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Methodology Review

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Industry sponsorship and research outcome

  1. Andreas Lundh1,*,
  2. Sergio Sismondo2,
  3. Joel Lexchin3,
  4. Octavian A Busuioc2,
  5. Lisa Bero4

Editorial Group: Cochrane Methodology Review Group

Published Online: 12 DEC 2012

Assessed as up-to-date: 30 SEP 2010

DOI: 10.1002/14651858.MR000033.pub2


How to Cite

Lundh A, Sismondo S, Lexchin J, Busuioc OA, Bero L. Industry sponsorship and research outcome. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: MR000033. DOI: 10.1002/14651858.MR000033.pub2.

Author Information

  1. 1

    Rigshospitalet, The Nordic Cochrane Centre, Copenhagen, Denmark

  2. 2

    Queen's University, Department of Philosophy, Kingston, Ontario, Canada

  3. 3

    York University, School of Health Policy and Management, Toronto, Ontario, Canada

  4. 4

    University of California San Francisco, Department of Clinical Pharmacy and Institute for Health Policy Studies, San Francisco, California, USA

*Andreas Lundh, The Nordic Cochrane Centre, Rigshospitalet, Blegdamsvej 9, 7811, Copenhagen, DK-2100, Denmark. al@cochrane.dk.

Publication History

  1. Publication Status: Edited (no change to conclusions), comment added to review
  2. Published Online: 12 DEC 2012

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This is not the most recent version of the article. View current version (16 FEB 2017)

 
Characteristics of included studies [ordered by study ID]
Ahmer 2005

MethodsTo study the association between study support and outcome in randomized controlled trials (RCTs) of psychotropic drugs. All RCTs published in Acta Psychiatrica Scandinavica (APS), American Journal of Psychiatry (AJP), Archives of General Psychiatry (AGP) and British Journal of Psychiatry (BJP) from July 1998 to June 2003.


Data188 psychotropic drug RCTs (various comparators).


ComparisonsManufacturer support and no support.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesDatabase and handsearch.

Control for bias?NoSubgroup analysis, but only of journal name.

Alasbali 2009

MethodsTo investigate the relationship between industry vs non-industry 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. Studies published from 1966 to November 2007.


Data39 reports of head-to-head comparisons of topical prostaglandins in ophthalmology (various study designs).


ComparisonsIndustry and non-industry funding.


OutcomesStudy conclusions, study results and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?UnclearNot clear which study designs and whether placebo controlled studies were included, cannot be replicated.

Adequate study inclusion process?UnclearThree assessors for data extraction, but unclear in relation to study inclusion.

Comprehensive search?YesMEDLINE and handsearching.

Control for bias?UnclearNot described.

Als-Nielsen 2003

MethodsTo explore whether the association between funding and conclusions in randomized drug trials reflects treatment effects or adverse events. All randomized trials included in eligible meta-analyses from a random sample of Cochrane reviews obtained in May 2001 (RCTs from 1971 to 2000).


Data370 drug RCTs (mixed comparisons).


ComparisonsFunding from non-profit organizations, not reported, both non-profit and for-profit organizations, and for-profit organizations.


OutcomesStudy conclusions, effect size and methodological quality (generation of randomization sequence, concealment of allocation and double blinding).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesOne assessor screened and two involved in final inclusion.

Comprehensive search?YesIdentification via Cochrane reviews.

Control for bias?YesLogistic regression adjusting for treatment effect, adverse events, and other potentially confounding trial variables (methodological quality, sample size, whether preset sample size was estimated and reached, meta-analysis, year of publication, and journal impact factor). Adjusted for treatment effect and double blinding in final model.

Barden 2006

MethodsTo study if industry sponsored trials yield a better result than trials not sponsored by industry, and if a particular drug would perform better as the test drug in trials funded by its manufacturer and worse as the comparator drug in trials funded by a competitor. RCTs from published systematic reviews in acute pain and migraine (reviews from 1999 to 2004).


Data176 acute pain or migraine drug RCTs (active comparator or placebo controlled).


ComparisonsIndustry versus non-industry and manufacturer versus competitor funding.


OutcomesEffect size and methodological quality (Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesFrom Cochrane reviews, seems more than one assessor was used.

Comprehensive search?YesIdentification via Cochrane reviews.

Control for bias?NoNo control for bias.

Bero 2007

MethodsTo examine the associations between research funding source, study design characteristics aimed at reducing bias, and other factors that potentially influence results and conclusions in randomized controlled trials of statin–drug comparisons. All statin RCTs with active comparators from January 1999 to May 2005.


Data192 statin RCTs (active comparators).


ComparisonsIndustry, none disclosed/no funding and government/private non-profit funding.


OutcomesStudy results, study conclusions, methodological quality (concealment of allocation, blinding and follow-up) and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesTwo or more assessors included studies.

