The phrase "a serious factor in" is correct and usable in written English.
It can be used when discussing the importance or influence of a particular element in a situation or decision-making process.
Example: "The rising cost of living is a serious factor in the decision to relocate for many families."
Alternatives: "a significant element in" or "an important consideration in".
After his death, however, Sicily was not a serious factor in mainland Greek politics.
Some of those making it a serious factor in their decision-making may be shady operators.
But despite some near misses, he never won a primary and was never a serious factor in the Republican race.
Cutting costs is essential, Ms. Middleton said, though giving clients the information they need is also a serious factor in their business.
A better option: recognize that mental health is a serious factor in gun suicide, and policies that target suicide might be more effective than government databases.
Sterling's quest is to be a serious factor in ensuring Manchester City regain the league title and the club becomes a genuine continental heavyweight.
Electromechanical oscillations in power system are becoming a serious factor to limit power transfer in inter-connected power systems in China.
The detection of H3+ in diffuse interstellar clouds came as a surprise, however, and suggested a serious (factor of ~100) problem in the simple model of diffuse cloud chemistry.
From a clinical point of view, muscle injury represents a serious factor limiting the therapeutic outcome in the fields of trauma surgery, transplantation, plastic surgery and orthopedics.
(S) A new, but potentially serious factor in Dutch domestic politics is its large, poorly integrated Muslim population, currently numbering just under 1 million, or 5.8percentt of the population.
Depression is becoming more and more serious factor in a subpopulation of the elderly.
