The review states: "Sponsorship of drug and device studies by the manufacturing company leads to more favorable efficacy results and conclusions than sponsorship by other sources." It reports that "industry sponsored drug and device studies more often had efficacy results that were favorable to the sponsors' products" with a risk ratio of 1.27 (95% CI 1.17 to 1.37), and "more often favorable conclusions" with a risk ratio of 1.34 (95% CI 1.19 to 1.51) compared with non-industry sponsored studies. The authors add that their analyses "suggest the existence of an industry bias that cannot be explained by standard 'Risk of bias' assessments."

Industry-sponsored research or author conflicts of interest (COIs) associated with results and conclusions that favor the sponsor are called “funding bias.” Numerous studies have documented that industry-sponsored biomedical and clinical research is more likely to report positive results than research funded by government or non-profit sources. However, identifying funding bias in any particular study is challenging. The presence of an association between funding source and outcome does not necessarily mean that any given industry-sponsored study is biased; high-quality, industry-funded research that reports unfavorable results does exist, and some non-industry-funded studies may also be biased.

This study of randomized controlled trials of biologic therapies in high-impact journals found: "Industry-funded studies were significantly more likely to report a statistically significant positive primary outcome compared to studies without industry funding (85% vs. 67%, χ² = 5.867, p = 0.015)." It also reports that industry-funded trials "were significantly more likely to utilize placebo or no comparator than non-industry-funded trials (78% vs. 49%, χ² = 4.430, p = 0.035)." The authors conclude: "Industry-funded trials investigating biologic therapies are more likely to yield statistically significant positive outcomes and use placebo comparators when compared to non-industry-funded biologic therapy trials in high-impact medical journals."

Summarizing pooled analyses, the authors report: "Industry sponsored studies more often had favorable efficacy results, RR 1.27 (95% CI 1.17 to 1.37) ... and more often favorable conclusions RR 1.34 (95% CI 1.19 to 1.51) compared with non-industry sponsored studies." They add: "We did not find a difference between drug and device studies in the association between sponsorship and conclusions" and state that the results are "consistent with the presence of an industry bias" even though standard risk-of-bias tools did not fully explain it.

This scoping review defines funding bias as occurring "when the design, conduct, or reporting of research is influenced by the source of funding in ways that systematically favor the funder’s interests." It summarizes evidence that "industry-funded studies are more likely to report positive results and pro-industry conclusions" but stresses that this risk can be mitigated: "Policy mechanisms such as mandatory trial registration, disclosure of conflicts of interest, independent data analysis, and restrictions on sponsor control over publication were identified as approaches intended to reduce the risk of funding bias, rather than to prohibit industry funding." The authors emphasize that the focus is on *managing* conflicts of interest, not assuming that all industry-funded research is necessarily biased.

This systematic review of 30 studies reports: "Studies sponsored by pharmaceutical companies were more likely to have outcomes favouring the sponsor than were studies with other sponsors (odds ratio 4.05; 95% confidence interval 2.98 to 5.51; 18 comparisons)." It notes that "research funded by drug companies was less likely to be published than research funded by other sources" and that 13 included investigations "found that clinical trials and meta-analyses sponsored by drug companies favoured the product produced by the funder." The authors state: "Research sponsored by the drug industry was more likely to produce results favouring the product made by the company sponsoring the research than studies funded by other sources," across a wide range of diseases, drugs, and study types.

This systematic review and meta-analysis examined clinical trial funding and investigator conflicts of interest. It found that industry-funded trials were significantly more likely to report positive results compared with non–industry-funded trials. The authors report that financial conflicts of interest of principal investigators and industry sponsorship were each associated with an increased likelihood of positive outcomes, suggesting that commercial ties can bias trial findings in favor of sponsors’ products.

Cochrane explains that conflicts of interest (including industry funding) "can lead to systematic bias in the design, conduct, analysis, and reporting of research" and that "there is evidence that industry sponsorship of drug and device studies is associated with more favourable results and conclusions for the sponsor's products." At the same time, the Handbook cautions that "industry funding alone is not a standard ‘risk of bias’ domain" and that review authors should not automatically rate all industry-funded studies as high risk: instead, each study’s methods and conduct must be evaluated. It recommends transparency and management of conflicts (e.g. declarations of interest, independent oversight) rather than blanket exclusion of industry-sponsored research.

The entry defines industry sponsorship bias as "a tendency for the methods and results of a study to support the interests of the funding organisation" and notes that it is also called funding bias or sponsorship bias. It cites empirical evidence: "Of the 65 trials where the trial was sponsored by the maker of the newer drug, favourable results were reported in 66% of the studies and favourable conclusions drawn in 79% of the cases. Of the 30 studies in which the trial sponsor was the maker of the older drug, only 3 (10%) reported favourable results for the non-sponsored drug." It also summarizes a Cochrane review finding that industry-sponsored research showed treatment benefits "more likely to favour the sponsor’s products (relative risk = 1.27; 95% CI 1.17 to 1.37) and authors’ conclusions were more favourable (relative risk = 1.34; 95% CI 1.19 – 1.51)" than non-industry sponsored research.