Comprehensive search?YesMEDLINE and references.

Control for bias?YesMultivariate logistic regression analysis. Final model controlled for journal Impact Factor, sample size and blinding.

Bhandari 2004

MethodsTo study the association between industry funding and the statistical significance of results in recently published medical and surgical trials. RCTs from January 1999 to June 2001 in 8 leading surgical journals (Journal of Bone and Joint Surgery [American and British volumes], Clinical Orthopaedics and Related Research, Acta Orthopaedica Scandinavica, Annals of Surgery, American Journal of Surgery, Plastic and Reconstructive Surgery and Journal of Neurosurgery) and 5 medical journals (Lancet, BMJ, JAMA, Annals of Internal Medicine and New England Journal of Medicine).


Data332 RCTs of drug, surgery, and other types of interventions (no description of comparisons).


ComparisonsIndustry-for-profit, not-for-profit and undeclared funding.


OutcomesStudy results and methodological quality (Detsky quality index, 0-21 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearch and MEDLINE used.

Control for bias?YesMultivariate logistic regression with adjustment for sample size, study quality and type of intervention.

Booth 2008

MethodsTo describe trends in methodology and reporting of RCTs, in addition to sponsorship, outcomes, and authors’ interpretation of results. All RCTs of systemic therapy in breast, colorectal cancer, and non-small-cell lung cancer published during three decades (1975 through 2004) in:Journal of Clinical Oncology, Journal of the National Cancer Institute, Cancer Treatment/Chemotherapy Reports, New England Journal of Medicine, Lancet, and JAMA.


Data321 drug RCTs (active comparators and placebo controlled).


ComparisonsFor-profit/mixed, non-profit and not known funding.


OutcomesStudy results, study conclusions and effect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesDatabase and handsearch.

Control for bias?YesMultivariate logistic regression, final model controlled for time to event, effect size and P value.

Bourgeois 2010

MethodsTo describe characteristics of drug trials listed in ClinicalTrials.gov and examine whether the funding source of these trials is associated with favorable published outcomes. Clinical trials registered from 2000 to 2006 and published up to 2010.


Data546 clinical trials of cholesterol-lowering drugs, antidepressants, antipsychotics, proton-pump inhibitors and vasodilators (active or placebo controlled).


ComparisonsIndustry, government and non-profit/non-federal (with or without industry contributions) funding.


OutcomesStudy results.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesTwo assessors independently carried out the literature search and disagreements were resolved by consensus.

Comprehensive search?YesFour databases, trial registries and contact to investigators and companies.

Control for bias?YesPost hoc multivariate logistic regression analysis to assess the association between funding source and trial outcome, while controlling for other trial characteristics (drug class, approval status of indication, study phase, multicenter status, anticipated sample size, age of study population, comparator type, and length of study).

Brown 2006

MethodsTo evaluate the trends in the source of funding for gastrointestinal clinical research during the period from 1992 to 2002–2003; to determine whether the source of study funding predicted the likelihood that a study would publish results that favor the drug or device being tested; and to determine whether differences exist in the methodologic quality of the investigational study methods used in studies funded by private industry versus other sources. Clinical trials published in 4 gastrointestinal journals (Gastroenterology, The American Journal of Gastroenterology, Hepatology, and Gastrointestinal Endoscopy).


Data450 clinical trials of drugs and devices in gastroenterology (active or placebo controlled).


ComparisonsPrivate industry sponsored, federal/state government sponsored, national society/non-profit agency sponsored and not specified.


OutcomesStudy conclusions and methodological quality (Brown score, 0 to 5 point scale multiplied by 100).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearching of journals.

Control for bias?NoNo control for bias.

Buchkowsky 2004

MethodsTo characterize clinical trial funding, reporting, and sources; investigate author-industry affiliation; and describe clinical outcome trends over time. Random papers from January 1981 to December 2000 from Annals of Internal Medicine, BMJ,JAMA,Lancet and New England Journal of Medicine.


Data500 clinical drug trials (drug versus placebo, active comparator or non-drug comparator).


ComparisonsIndustry, mixed, non-industry and not stated funding.


OutcomesStudy conclusions


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearching of journals.

Control for bias?UnclearInvestigates choice of comparators over time, might have assessed other sources of bias.

Chard 2000

MethodsTo assess the published research base for interventions for osteoarthritis of the knee, and to identify areas in need of further research. Studies from 1950 to 1998.


Data930 studies of different interventions (various study designs with various comparators).


ComparisonsCommercial, government and not stated funding.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoOne assessor on all studies and one on 10% sample, but only 87% agreement indicating two needed for all studies.

Comprehensive search?YesMEDLINE, EMBASE, BIDS, The Cochrane Library, previous reviews and experts contacted.

