of Systematic Reviews.

SELECTION CRITERIA

Systematic reviews of drug interventions published in 2010 in the Cochrane Database of Systematic Reviews, with review content classified as up to date in 2008 or later and with results from one or more randomised controlled trials.

RESULTS

Of 151 included Cochrane reviews, 46 (30%, 95% confidence interval 24% to 38%) reported information on the funding sources of included trials, including 30 (20%, 14% to 27%) that reported information on trial funding for all included trials and 16 (11%, 7% to 17%) that reported for some, but not all, trials. Only 16 of the 151 Cochrane reviews (11%, 7% to 17%) provided any information on trial author-industry financial ties or trial author-industry employment. Information on trial funding and trial author-industry ties was reported in one to seven locations within each review, with no consistent reporting location observed.

CONCLUSIONS

Most Cochrane reviews of drug trials published in 2010 did not provide information on trial funding sources or trial author-industry financial ties or employment. When this information was reported, location of reporting was inconsistent across reviews.

Those who have the gold make the evidence: how the pharmaceutical industry biases the outcomes of clinical trials of medications

Pharmaceutical companies fund the bulk of clinical research that is carried out on medications. Poor outcomes from these studies can have negative effects on sales of medicines. Previous research has shown that company funded research is much more likely to yield positive outcomes than research with any other sponsorship. The aim of this article is to investigate the possible ways in which bias can be introduced into research outcomes by drawing on concrete examples from the published literature. Poorer methodology in industry-funded research is not likely to account for the biases seen. Biases are introduced through a variety of measures including the choice of comparator agents, multiple publication of positive trials and non-publication of negative trials, reinterpreting data submitted to regulatory agencies, discordance between results and conclusions, conflict-of-interest leading to more positive conclusions, ghostwriting and the use of "seeding" trials. Thus far, efforts to contain bias have largely focused on more stringent rules regarding conflict-of-interest (COI) and clinical trial registries. There is no evidence that any measures that have been taken so far have stopped the biasing of clinical research and it's not clear that they have even slowed down the process. Economic theory predicts that firms will try to bias the evidence base wherever its benefits exceed its costs. The examples given here confirm what theory predicts. What will be needed to curb and ultimately stop the bias that we have seen is a paradigm change in the way that we treat the relationship between pharmaceutical companies and the conduct and reporting of clinical trials.

Discordance between conclusions stated in the abstract and conclusions in the article: analysis of published randomized controlled trials of systemic therapy in lung cancer

PURPOSE

Clinicians may read only the abstract of an article to keep abreast of newly published randomized controlled trials (RCTs). However, discordances have been noticed in summary conclusions in the abstracts and the main body of some articles. This article evaluated such discordances in detail.

METHODS

RCTs of systemic therapy for lung cancer published between 2004 and 2009 were considered. Conclusions in the body of the articles and those in the abstracts were graded by using a 7-point Likert scale; 1 for strong endorsement of the control arm, 4 for a neutral statement, and 7 for strong endorsement of the experimental arm. Conclusions were classified as discordant if the difference in scores was ≥ 2. χ(2) tests and logistic regression were used to identify factors associated with discordance.

RESULTS

From among 114 eligible RCTs identified (90 for non-small-cell and 24 for small-cell lung cancer), 11 (10%) articles presented discordant conclusions in the abstract and in the body of the articles. Discordance was most common when the experimental arm was strongly supported in the abstract but not in the body of the article (nine of 11; 82%); however, the converse was much less common (two of 11; 18%; P < .001). Intraclass correlations for the two reviewers were ≥ 0.9. The discordances were found to be independent of trial-related factors.

CONCLUSION

Conclusive statements in the abstract can differ from those in the full text. Clinicians should use caution when they consider making changes in their practice on the basis of reading only the abstract of a published RCT.

Industry influenced evidence production in collaborative research communities: a network analysis

OBJECTIVE

To measure the relative influence that industry authors have on collaborative research communities and evidence production.