This article reports on 114 trials and notes: "Studies sponsored by pharmaceutical companies were more likely to have outcomes favoring the sponsor's product than were studies with other sponsors." The authors state that this association persisted after controlling for selected study characteristics and conclude that their findings "raise the possibility that pharmaceutical industry sponsorship may influence trial outcomes in favor of the sponsor's drug."

Studies reporting the results of industry sponsored clinical trials present a more favorable picture of the effects of drugs and medical devices than those reporting on non-industry sponsored trials, according to a new Cochrane systematic review. The researchers carried out a systematic review of 48 studies on drugs and medical devices. Studies sponsored by industry reported greater benefits and fewer harmful side effects compared to studies that were not sponsored by industry. Papers describing industry sponsored studies presented more favourable overall conclusions, and results and conclusions sections in these papers were less likely to agree. "Our results suggest that industry sponsored drug and medical device studies are more often favourable to the sponsor's products than non-industry sponsored studies," said lead researcher Andreas Lundh of the Nordic Cochrane Centre.

Industry sponsorship is a key source of bias that can affect research at multiple stages. Data from several fields have shown biases in the design, conduct, and publication of industry-sponsored research. These include the selection of comparators and outcomes that increase the chance of showing benefit, selective publication of positive results, and suppression of negative studies. Evidence also suggests that industry sponsorship not only influences the results of individual studies but can shape the overall research agenda by prioritizing questions that are commercially profitable over those that are most important for public health. However, the authors note that the presence of industry funding does not automatically invalidate research; rather, it increases the need for safeguards such as transparency of protocols, independent oversight, and full reporting of all results.

Analyzing 206 nutrition-related articles, this study reports: "Among the 111 interventional studies, those funded entirely by industry were more likely to have conclusions in favor of the sponsor's products (P = 0.037) than were those with other sources of funding." It also finds that "studies about soft drinks funded by industry were more likely to report no association or a negative association with obesity" compared with those funded by other sources, indicating an association between funding source and favorable conclusions outside of pharmaceuticals.

Lisa Bero describes a body of research showing that studies sponsored by pharmaceutical companies are more likely to have outcomes and conclusions that favor the sponsor’s product than studies funded by independent sources. She notes that such bias can arise through choices in study design, selective reporting of outcomes, and publication bias. Bero also emphasizes that bias from industry funding is often "subtle" and "not usually due to overt data falsification," and that some industry-funded studies are well designed and transparently reported. She argues that readers should critically evaluate methods, comparators, and outcome reporting rather than assuming that all industry-sponsored research is either fully trustworthy or entirely biased. The article discusses strategies to reduce funding-related bias, including preregistration of trials, data sharing, and ensuring that investigators, not sponsors, control analysis and publication decisions.

This systematic review states: "Our review shows that pharmaceutical industry funding of studies is associated with pro-industry conclusions." It notes that in most of the included empirical studies, "industry-sponsored research was more likely to have outcomes favouring the sponsor" and it highlights that this association "does not appear to be explained by standard measures of methodological quality," suggesting that other mechanisms, such as choice of comparator or selective reporting, may contribute.

The ORI training module notes that in assessing conflicts of interest, "we need to consider the likelihood of bias as well as the consequences" and that certain financial relationships "may increase the risk that professional judgments or actions regarding a primary interest will be unduly influenced by a secondary interest." It emphasizes that conflicts of interest are *situations* that create risk, not proof that bias has occurred: "The presence of a conflict of interest does not mean that a researcher has behaved in an unethical manner. However, unmanaged conflicts can compromise, or appear to compromise, the integrity of research." The guidance calls for disclosure and management plans, rather than presuming that all research involving conflicts (including industry funding) is biased.

Reviewing studies on environmental and occupational health, the authors note: "Reviews funded by industry were more likely to report conclusions that were favorable to the sponsor's products" compared with reviews funded by non-industry sources. They specifically highlight secondhand smoke research, stating that tobacco industry–funded reviews were far more likely to conclude that passive smoking was not harmful than independently funded reviews, illustrating a strong association between industry sponsorship and favorable conclusions in another domain.

When researchers distort the results or modify conclusions of their study due to pressure of commercial or not-for-profit funders, they engage in questionable research practice. This is called funding or sponsorship bias, also known as the "funding effect." The term was formed in the 1980s when it was discovered that researchers do not always report their results honestly but distort findings to support the aims of the funding sources. It has been shown that industry sponsored studies are more likely to publish positive results than those sponsored by not-for-profit and independent organisations. One of the reasons is that funders may prevent publishing of the manuscript containing unfavourable results or even take legal action against researchers. To prevent funding bias, the International Committee of Medical Journal Editors (ICMJE) requires that research articles include disclosure of sources of support, the role of sponsors in design, data collection, analysis and reporting, and any restrictions on publication, or a statement that the sponsor had no such involvement.

Across medicine and the health sciences, there is a well-established empirical pattern: on average, industry-funded clinical trials and reviews are more likely to report statistically positive results and favorable conclusions about a sponsor’s products than trials funded by non-commercial sources. However, major journals and regulators do publish industry-sponsored trials with neutral or negative findings, and many industry-sponsored studies adhere to high methodological standards and transparent reporting, showing that sponsorship increases the *probability* of favorable outcomes but does not guarantee bias in every individual study.