Control for bias?NoNo control for bias.

Cho 1996

MethodsTo compare the quality, relevance, and structure of drug studies published in symposium proceedings that are sponsored by drug companies with 1) articles from symposia with other sponsors and 2) articles in the peer reviewed parent journals of symposium proceedings; and to study the relation between drug company sponsorship and study outcome. Random selection of symposia from 625 symposia that had been identified for a previous study.


Data127 drug studies (various study designs with various comparators).


ComparisonsDrug company support and no support.


OutcomesStudy conclusions and methodological quality (Cho scale 0-1 point).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?UnclearNot clear enough to replicate how symposia were chosen and how matching papers were chosen.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesComprehensive search within their own database.

Control for bias?YesSubgroup analysis of study design.

Clifford 2002

MethodsTo examine the relationship between funding source, trial outcome and reporting quality;100 RCTs from Annals of Internal Medicine, BMJ, JAMA, Lancet, New England Journal of Medicine. From January 1999 to October 2000 with 20 RCTs/journal.


Data100 drug RCTs (various comparators).


ComparisonsEntirely industry, entirely not-for-profit, mixed and not reported funding.


OutcomesStudy results, methodological quality (Jadad score, 0-5 point scale and concealment of allocation).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearching of journals.

Control for bias?NoNo evidence of risk of bias assessment.

Crocetti 2010

MethodsTo assess the risk of bias among pediatric RCTs reported in 8 high-impact journals (5 pediatric and 3 general medical) from July 2007 to June 2008.


Data146 pediatric drug, behavioral/educational and nutritional RCTs (various comparators)


ComparisonsGovernment, industry, internal hospital grant, multiple sources, none and private foundation funding.


OutcomesMethodological quality (sequence generation; allocation concealment; masking of participants, personnel, and outcome assessors; incomplete outcome data reporting; selective outcome reporting; and other sources of bias).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE search of selected journals.

Control for bias?YesMultivariate logistic regression to test for an association between the presence of a high risk of bias according to domain and the independent variables of funding source, intervention type, author number, and trial registration status.

Davidson 1986

MethodsAn analysis of the results of clinical trials according to funding source. Clinical trials from 1984 in New England Journal of Medicine, Annals of Internal Medicine,the American Journal of Medicine,Archives of Internal Medicine, and the Lancet.


Data107 drug and non-drug clinical trials (various comparators).


ComparisonsPharmaceutical support and general support.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoSingle assessor.

Comprehensive search?YesJournals handsearched.

Control for bias?NoControl for bias seems unlikely to have been done.

Davis 2008

MethodsThe influence of several potentially biasing factors (e.g. industry support, extrapyramidal side effects) on efficacy of studies comparing second-generation antipsychotic with first-generation drugs. Dataset from previously published meta-analysis (search from 1953 to 2002).


Data124 RCTs of second-generation antipsychotics versus first-generation antipsychotics.


ComparisonsIndustry and non-industry funding.


OutcomesEffect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesComprehensive database search including search for unpublished data.

Control for bias?UnclearCarried out various sensitivity analysis, but not clear whether they assessed bias in relation to funding and effect size.

Djulbegovic 2000

MethodsTo evaluate whether the uncertainty principle was upheld, comparison of the number of studies favoring experimental treatments over standard ones according to the source of funding. All RCTs for multiple myeloma from 1996 to 1998.


Data136 multiple myeloma drug RCTs (various comparators).


ComparisonsCommercial and public funding.


OutcomesStudy conclusions and methodological quality (Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoSeems only one author involved in study inclusion.

Comprehensive search?YesUsing the Cochrane search strategy to identify trials.

Control for bias?YesControlled for types of comparator (active versus placebo/no treatment).

Etter 2007

MethodsTo assess whether source of funding affected the results of trials of nicotine replacement therapy for smoking cessation. RCTs from 1979 to 2003 identified from Cochrane review.


Data105 RCTs of nicotine replacement therapy (gum or patch versus placebo or no treatment).


ComparisonsIndustry/mixed and non-industry/not acknowledged funding.


OutcomesStudy results and effect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesFrom Cochrane review, seems more than one assessors was used.

Comprehensive search?YesIdentification via Cochrane review.

Control for bias?YesMultivariate logistic regression with adjustment for sample size.

Finucane 2004

MethodsTo evaluate the association between funding and findings of pharmaceutical research presented at an annual meeting of a clinically oriented US medical professional society.


Data48 presentations of drug studies (observational studies, RCTs and other study designs).


ComparisonsIndustry supported and not industry supported.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?UnclearUnclear what "any abstract that reported results about effectiveness or safety of drugs" means. Not clear which study designs and whether reviews were included.

Adequate study inclusion process?YesSeems likely that two assessors were used.

Comprehensive search?YesComprehensive search within conference.