STUDY DESIGN AND SETTING

Using 22 commonly prescribed drugs, 6,711 randomized controlled trials (RCTs), and 28,104 authors, 22 collaboration networks were constructed and analyzed. The directly industry-affiliated (DIA) authors were identified in the networks according to their published affiliations. Measures of influence (network centrality) and impact (citations) were determined for every author. Network-level measures of community structure and collaborative preference were used to further characterize the groups.

RESULTS

Six percent (1,741 of 28,104) of authors listed a direct affiliation with the manufacturer of a drug evaluated in the RCT. These authors received significantly more citations (P<0.05 in 19 networks) and were significantly more central in the networks (P<0.05 in 20 networks). The networks show that DIA authors tend to have greater reach in the networks and collaborate more often with non-DIA authors despite a preference toward their own group. Potential confounders include publication bias, trial sizes, and conclusions.

CONCLUSIONS

Industry-based authors are more central in their networks and are deeply embedded within highly connected drug research communities. As a consequence, they have the potential to influence information flow in the production of evidence.

Consistency in the Analysis and Reporting of Primary End Points in Oncology Randomized Controlled Trials From Registration to Publication: A Systematic Review

Purpose

To improve the quality of reporting of randomized clinical trials (RCTs), international registries for RCTs and guidelines for primary end point (PEP) analysis were established. The objectives of this systematic review were to evaluate concordance of PEP between publication and the corresponding registry and to assess intrapublication consistency in PEP reporting.

Methods

All adult oncology RCTs in solid tumors published in 10 journals between 2005 and 2009 were reviewed. Registration information was extracted from international trial registries.

Results

A total 366 RCTs were identified. Trial registration was found for 215 trials, and the rate increased from 43% in 2005 to 82% in 2009 (P < .001). There were 134 RCTs with clearly defined PEPs in registry, with the rate increasing from 15% to 67% (P < .001). PEP differed between registration and final publication in 14% trials with clearly defined PEPs. Reporting issues in methodology were found in 15% of RCTs, mainly because of inadequate reporting of PEP or sample size calculation. Problems with the interpretation of trial results were found in 22% publications, mostly resulting from negative superiority studies being interpreted as showing equivalence.

Conclusion

The rates of trial registration and of trials with clearly defined PEPs have improved over time; however, 14% of these trials reported a different PEP in the final publication. Intrapublication inconsistencies in PEP reporting are frequent. Our findings highlight the need for investigators, peer reviewers, and readers to exercise increased awareness and scrutiny of reporting outcomes of oncology RCTs.

Is meta-analysis the platinum standard of evidence?

An astonishing volume and diversity of evidence is available for many hypotheses in the biomedical and social sciences. Some of this evidence-usually from randomized controlled trials (RCTs)-is amalgamated by meta-analysis. Despite the ongoing debate regarding whether or not RCTs are the 'gold-standard' of evidence, it is usually meta-analysis which is considered the best source of evidence: meta-analysis is thought by many to be the platinum standard of evidence. However, I argue that meta-analysis falls far short of that standard. Different meta-analyses of the same evidence can reach contradictory conclusions. Meta-analysis fails to provide objective grounds for intersubjective assessments of hypotheses because numerous decisions must be made when performing a meta-analysis which allow wide latitude for subjective idiosyncrasies to influence its outcome. I end by suggesting that an older tradition of evidence in medicine-the plurality of reasoning strategies appealed to by the epidemiologist Sir Bradford Hill-is a superior strategy for assessing a large volume and diversity of evidence.

