Do Conflicts of Interests Imply Bias?

According to Elsevier, a conflict of interest is “When an investigator, author, editor, or reviewer has a financial/personal interest or belief that could affect his/her objectivity, or inappropriately influence his/her actions”. This means that there are both financial and non-financial conflicts of interest (Marcovitch, et al., 2010)

As we have discussed in the section above, we can make arguments for why industry funding matters, and why not. If we want to find out whether a conflict of interest matters, we have to be rigorous and not only analyze the study in question, but also the background of the researchers.

Factors that increase risk of bias

There are several situations where scientists are more likely to be biased. Here are some things to look out for.

Undisclosed conflicts of interest

“Everyone has competing interests; financial or private, or both. The main problem with competing interests is nondisclosure [5]. As with all competing interests, it is not possible to reliably judge our own biases. Instead, declaring them allows others to make informed judgments about whether the competing interests are relevant or not.” - PLoS Medicine, 2008

“Undeclared financial conflicts may seriously undermine the credibility of the journal, the authors, and the science itself.” - Elsevier

There isn't anything wrong in having competing interests. They may be near universal in medicine. Most doctors have had their lunch bought for them by a pharmaceutical company and write their prescriptions with pens provided by the industry. Many have been flown to very agreeable locations by the companies to listen to speakers, staying—at the companies' expense—at the best hotels. The problem with conflicts of interest is not declaring them. - Smith, 2002

Many conflicts of interest

This is when researcher(s) have multiple COIs. For example, they can be working for a company, sell books, promote products, provide consulting services, and more.

Selective data presentation and statistical analysis

Scientific data is typically collected and presented in numbers. Numbers may seem objective, but they can be manipulated to tell any story you would like. This is called data torturing (Mills, 1993).

“If you torture the data long enough, it will confess to anything” - Ronald Coase

Scientists can selectively choose, interpret, and present data (Mills, 1993). This is typically done in the conclusion, discussion, or the abstract of a study. This involves hiding or ignoring data that is “unwanted” and focusing on the data that supports the researcher’s conclusion.

“This sort of ‘within-study publication bias’ is usually known as outcome reporting bias or selective reporting bias, and may be one of the most substantial biases affecting results from individual studies (Chan 2005).” - Cochrane

This is why good data reporting and transparency is crucial. It’s also important that scientists follow the original statistical analysis plan submitted with the registration of the trial.

Poor study design

Researchers can design a study with a methodology that favors a desired outcome.

A typical example in the keto literature is to have the keto group eat more protein than control.

Protein improves satiety, helps build muscle, and slightly increases the Thermic Effect of Food (energy expenditure). Thus, it is easier to improve body composition on a high protein diet.

Ignoring alternative hypotheses

This occurs when researchers do not critically reflect on their claims, opinions, or products.

I.e. only presenting data supporting his or her conclusion.

Clustering

Clustering is when scientists work together over multiple projects. (Example: Décombaz et al., 2003).

Direct links to companies

Researchers directly working for a company with their own lab, only doing research on their product. Especially if they are not affiliated with a university.

Factors that decrease risk of bias

Trial registration

“Trial registration is the practice of publishing the methodology of clinical trials before they begin. This reduces problems from publication bias and selective reporting (such as choosing the methodology after the results are known)” - Wikipedia

Studies can be registered at Clinicaltrials.gov

Disclosure of conflicts of interest

All relevant COIs and funding sources are disclosed. This shows honesty and transparency, which are important values.

Solid data reporting and interpretation

Solid data reporting (i.e. reporting objective values, all relevant data shown). Being fair and balanced when writing the abstract and conclusions.

It is crucial to note that data can be gathered, interpreted, analyzed, and presented in many different ways. Minute changes in data analysis can completely change how it is interpreted.

I.e. doing significance tests for percentage changes rather than absolute values. Reporting performance per kg body weight, so that a decrease in bw means an increase in relative performance.

Study methodology

Solid study methodology that does not favor one group over the other. I.e. proper randomization, representativeness, sufficient study power, and more.

Independence of trial

Those that fund a study should not play a role in designing, analyzing or publishing the research. Some companies have their own labs where they actively design their own trials and study methodologies.

Should scientists always disclose their conflicts of interest?

A recent viewpoint was published discussing disclosure in nutrition research (Ioannidis & Trepanowski, 2017). The main idea was that authors should disclose all types of opinions and conflicts of interest (financial and nonfinancial). It is important for the health and fitness field to disclose conflicts of interests in books and other content since it can greatly influence a large number of people who are unaware of how to interpret the research themselves.

Read Quote

“ (...) it is important for nutrition researchers to disclose their advocacy or activist work as well as their dietary preferences if any are relevant to what is presented and discussed in their articles. This is even more important for dietary preferences that are specific, circumscribed, and adhered to strongly. For example, readers should know if an author is strongly adherent to a vegan diet, the Atkins diet, a gluten-free diet, a high animal protein diet, specific brands of supplements, and so forth if these dietary choices are discussed in an article . The types of articles in which relevant disclosure should be expected include original research, reviews, and opinion pieces (such as editorials). Such disclosure should not be seen as an admission of lack of integrity. To the contrary, disclosure strengthens the perceived integrity of the author .”

Further Reading

All of the resources below are free full texts, and are not hidden behind a paywall.