Control for bias?YesSubgroup analysis of study design.

Freemantle 2000

MethodsTo assess whether specific pharmacological characteristics of alternative antidepressants resulted in altered efficacy compared to that of selective serotonin reuptake inhibitors (SSRI) in the treatment of major depression. All RCTs of SSRI versus alternative antidepressants (search from 1966 to 1997).


Data105 SSRI versus alternative antidepressant RCTs.


ComparisonsSponsor and not sponsor.


OutcomesEffect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, EMBASE, references and reviews.

Control for bias?NoNo assessment of bias in relation to funding and effect size.

Gartlehner 2010

MethodsThe objective of this study was to determine the effect of industry bias in a systematically reviewed sample of head-to-head trials. Trials of SSRI head-to-head comparisons from 1993 to 2005.


Data29 SSRI RCTs of head-to-head comparisons.


ComparisonsSponsor and not sponsor.


OutcomesStudy results and effect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesTwo assessors included studies.

Comprehensive search?YesMEDLINE, EMBASE, The Cochrane Library, the International Pharmaceutical Abstracts database, references and reviews and letters to the editor. In addition, the Center for Drug Evaluation and Research database to identify unpublished research submitted to the US Food and Drug Administration (FDA).

Control for bias?YesSensitivity analysis based on definition of funding.

Halpern 2005

MethodsTo determine whether there is a difference in average statistical power between pharmacoepidemiologic studies of anti-retroviral adverse drug effects (ADEs) sponsored by for-profit versus non-profit organizations (drugs approved from 1987 to 1999 and published until 2002).


Data48 pharmacoepidemiological studies of adverse effects of ani-retroviral drugs.


ComparisonsNon-profit, for-profit, charity/institution, none or unable to determine funding.


OutcomesStudy results (harms).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoOne assessor only.

Comprehensive search?YesMEDLINE, EMBASE and reference lists.

Control for bias?NoNo control for bias.

Heres 2006

MethodsTo review the results of head-to-head studies of second-generation antipsychotics funded by pharmaceutical companies to determine if a relationship exists between the sponsor of the trial and the drug favored in the study’s overall outcome. All head-to-head trials of second-generation antipsychotics from 1997 to 2005.


Data42 head-to-head RCTs of second-generation antipsychotics.


ComparisonsIndustry only (sponsor of test drug or comparator).


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?NoMEDLINE and screen of selected conference proceedings. Sample of conference proceedings limited to 1999-2004, which may introduce bias due to differences in approval dates for the different drugs.

Control for bias?YesSensitivity analysis of peer-reviewed trials only.

Jefferson 2009

MethodsTo explore the relation between study concordance, take home message, funding, and dissemination of comparative studies assessing the effects of influenza vaccines. Studies of various designs from 1961 to 2006.


Data274 studies of influenza vaccine versus placebo/no treatment.


ComparisonsGovernment/private/unfunded, industry/mixed and not stated funding.


OutcomesStudy conclusions, methodological quality (Cochrane risk of bias) and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesTwo assessors included studies.

Comprehensive search?YesMEDLINE, EMBASE, The Cochrane Library, web, and likely references and previous reviews since it is based on Cochrane reviews.

Control for bias?YesSensitivity analysis based on definition of funding and regression analysis of various factors.

Jones 2010

MethodsTo compare the quality of publicly or privately funded randomized controlled trials. Trials included in Cochrane reviews on hypertension and preterm labour.


Data105 drug trials (mixed comparisons).


ComparisonsCommercial, mixed and non-commercial.


OutcomesMethodological quality (selection bias, performance bias, detection bias and attrition).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesBased on searches from Cochrane reviews.

Control for bias?NoNo control for bias.

Kelly 2006

MethodsTo investigate the relationship between industry support and study outcome in the general psychiatric literature. Clinical studies from 1992 and 2002 in American Journal of Psychiatry, Archives of General Psychiatry, and Journal of Clinical Psychopharmacology.


Data301 psychiatric drug studies (mixed comparisons).


ComparisonsNon-industry and industry (sponsor of test drug or comparator) funding.


OutcomesStudy results, study conclusions and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesSample of journals.

Control for bias?YesExplanatory analysis of various mediating variables.

Kemmeren 2001

MethodsTo evaluate quantitatively articles that compared effects of second- and third-generation oral contraceptives on risk of venous thrombosis. Cohort and case control studies from 1995 to 2000.


Data12 cohort and case control studies of second- versus third-generation oral contraceptives.


ComparisonsIndustry and non-industry funding.


OutcomesStudy results and effect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, reviews, relevant papers and experts.

Control for bias?NoMultiple regression used, but not for the association between funding and results or effect size.

Kjaergard 2002

MethodsTo assess the association between competing interests and authors' conclusions. RCTs published in BMJ 1997 to 2001.