Relationships between medicine and industry: approaches to the problem of conflicts of interest

Relationships between physicians and industry are prevalent in medical education, clinical practice, and research, as well as at the level of medical institutions. These relationships can be valuable for the advancement of medicine but have also received increased scrutiny in recent years because they create conflicts of interest that pose a risk of biasing the judgments of physicians. Responses to these conflicts of interest by medical institutions, journals, and governments have utilized four main tools: education, disclosure, management, and prohibition. Each of the four has its advantages and drawbacks. Medicine faces the challenge of tailoring the use of these tools to minimize the risk of bias while allowing useful medical-industry collaborations to proceed. Viewing the dilemmas created by physicians' relationships with industry as a version of the principal-agent problem, which is much discussed by economists, may help in developing creative approaches to these issues.

Ethics and technology transfer: patients, patents, and public trust

Universities and academic medical centers have been increasing their focus on technology transfer and research commercialization. With this shift in focus, academic-industry ties have become prevalent. These relationships can benefit academic researchers and help then to transform their research into tangible societal benefits. However, there also are concerns that these ties and the greater academic focus on commercialization might lead to conflicts of interest, especially financial conflicts of interest. This paper briefly explores some of these conflicts of interest, particularly relating to research and training. This paper also discusses some of the policies that have been, and are being, developed to try to mitigate and manage these conflicts so that academic involvement in technology transfer and commercialization can continue without jeopardizing academic work or the public's trust in them.

Ethics and technology transfer: patients, patents, and public trust

Universities and academic medical centers have been increasing their focus on technology transfer and research commercialization. With this shift in focus, academic-industry ties have become prevalent. These relationships can benefit academic researchers and help then to transform their research into tangible societal benefits. However, there also are concerns that these ties and the greater academic focus on commercialization might lead to conflicts of interest, especially financial conflicts of interest. This paper briefly explores some of these conflicts of interest, particularly relating to research and training. This paper also discusses some of the policies that have been, and are being, developed to try to mitigate and manage these conflicts so that academic involvement in technology transfer and commercialization can continue without jeopardizing academic work or the public's trust in them.

Antidepressants and breast and ovarian cancer risk: a review of the literature and researchers' financial associations with industry

Background

Antidepressant (AD) use has been purported to increase the risk of breast and ovarian cancer, although both epidemiological and pre-clinical studies have reported mixed results [1]–[6]. Previous studies in a variety of biomedical fields have found that financial ties to drug companies are associated with favorable study conclusions [7].

Methods and Findings

We searched English-language articles in MEDLINE, PsychINFO, the Science Citations Index and the Cochrane Central Register of Controlled Clinical Trials (through November 2010). A total of 61 articles that assessed the relationship between breast and ovarian cancer and AD use and articles that examined the effect of ADs on cell growth were included. Multi-modal screening techniques were used to investigate researchers' financial ties with industry. A random effects meta-analysis was used to pool the findings from the epidemiological literature. Thirty-three percent (20/61) of the studies reported a positive association between ADs and cancer. Sixty-seven percent (41/61) of the studies reported no association or antiproliferative effect. The pooled odds ratio for the association between AD use and breast/ovarian cancer in the epidemiologic studies was 1.11 (95% CI, 1.03–1.20). Researchers with industry affiliations were significantly less likely than researchers without those ties to conclude that ADs increase the risk of breast or ovarian cancer. (0/15 [0%] vs 20/46 [43.5%] (Fisher's Exact test P = 0.0012).

Conclusions

Both the pre-clinical and clinical data are mixed in terms of showing an association between AD use and breast and ovarian cancer. The possibility that ADs may exhibit a bi-phasic effect, whereby short-term use and/or low dose antidepressants may increase the risk of breast and ovarian cancer, warrants further investigation. Industry affiliations were significantly associated with negative conclusions regarding cancer risk. The findings have implications in light of the 2009 USPSTF guidelines for breast cancer screening and for the informed consent process.

Vulnerability of health to market forces

OBJECTIVES

This article reviews adverse influences of for-profit enterprises on health care and public health, and examines significance for public policy.

RESEARCH DESIGN

Narrative review.

