A study that made recent headlines about a possible link between excessive cellphone use and bone spurs in the skull contained significant flaws, according to several reports.

One concern, reported Tuesday in The Washington Post, is that one of the lead authors, a chiropractor named David Shahar, of the University of the Sunshine Coast in Queensland, Australia, may have had a conflict of interest — an undisclosed business venture selling pillows to help posture. Another report, published by pbs.org/newshour, raised another problem: the authors hypothesized about the link between the skull bone growths and technology, but didn't measure the subjects' phone usage.

The study, which was originally published in 2018 in the respected peer-reviewed journal, Scientific Reports, caused a sensation last week after being brought to light first in a recent BBC article and then The Washington Post. (Scientific Reports is a part of Nature Research, which also publishes the renowned science journal Nature.) NBC News reported it Thursday, noting that the Australian study highlighted how little is known about the effects of excessive technology use on the human body.

When reached Tuesday by NBC News via email, Shahar said he was aware of the concerns about conflict of interest. He responded that his research “never suggested any specific treatment” to participants as a result of their bone growths and that “we simply suggested that based on our conclusion, posture maintenance from an early age is prudent.”

According to Scientific Reports, authors are required to declare “any competing financial and/or non-financial interests in relation to the work described.”

Typically, any potential benefit for study authors that may conflict with the study’s results are disclosed by the researchers involved. Shahar told NBC News that he has offered a disclosure statement to the journal “to be included in the document should they choose to add it.”

Studies are typically peer-reviewed, meaning they are looked over by several other experts in the field before an article is published, as a way to ensure its quality and accuracy. This way, they are more likely to be scientifically valid and reach reasonable conclusions. Nature, which uses this practice, reviewed the study and signed off on its publication.

There has been little scientific research on the physical effects of long periods of cellphone use, especially among young people. In response to criticism, Shahar acknowledged that the researchers speculated about the cause of the bony growths. In the study, they wrote, “Although the 'tablet revolution' is fully and effectively entrenched in our daily activities, we must be reminded that these devices are only a decade old and it may be that related symptomatic disorders are only now emerging.”

But Shahar said that he and co-author Mark Sayers didn't claim they had actually studied their subjects' technology use.

“We simply pointed out the surprising prevalence and magnitude of these bony growths in the young adult population,” he said in the email to NBC News on Tuesday. “Not speculating in the discussion what may be a cause would have left this discussion incomplete, as most similar studies do so.”

According to the University of the Sunshine Coast in Australia, Sayers has more than 60 peer-reviewed publications in scientific journals and has presented at more than 30 national and international conferences. The 2018 study was Shahar’s first paper with senior authorship.

NBC News reached out to Scientific Reports for comment about the published study. A spokesperson for the journal earlier told PBS NewsHour that it was looking into the paper and would “take action where appropriate.”

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