Data159 RCTs of mixed interventions (various comparators).


ComparisonsProfit, non-profit, non-profit and profit, non-profit and free drug, free drug only and no funding/not stated.


OutcomesStudy conclusions and methodological quality (sequence generation, concealment of allocation and blinding).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoOnly one assessor included studies.

Comprehensive search?YesMEDLINE journal search.

Control for bias?YesRegression analysis for potential confounders.

Liss 2006

MethodsTo determine whether drug studies in the pulmonary/allergy literature also demonstrate a publication bias towards more favorable results when a pharmaceutical company funds the study. Primary research studies of drug interventions published in Allergy, American Journal of Respiratory and Critical Care Medicine, Annals of Allergy Asthma and Immunology, Chest, European Respiratory Journal, Journal of Allergy and Clinical Immunology, Respiratory Medicine, and Thorax in 2002 to 2003.


DataStudies of nasal or oral inhaled corticosteroids, long- or short-acting bronchodilators, and leukotriene receptor antagonists (various designs and comparisons).


ComparisonsPharmaceutically and not pharmaceutically funded.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoOnly one assessor included studies.

Comprehensive search?YesHandsearch of journals indirectly described.

Control for bias?NoNo control for bias.

Lubowitz 2007

MethodsTo compare outcomes (and levels of evidence) between published Autologous Chondrocyte Implantation outcome studies that were commercially funded and studies that were not commercially funded. Clinical studies from 1994 to 2005.


Data23 studies of chondrocyte implantation (various designs and comparisons).


ComparisonsCommercially funded and not commercially funded.


OutcomesEffect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?NoMEDLINE only, time period not stated and few search terms used.

Control for bias?NoNo control for bias.

Lynch 2007

MethodsTo test the following hypotheses regarding orthopedic manuscripts submitted for review: (1) non-scientific variables, including receipt of commercial funding, affect the likelihood that a peer-reviewed submission will conclude with a report of a positive study outcome, and (2) positive outcomes and other, non-scientific variables are associated with acceptance for publication. Cohort of manuscripts submitted involving original research on the subject of adult hip or knee reconstruction to The Journal of Bone and Joint Surgery (American Volume) between January 2004 and June 2005.


Data209 studies of knee or hip surgery (various designs, interventions and comparisons).


ComparisonsCommercial, non-funded and noncommercial/philanthropic funding.


OutcomesStudy conclusions and methodological quality (Sackett scale, 0 to 100%).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesSample of papers via journal submission system.

Control for bias?NoNo control for bias.

Momeni 2009

MethodsTo investigate if plastic surgical trials with industry-funding are more likely to be associated with statistically significant pro-industry findings. Trials in 4 plastic surgery journals (Plastic and Reconstructive Surgery, British Journal of Plastic Surgery, Annals of Plastic Surgery, and Aesthetic Plastic Surgery) from 1990 to 2005.


Data346 RCTs and controlled clinical trials (various designs, interventions and comparisons).


ComparisonsIndustry, public, university and not specified funding.


OutcomesStudy results.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearch of journals.

Control for bias?NoNo control for bias.

Moncrieff 2003

MethodsTo re-evaluate the evidence comparing clozapine with conventional antipsychotics and to investigate sources of heterogeneity. Trials from 1988 to 2001.


Data9 RCTs of clozapine versus conventional antipsychotics.


ComparisonsIndustry, other and not declared funding.


OutcomesStudy results and effect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?NoOnly one assessor included studies.

Comprehensive search?YesMEDLINE, EMBASE and Cochrane review.

Control for bias?NoUnivariate controlled for various predictors in relation to effect size only.

Montgomery 2004

MethodsTo analyze RCTs of second-generation antipsychotics in schizophrenia with respect to funding source (industry versus non-industry funding). RCTs from 1974 to 2002.


Data86 RCTs of 2nd generation antipsychotics versus other types (various comparisons).


ComparisonsIndustry and non-industry.


OutcomesStudy conclusions and methodological quality (Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, PsychInfo and references.

Control for bias?NoNo control for bias.

Nieto 2007

MethodsTo evaluate differences between studies funded by the pharmaceutical manufacturer of the drug and those with no pharmaceutical funding regarding the findings and interpretation of adverse effects of inhaled corticosteroids. Studies from 1993 to 2002.


Data504 studies of inhaled corticosteroids (various study designs with various comparators).


ComparisonsPharmaceutical funded and not pharmaceutical funded.


OutcomesStudy results (harms), study conclusions (harms) and concordance between study results and conclusions (harms).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesSample of journals were identified by MEDLINE.

Control for bias?YesControlled for confounders using multivariate model.

Pengel 2009

MethodsTo examine the quality of reporting of RCTs in solid organ transplantation that were published 2004 to 2006.