RESULTS

For-profit health-care industries may increase costs and reduce quality, leading to market failure and contributing to the USA's unflattering position in international comparisons of health-care efficiency. Drug and device corporations use strategies such as making biased inferences, influencing scientists and physicians, marketing rather than informing the public, and lobbying to control their own industry regulations to create market advantage. Successful marketing leads to the increased use of costly profit-making drugs and procedures over cheaper, nonpatented therapies. Because resources are limited, the overuse of costly modalities contributes to expensive health care, which presents a challenge to universal coverage. The free market also fosters the proliferation of industries, such as tobacco, food, and chemicals, which externalize costs to maximize profits, seek to unduly influence research by paying experts and universities, and attempt to control the media and regulatory agencies. Most vulnerable to the cumulative harm of these tactics are children, the poor, the sick, and the least educated.

CONCLUSIONS

The free market can harm health and health care. The corporate obligation to increase profits and ensure a return to shareholders affects public health. Such excesses of capitalism pose formidable challenges to social justice and public health. The recognition of the health risks entailed by corporation-controlled markets has important implications for public policy. Reforms are required to limit the power of corporations.

[Cholesterol controversy: cutoff point of low-density lipoprotein cholesterol level in Guidelines by Japan Atherosclerosis Society]

In 2007, the Japan Atherosclerosis Society published the Guidelines for prevention of atherosclerotic cardiovascular diseases. However, the guidelines have several flaws with regard to the cutoff level of serum low-density lipoprotein cholesterol (LDL-C). First, LDL-C level is used instead of serum total cholesterol (TC) level in the guidelines. In this case, they must show at least some basic data on the relationship between LDL-C level and mortality or morbidity from coronary heart disease (CHD). Second, it was recommended that the LDL-C level be below 140 mg/dL or 3.6 mmol/L (corresponding to a TC level of 220 mg/dL or 5.7 mmol/L, respectively). These levels are unreasonable considering that the TC levels of 240-260 mg/dL are optimal in terms of all-cause mortality for the Japanese population. Third, although there are big differences in mortality and morbidity from CHD between sexes, they discussed the matter without considering these differences. Last but not least, the conflict of interest of the editors of the guidelines has never been disclosed. The Japanese population has a lower CHD mortality and incidence than populations from other industrialized countries despite an increase in serum TC level in the former. In populations with a markedly lower coronary mortality or morbidity such as the Japanese population, it is still important to determine the optimal cutoff level of LDL-C to prevent the development of CHD and other atherosclerotic diseases.

[Questionable documentation of the effect of pregabalin in fibromyalgia]

BACKGROUND

Use of Pregabalin has increased considerably in Norway during the last years. One explanation is prescription to patients with diffuse musculo-skeletal pain. The aim of the article is to clarify the effect of pregabalin in fibromyalgia.

MATERIAL AND METHODS

This article is based on literature identified through searches in Medline and public trial registries.

RESULTS

Six randomized, double-blind clinical trials were identified (three of them in peer-reviewed journals) and Pfizer had initiated and sponsored them all. The three trials published in peer-reviewed journals used a numerical rating scale for pain as the primary endpoint, and all trials reported statistically significant improvements on mean pain scores in relation to placebo. The mean pain reduction was between 9 % and 15 %. Effects on secondary endpoints varied considerably, both within and between the studies. Negative results were seldom mentioned in the abstracts, and secondary endpoints were reported incompletely. All 19 reviews referred to one or more of the clinical trials, and were generally limited to describing main results.

INTERPRETATION

Recommendations for pregabalin in treatment of patients with fibromyalgia are based on rather weak evidence. Until trials independent of industry-funding are published, the role of pregabalin in treatment of fibromyalgia remains unclear.

The financing of drug trials by pharmaceutical companies and its consequences. Part 1: a qualitative, systematic review of the literature on possible influences on the findings, protocols, and quality of drug trials

BACKGROUND

In recent years, a number of studies have shown that clinical drug trials financed by pharmaceutical companies yield favorable results for company products more often than independent trials do. Moreover, pharmaceutical companies have been found to influence drug trials in various ways. This paper provides an overview of the findings of current, systematic studies on this topic.

