The phrase "are confirmed by multiple" is correct and usable in written English.
It can be used when discussing evidence or findings that have been validated by several sources or studies.
Example: "The results of the experiment are confirmed by multiple peer-reviewed studies."
Alternatives: "are validated by several" or "are corroborated by multiple".
Swift, it seemed, was too modest to comment herself, though the donation was confirmed by multiple outlets.
The C.I.A. was stung to find out its analysts had mistakenly thought that Iraq weapons information had been confirmed by multiple sources, when it came from only a single source; that analysts had relied on a fabricating Iraqi defector and spin material from Iraqi exiles; and that this blather made its way into documents and speeches used by the Bush administration to justify war.
Both associations were confirmed by multiple logistic regressions.
The pedostratigraphy division was confirmed by multiple environmental magnetism parameters (Wu et al. 2010).
Their aptitude to achieve the required performance was confirmed by multiple numerical simulations under different initial conditions and various scenarios.
The results from our studies differ from those using NIH3T3 cells, but have been confirmed by multiple other groups.
In fact, it has been confirmed by multiple spectrum measurement campaigns that this scarcity is only virtual and is caused by the underutilization of the bandwidth [1, 2].
The mechanism of this reaction is affected substantially by the presence of adatoms produced by preceding reactions, as was confirmed by multiple reaction cycles and supported by computational studies.
The proliferation of informal information channels today with the Internet and social media can benefit the warning dissemination process, because individuals are more likely to respond to a warning if it is confirmed by multiple sources (Cola [1996]; Mileti and Sorenson [1990]).