Data332 trials in solid organ transplantation (mixed interventions and comparisons).


ComparisonsCommercial, nonprofit, mixed, no funding and not described.


OutcomesMethodological quality (concealment of allocation and Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, EMBASE and The Cochrane Library.

Control for bias?NoNo control for bias.

Peppercorn 2007

MethodsTo evaluate the correlations between pharmaceutical company involvement, study design, and study outcome and to explore changes in these areas over time. Breast cancer trials of medical therapies that were published in the years 1993, 1998, and 2003 in 10 select English-language medical journals.


Data140 breast cancer drug trials (single arm studies and RCTs).


ComparisonsPharmaceutical studies versus non-pharmaceutical studies.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearch and MEDLINE used.

Control for bias?NoOnly assessment of differences in study design in relation to funding.

Perlis 2005a

MethodsThe purpose was to determine the extent and impact of industry sponsorship conflicts of interest in dermatology research. Drug trials from Journal of Investigative Dermatology, Archives of Dermatology, British Journal of Dermatology, and Journal of the American Academy of Dermatology from 2000 to 2003.


Data179 RCTs of dermatological drugs (various comparators).


ComparisonsIndustry and non-industry funding.


OutcomesStudy conclusions and methodological quality (blinding and Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesSample of journals.

Control for bias?YesMultivariate regression analysis adjusted for conflict of interest, Jadad score, and sample size.

Perlis 2005b

MethodsTo study the extent and implications of industry sponsorship and financial conflicts of interest in psychiatric trials. Drug trials from the American Journal of Psychiatry, Archives of General Psychiatry, Journal of Clinical Psychiatry, andJournal of Clinical Psychopharmacology from 2001 to 2003.


Data397 psychiatric clinical drug trials (various comparators).


ComparisonsIndustry and non-industry funding.


OutcomesStudy results.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearNot sure if 3 assessors extracting data were involved in including studies.

Comprehensive search?YesMEDLINE and handsearch of journals.

Control for bias?YesLogistic regression adjusted for confounders.

Popelut 2010

MethodsTo examine financial sponsorship of dental implant trials, and to evaluate whether research funding sources affects the annual failure rate. Clinical trials from 1988 to 2005.


Data41 clinical trials of dental implants (single arm and active control).


ComparisonsIndustry, non-industry and unknown funding.


OutcomesEffect size.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?NoInclusion criteria reported, but not possible to decipher and seems subjective.

Adequate study inclusion process?YesTwo assessors included studies.

Comprehensive search?YesMEDLINE and handsearch.

Control for bias?YesControlled for confounders using multivariate analysis.

Rasmussen 2009

MethodsTo compare the prevalence of favorable results and conclusions among published reports of registered and unregistered RCTs of new oncology drugs. Cohort of trials from 25 drugs granted first-time Food and Drug Administration (FDA) approval for oncology indications in 2000 to 2005 and published in 1996 to 2008.


Data137 RCTs of oncology drugs (placebo or active control).


ComparisonsIndustry sponsor and other funding.


OutcomesStudy results, study conclusions, methodological quality (blinding) and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE and The Cochrane Library.

Control for bias?YesLogistic regression adjusted for confounders.

Rattinger 2009

MethodsTo examine the association between research funding source, study design characteristics aimed at reducing bias, and other factors with the results and conclusions of RCTs of thiazolidinediones compared to other oral hypoglycemic agents (search 1996 to 2006).


Data61 RCTs of thiazolidinediones (active or placebo control).


ComparisonsTest drug company, other drug company, all others and not declared funding.


OutcomesStudy results, study conclusions, methodological quality (sequence generation and allocation concealment, blinding and follow-up) and concordance between study results and conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, The Cochrane Library, references and reviews.

Control for bias?YesIntended multivariate analysis, but due to few associations only univariate performed.

Ridker 2006

MethodsTo determine in contemporary randomized cardiovascular trials the association between funding source and the likelihood of reporting positive findings. Cardiovascular RCTs published in JAMA, Lancet, and the New England Journal of Medicine in 2000 to 2005.


Data349 RCTs (mixed interventions and comparators).


ComparisonsFor profit, mixed and not for profit funding.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesSample of journals identified via MEDLINE.

Control for bias?NoNo control for bias.

Rios 2008

MethodsTo assess the reporting quality of RCTs in general endocrinology and to identify predictors for better reporting quality. RCTs published in the Journal of Clinical Endocrinology and Metabolism, Clinical Endocrinology, and the European Journal of Endocrinology in 2005 or 2006.


Data89 endocrinology drug RCTs (various comparators).


ComparisonsIndustry, mixed, non-industry and not stated funding.


OutcomesMethodological quality (allocation concealment and blinding).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?YesTwo assessors included studies.

Comprehensive search?YesHandsearch of journals.