METHODS

Publications retrieved from a systematic Medline search on this topic from 1 November 2002 to 16 December 2009 were independently evaluated and selected by two of the authors. These publications were supplemented by further ones found in their references sections.

RESULTS

57 publications were included for evaluation in Parts 1 and 2 of this article. Published drug trials that were financed by pharmaceutical companies, or whose authors declared a financial conflict of interest, were found to yield favorable results for the drug manufacturer more frequently than independently financed trials whose authors had no such conflicts. The results were also interpreted favorably more often than in independently financed trials. Furthermore, there was evidence that pharmaceutical companies influenced study protocols in a way that was favorable to themselves. The methodological quality of trials financed by pharmaceutical companies was not found to be any worse than that of trials financed in other ways.

CONCLUSION

Published drug trials that are financed by pharmaceutical companies may present a distorted picture. This cannot be explained by any difference in methodological quality between such trials and trials financed in other ways.

Relationships between authorship contributions and authors' industry financial ties among oncology clinical trials

PURPOSE To test the hypothesis that authors who play key scientific roles in oncology clinical trials, and who therefore have increased influence over the design, analysis, interpretation or reporting of trials, are more likely than those who do not play such roles to have financial ties to industry. METHODS Data were abstracted from all trials (n = 235) of drugs or biologic agents published in the Journal of Clinical Oncology between January 1, 2006 and June 30, 2007. Article-level data included sponsorship, age group (adult v pediatric), phase, single versus multicenter, country (United States v other), and number of authors. Author-level data (n = 2,927) included financial ties (eg, employment, consulting) and performance of key scientific roles (ie, conception/design, analysis/interpretation, or manuscript writing). Associations between performance of key roles and financial ties, adjusting for article-level covariates, were examined using generalized linear mixed models. Results One thousand eight hundred eighty-one authors (64%) reported performing at least one key role, and 842 authors (29%) reported at least one financial tie. Authors who reported performing a key role were more likely than other authors to report financial ties to industry (adjusted odds ratio [OR], 4.3; 99% CI, 3.0 to 6.0; P < .0001). The association was stronger among trials with, compared with those without, industry funding (OR, 5.0 [99% CI, 3.4 to 7.5] v OR, 2.5 [99% CI, 1.3 to 4.8]), but was present regardless of sponsorship. CONCLUSION Authors who perform key roles in the conception and design, analysis, and interpretation, or reporting of oncology clinical trials are more likely than authors who do not perform such roles to have financial ties to industry.

Evidence-based medicine in psychopharmacotherapy: possibilities, problems and limitations

Psychopharmacotherapy should now be regulated in the sense of evidence-based medicine, as is the case in other areas of clinical treatment in medicine. In general this is a meaningful development, which principally will have a positive impact on routine health care in psychiatry. But several related problems should not be ignored. So far consensus on an internationally accepted evidence graduation could not be reached due to several difficulties related to this. For example, focussing on the results of meta-analyses instead of considering relevant single studies results in a decision-making logic which is in conflict with the rationale applied by drug authorities in the licensing process. Another example is the relevance of placebo-controlled trials: if randomized placebo-controlled phase-III studies are prioritized in the evidence grading, the evidence possibly deviates too far from the conditions of routine clinical care due to the special selection of patients in those studies. However, a grading primarily based on active comparator trials could lead to wrong conclusions about efficacy. This concerns especially the so-called "effectiveness" studies and other forms of phase-IV studies with their less restrictive methodological rigidity. Attempts to regulate psychopharmacotherapy in the sense of evidence-based medicine come closer to their limits the more complex the clinical situation and the respective decision-making logic are. Even in times of evidence-based medicine a large part of complex clinical decision-making in psychopharmacotherapy still relies more on clinical experience and a consensus on clinical experience, traditions and belief systems than on results of efficacy oriented phase-III and effectiveness-oriented phase-IV clinical studies.

