The phrase "a study examined" is correct and usable in written English.
It can be used when referring to research or analysis conducted by a study on a particular topic or issue.
Example: "A study examined the effects of sleep deprivation on cognitive performance."
Alternatives: "a study investigated" or "a study analyzed".
If a study examined both ED and hospital care, only the ED metrics were included.
A study examined three autoinjectors using both methods (n = 30 for the user trials).
To support policy-making, a study examined possible future strategies for these meadows in the west of the Netherlands.
A study examined three different factors: warmer-than-usual surface atmosphere conditions (related to global warming); sea-ice thinning prior to the melting season (also related to global warming); and an August storm that passed over the Arctic, stirring up the ocean, fracturing the sea ice and sending it southward to warmer climes.
A study examined the role of socioeconomic status in how heterosexism impacted queer people of color.
A study examined the relationship between facing financial hardship and engaging in higher-risk sexual practices among queer men.
David Schrank, a researcher at the Texas Traffic Institute, recently co-authored a study examining traffic congestion nationwide.
Two Notre Dame political scientists, Madhav Joshi and J. Michael Quinn, last year published a study examining 196 cease-fires and peace deals from 1975 to 2011.
The civic pride argument has been invoked often enough that in 2004, economists Peter Groothuis, Bruce Johnson and John Whitehead published a study examining whether or not it actually exists.
Promising results were reported in a study examining a new vaccine for advanced melanoma, a deadly form of skin cancer.
HEALTH economists at Yale University have produced a study examining the health effects of losing one's job a timely topic.