Control for bias?YesControlled for confounders using multivariate analysis.

Rochon 1994

MethodsTo study the relation between reported drug performance in published trials and support of the trials by the manufacturer of the drug under evaluation. All non-steroidal anti-inflammatory (NSAID) RCTs from September 1987 to May 1990.


Data56 NSAID RCTs (placebo and head-to-head comparisons).


ComparisonsManufacturer associated only.


OutcomesStudy results (efficacy and harms), study conclusions (efficacy and harms) and methodological quality (Chalmers' scale, 0-100 points).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE searched.

Control for bias?NoControl for bias seems unlikely to have been done.

Tulikangas 2006

MethodsTo determine if there is a significant difference in outcomes of clinical trials funded by industry or not of antimuscarinic medications used to treat overactive bladder symptoms and detrusor overactivity. RCTs from 1980 to 2002.


Data24 RCTs of antimuscarinic drugs (various comparators).


ComparisonsIndustry funded and public funded.


OutcomesStudy results.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE and references.

Control for bias?NoNo control for bias.

Tungaraza 2007

MethodsTo compare drug trials reported in three major psychiatric journals to investigate whether treatments are more likely to report favorable outcomes when they are funded by the pharmaceutical industry. Studies published in the British Journal of Psychiatry, American Journal of Psychiatry and Archives of General Psychiatry from 2000 to 2004.


Data198 psychiatric drug trials (various designs and comparators).


ComparisonsIndustry sponsored, industry authored and independent.


OutcomesStudy conclusions.


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesHandsearch of journals.

Control for bias?NoNo control for bias.

Vlad 2007

MethodsTo identify factors that explain heterogeneity in trials of glucosamine. RCTs of glucosamine from 1980 to 2006.


Data15 RCTs of glucosamine versus placebo for osteoarthritis.


ComparisonsIndustry funding, industry participation, industry author and independent.


OutcomesStudy results, effect size and methodological quality (allocation concealment and Jadad score, 0-5 point scale).


Notes


Risk of bias

ItemAuthors' judgementDescription

Adequate selection criteria?YesObjective criteria used.

Adequate study inclusion process?UnclearDoes not describe number of assessors.

Comprehensive search?YesMEDLINE, The Cochrane Library, conference abstracts, references and reviews.

Control for bias?YesExploration of heterogeneity.

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Chowers 2009No relevant outcomes

Conen 2008No relevant outcomes

Cunningham 2007No separate drug or device data

Friedman 2004Conflicts of interest, not funding

Glick 2006No relevant outcomes

Hall 2007No relevant outcomes

Hill 2007No relevant outcomes (not methodological quality, but reporting quality)

Jagsi 2009No separate drug or device data

Khan 2008No separate drug or device data

Kjaergard 1999No separate drug or device data

Krzyzanowska 2003No relevant outcomes

Kulier 2004No quantitative data

Kulkarni 2007No relevant outcomes

Lai 2006No separate drug or device data

Leopold 2003No separate drug or device data

Leucht 2009aNo relevant outcomes

Leucht 2009bNo relevant outcomes

McLennan 2008No relevant outcomes

Montori 2005No relevant outcomes

Nkansah 2009Calcium supplementation, not a drug

Okike 2007Conflicts of interest, not funding

Okike 2008No relevant outcomes

Procyshyn 2004No relevant data for non-industry studies

Roach 2008No separate drug or device data

Sanossian 2006No relevant outcomes

Shah 2005No separate drug or device data

Thomas 2008No relevant outcomes (not methodological quality, but reporting quality)

Watanabe 2010No relevant outcomes

Yao 2007No separate drug or device data

Yaphe 2001No separate drug or device data

 
Comparison 1. Results: Industry sponsored versus non-industry sponsored studies

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable efficacy results141588Risk Ratio (M-H, Fixed, 95% CI)1.32 [1.21, 1.44]

 2 Number of studies with favorable harms results3561Risk Ratio (M-H, Fixed, 95% CI)1.87 [1.54, 2.27]

 
Comparison 2. Results: Industry sponsorship by test treatment company versus sponsorship by comparator treatment company

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable test treatment efficacy results2131Risk Ratio (M-H, Fixed, 95% CI)4.64 [2.08, 10.32]

 
Comparison 3. Conclusions: industry sponsored versus non-industry sponsored studies

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable conclusions213941Risk Ratio (IV, Random, 95% CI)1.31 [1.20, 1.44]

 
Comparison 4. Conclusions: Industry sponsorship by test treatment company versus sponsorship by comparator treatment company

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable test treatment conclusions3154Risk Ratio (M-H, Fixed, 95% CI)5.90 [2.79, 12.49]

 
Comparison 5. Risk of bias: industry sponsored versus non-industry sponsored studies