The alcohol industry and public interest science

AIMS

This report argues that the growing involvement of the alcohol industry in scientific research needs to be acknowledged and addressed. It suggests a set of principles to guide ethical decision-making in the future.

METHODS

We review relevant issues with regard to relationships between the alcohol industry and the international academic community, especially alcohol research scientists. The guiding principles proposed are modelled after expert committee statements, and describe the responsibilities of governmental agencies, the alcohol industry, journal editors and the academic community. These are followed by recommendations designed to inform individuals and institutions about current 'best practices' that are consistent with the principles.

FINDINGS AND CONCLUSIONS

Growing evidence from the tobacco, pharmaceutical and medical fields suggests that financial interests of researchers may compromise their professional judgement and lead to research results that are biased in favour of commercial interests. It is recommended that the integrity of alcohol science is best served if all financial relationships with the alcoholic beverage industry are avoided. In cases where research funding, consulting, writing assignments and other activities are initiated, institutions, individuals and the alcoholic beverage industry itself are urged to follow appropriate guidelines that will increase the transparency and ethicality of such relationships.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users.Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement--a reporting guideline published in 1999--there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions.The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this Explanation and Elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA Statement, this document, and the associated Web site (http://www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users.Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement--a reporting guideline published in 1999--there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions.The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this Explanation and Elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA Statement, this document, and the associated Web site (http://www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarise evidence relating to efficacy and safety of healthcare interventions accurately and reliably. The clarity and transparency of these reports, however, are not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (quality of reporting of meta-analysis) statement-a reporting guideline published in 1999-there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realising these issues, an international group that included experienced authors and methodologists developed PRISMA (preferred reporting items for systematic reviews and meta-analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this explanation and elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA statement, this document, and the associated website (www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

Survey of conflict-of-interest disclosure policies of ophthalmology journals

PURPOSE

To survey the disclosure policy for authors, peer reviewers, and editors in English-language ophthalmology journals.

DESIGN

Cross-sectional survey.

PARTICIPANTS

English-language ophthalmology journals.

METHODS

All indexed English-language ophthalmology journals were identified. The journals' websites were reviewed for published conflict-of-interest disclosure policies for authors, peer reviewers, and editors. In cases where no policy was found, the journal's editor was contacted directly to confirm if a policy existed.

MAIN OUTCOME MEASURES

The existence of conflict-of-interest policy for authors, peer reviewers, and editors.

RESULTS

Forty-two English-language ophthalmology journals were identified. Web-based published conflict-of-interest policies were found for authors in 33 (79%), for peer reviewers in 3 (7%), and for editors in 2 (5%) of the 42 journals. After contacting those journals with no published policies, these numbers increased to 37 (100%) of 37 for authors, 18 (60%) of 30 for peer reviewers, and 10 (33%) of 30 for editors. Seven journals with published disclosure policies for authors, but not for peer reviewers or editors, did not respond to the survey, and a further 5 journals without any published disclosure policy did not respond to the survey. Journals with a higher impact factor were more likely to have a web-based published disclosure policy for peer reviewers and a disclosure policy for editors.

CONCLUSIONS

Most English-language ophthalmology journals have a conflict-of-interest policy for authors; however, they are not publicly available in 21% of journals. Conflict-of-interest policies for peer reviewers and editors are less common and are more likely not to be published compared with those for authors.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Relation of study quality, concordance, take home message, funding, and impact in studies of influenza vaccines: systematic review

OBJECTIVE

To explore the relation between study concordance, take home message, funding, and dissemination of comparative studies assessing the effects of influenza vaccines.

DESIGN

Systematic review without meta-analysis.

DATA EXTRACTION

Search of the Cochrane Library, PubMed, Embase, and the web, without language restriction, for any studies comparing the effects of influenza vaccines against placebo or no intervention. Abstraction and assessment of quality of methods were carried out.

DATA SYNTHESIS

We identified 259 primary studies (274 datasets). Higher quality studies were significantly more likely to show concordance between data presented and conclusions (odds ratio 16.35, 95% confidence interval 4.24 to 63.04) and less likely to favour effectiveness of vaccines (0.04, 0.02 to 0.09). Government funded studies were less likely to have conclusions favouring the vaccines (0.45, 0.26 to 0.90). A higher mean journal impact factor was associated with complete or partial industry funding compared with government or private funding and no funding (differences between means 5.04). Study size was not associated with concordance, content of take home message, funding, and study quality. Higher citation index factor was associated with partial or complete industry funding. This was sensitive to the exclusion from the analysis of studies with undeclared funding.

CONCLUSION

Publication in prestigious journals is associated with partial or total industry funding, and this association is not explained by study quality or size.

Discrepancy between results and abstract conclusions in industry- vs nonindustry-funded studies comparing topical prostaglandins

PURPOSE

To investigate the relationship between industry- vs nonindustry-funded publications comparing the efficacy of topical prostaglandin analogs by evaluating the correspondence between the statistical significance of the publication's main outcome measure and its abstract conclusions.

DESIGN

Retrospective, observational cohort study.

METHODS

English publications comparing the ocular hypotensive efficacy between any or all of latanoprost, travoprost, and bimatoprost were searched from the MEDLINE database. Each article was reviewed by three independent observers and was evaluated for source of funding, study quality, statistically significant main outcome measure, correspondence between results of main outcome measure and abstract conclusion, number of intraocular pressure outcomes compared, and journal impact factor. Funding was determined by published disclosure or, in cases of no documented disclosure, the corresponding author was contacted directly to confirm industry funding. Discrepancies were resolved by consensus. The main outcome measure was correspondence between abstract conclusion and reported statistical significance of the publications' main outcome measure.

RESULTS

Thirty-nine publications were included, of which 29 were industry funded and 10 were nonindustry funded. The published abstract conclusion was not consistent with the results of the main outcome measure in 18 (62%) of 29 of the industry-funded studies compared with zero (0%) of 10 of the nonindustry-funded studies (P = .0006). Twenty-six (90%) of the industry-funded studies had proindustry abstract conclusions.

CONCLUSIONS

Twenty-four percent of the industry-funded publications had a statistically significant main outcome measure; however, 90% of the industry-funded studies had proindustry abstract conclusions. Both readers and reviewers should scrutinize publications carefully to ensure that data support the authors' conclusions.

[Treatment recommendations from the Drug Commission of the German Medical Association]

The clinical practice guidelines of the Drug Commission of the German Medical Association (DCGMA) are intended to provide a solid basis of therapeutic rationality. Being evidence-based and practice-orientated, these guidelines are not supposed to restrict or replace independent and responsible action. The DCGMA board selects the topics with their importance to general practice being a relevant criterion. A multidisciplinary working group comprising DCGMA experts that have no conflict of interest with the pharmaceutical industry is then established. A panel of office-based physicians is involved in the process of establishing consensus. Once the paper is accepted, the respective professional societies are consulted. Finally, the guideline is released by the DCGMA board and distributed via different publications and educational events. DCGMA clinical practice guidelines are developed in consideration of the best available evidence; however, for many questions of pharmacological treatment the evidence remains fragmentary. In addition, there are many points where the results of clinical research, currently often funded by pharmaceutical companies, might not be unbiased.

Diet and nutrition advice from the Cochrane Library: is it useful for the consumers and family physicians?

BACKGROUND

The role of nutrition in public health is well established. This raises the need for reliable and up to date evidence and its ready accessibility for health professionals and consumers.

OBJECTIVES

The principal objectives are to evaluate whether nutrition-related Cochrane Systematic Reviews contain clear guidance on nutritional aspects that may be applicable to individual patient care.