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with low risk of bias from sequence generation3487Risk Ratio (IV, Random, 95% CI)0.85 [0.52, 1.41]

 2 Number of studies with low risk of bias from concealment of allocation101311Risk Ratio (IV, Random, 95% CI)1.09 [0.86, 1.38]

 3 Number of studies with low risk of bias from blinding91216Risk Ratio (IV, Random, 95% CI)1.32 [1.05, 1.65]

 4 Number of studies with low risk of bias from loss to follow-up2118Risk Ratio (M-H, Fixed, 95% CI)0.98 [0.84, 1.16]

 
Comparison 6. Concordance between study results and conclusions: industry sponsored versus non-industry sponsored studies

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with concordant study results and conclusions5667Risk Ratio (IV, Random, 95% CI)0.84 [0.70, 1.01]

 
Comparison 7. Subgroup analysis

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable efficacy results141588Risk Ratio (M-H, Fixed, 95% CI)1.32 [1.21, 1.44]

    1.1 High risk of bias
11962Risk Ratio (M-H, Fixed, 95% CI)1.19 [1.06, 1.33]

    1.2 Low risk of bias
3626Risk Ratio (M-H, Fixed, 95% CI)1.53 [1.32, 1.78]

 2 Number of studies with favorable conclusions213941Risk Ratio (IV, Random, 95% CI)1.31 [1.20, 1.44]

    2.1 High risk of bias
173062Risk Ratio (IV, Random, 95% CI)1.26 [1.14, 1.39]

    2.2 Low risk of bias
4879Risk Ratio (IV, Random, 95% CI)1.54 [1.24, 1.91]

 3 Number of studies with favorable conclusions213941Risk Ratio (IV, Random, 95% CI)1.30 [1.18, 1.42]

    3.1 Drug studies
213821Risk Ratio (IV, Random, 95% CI)1.31 [1.19, 1.44]

    3.2 Device studies
2120Risk Ratio (IV, Random, 95% CI)1.09 [0.82, 1.45]

 4 Number of studies with favorable efficacy results141588Risk Ratio (M-H, Fixed, 95% CI)1.32 [1.21, 1.44]

    4.1 Specific treatments or diseases
121143Risk Ratio (M-H, Fixed, 95% CI)1.28 [1.15, 1.43]

    4.2 Mixed domain
2445Risk Ratio (M-H, Fixed, 95% CI)1.41 [1.19, 1.66]

 5 Number of studies with favorable conclusions213941Risk Ratio (IV, Random, 95% CI)1.31 [1.20, 1.44]

    5.1 Specific treatments or diseases
162774Risk Ratio (IV, Random, 95% CI)1.34 [1.19, 1.51]

    5.2 Mixed study domain
51167Risk Ratio (IV, Random, 95% CI)1.26 [1.08, 1.47]

 
Comparison 8. Sensitivity analysis

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Number of studies with favorable efficacy results, sponsorship recoded5517Risk Ratio (M-H, Fixed, 95% CI)1.50 [1.27, 1.76]

 2 Number of studies with favorable conclusions, sponsorship recoded7951Risk Ratio (IV, Random, 95% CI)1.26 [1.06, 1.50]

 3 Number of studies with low risk of bias from sequence generation, sponsorship recoded2249Risk Ratio (M-H, Fixed, 95% CI)1.05 [0.77, 1.44]

 4 Number of studies with low risk of bias from concealment of allocation, sponsorship recoded7663Risk Ratio (M-H, Fixed, 95% CI)1.17 [0.90, 1.52]

 5 Number of studies with low risk of bias from blinding, sponsorship recoded5425Risk Ratio (M-H, Fixed, 95% CI)1.54 [1.23, 1.94]

 6 Number of studies with favorable efficacy results, analysis adjusted for confounders2Odds Ratio (Fixed, 95% CI)3.86 [1.93, 7.70]

 7 Number of studies with favorable conclusions, analysis adjusted for confounders3Odds Ratio (Fixed, 95% CI)4.15 [2.40, 7.19]

 8 Number of studies with favorable efficacy results, random-effects model141588Risk Ratio (IV, Random, 95% CI)1.26 [1.12, 1.41]

 9 Number of studies with favorable harms results, random-effects model3561Risk Ratio (IV, Random, 95% CI)1.87 [1.54, 2.27]

 10 Number of studies with favorable test treatment efficacy results, random-effects model2131Risk Ratio (IV, Random, 95% CI)3.88 [1.32, 11.41]

 11 Number of studies with favorable test treatment conclusions, random-effects model3154Risk Ratio (IV, Random, 95% CI)5.92 [2.80, 12.54]

 12 Number of studies with low risk of bias from loss to follow-up, random-effects model2118Risk Ratio (IV, Random, 95% CI)0.99 [0.84, 1.15]