METHODS

We screened and searched the Cochrane reviews of Issue 3, 2007 of the Cochrane Library. The abstracts were assessed to identify nutrition-relevant reviews which are applicable in the consulting room. All irrelevant studies were excluded and a questionnaire was filled in for each review by the consumers and a Nutrition specialist.

RESULTS

The screening and search of the Cochrane Library Issue 3, 2007 retrieved overall 270 reviews. After excluding the irrelevant results, from the remaining reviews, 17 reviews were about the nutrition and feeding of infants, 44 of the reviews were on diet and nutrition and 78 on nutritional supplementations. From the 38 reviews on nutrition, seven did not have clear translation for the consulting room.

CONCLUSIONS

Our study provided an overview of the number of Cochrane reviews on diet and nutrition in Issue 3, 2003 of the Cochrane Library and highlighted the need for more clear and understandable evidence-based information in the field of nutrition.

Industry-supported meta-analyses compared with meta-analyses with non-profit or no support: differences in methodological quality and conclusions

Background

Studies have shown that industry-sponsored meta-analyses of drugs lack scientific rigour and have biased conclusions. However, these studies have been restricted to certain medical specialities. We compared all industry-supported meta-analyses of drug-drug comparisons with those without industry support.

Methods

We searched PubMed for all meta-analyses that compared different drugs or classes of drugs published in 2004. Two authors assessed the meta-analyses and independently extracted data. We used a validated scale for judging the methodological quality and a binary scale for judging conclusions. We divided the meta-analyses according to the type of support in 3 categories: industry-supported, non-profit support or no support, and undeclared support.

Results

We included 39 meta-analyses. Ten had industry support, 18 non-profit or no support, and 11 undeclared support. On a 0–7 scale, the median quality score was 6 for meta-analyses with non-profit or no support and 2.5 for the industry-supported meta-analyses (P < 0.01). Compared with industry-supported meta-analyses, more meta-analyses with non-profit or no support avoided bias in the selection of studies (P = 0.01), more often stated the search methods used to find studies (P = 0.02), searched comprehensively (P < 0.01), reported criteria for assessing the validity of the studies (P = 0.02), used appropriate criteria (P = 0.04), described methods of allocation concealment (P = 0.05), described methods of blinding (P = 0.05), and described excluded patients (P = 0.08) and studies (P = 0.15). Forty percent of the industry-supported meta-analyses recommended the experimental drug without reservations, compared with 22% of the meta-analyses with non-profit or no support (P = 0.57).

In a sensitivity analysis, we contacted the authors of the meta-analyses with undeclared support. Eight who replied that they had not received industry funding were added to those with non-profit or no support, and 3 who did not reply were added to those with industry support. This analysis did not change the results much.

Conclusion

Transparency is essential for readers to make their own judgment about medical interventions guided by the results of meta-analyses. We found that industry-supported meta-analyses are less transparent than meta-analyses with non-profit support or no support.

Evidence-informed evidence-making

The extent to which clinical and public health guidance developed by the National Institute for Health and Clinical Excellence (NICE) can effectively serve the public by improving quality and efficiency across the National Health Service (NHS) and the broader public sector depends largely on the quality and relevance of the available evidence which informs its decisions. There are well-established organizational and procedural links between NICE and academic and professional organizations that undertake evidence synthesis. However, there are fewer means for evidence gaps identified during the development of NICE guidance to lead to the commissioning of new prospective studies. In this paper, we discuss the importance of a publicly funded clinical and public health research agenda that includes new prospective studies aimed at addressing knowledge gaps identified by NICE. We describe the early experience of NICE and the National Institute for Health Research (NIHR) working together to articulate and commission research to inform best practice recommendations. We propose ways in which NICE can collaborate more effectively with research funders to improve the evidence base upon which it bases its recommendations.

Influence of pharmaceutical funding on the conclusions of meta-analyses

Original data are sound, but conclusions should be interpreted with caution