The phrase "a long established pattern of" is correct and usable in written English.
It can be used to describe a consistent and enduring behavior or trend that has been observed over time.
Example: "The company has a long established pattern of prioritizing customer satisfaction above all else."
Alternatives: "a well-established trend of" or "a longstanding practice of".
Mr. Jackson has a long-established pattern of firing advisers, lawyers, business managers, agents and other personnel as they fall out of favor.
The suit argues that the N.C.A.A. "has engaged in a long-established pattern of negligence and inaction with respect to concussions and concussion-related maladies sustained by its student-athletes, all while profiting immensely from those same student-athletes".
Their arrival "follows a long-established pattern of economic migration, which for years has placed great demands on our country's capacity," she said, noting that in the first half of 2010, one-sixth of all live births in her country's public hospitals were to Haitian mothers.
DCF described her as "uniquely dangerous, in that no other youth at the Connecticut Juvenile Training School has exhibited such a long-established pattern of assaults".
Weight loss was a common reason that men provided for making changes to a long-established pattern of heavy drinking.
Following a long established pattern, Plantard "recruited" the "initiate" Pelat soon after his death and included him as the most recent Priory of Sion Grand Master.
That would be breaking a long-established pattern.
Political and rights groups said that if the United States did not try to curb the general, it would be following a long-established pattern.
Breaking a long-established pattern in labor negotiations, Mayor Michael R. Bloomberg plans to demand that city teachers agree to a significantly smaller raise in their next contract or face the prospect of 2,500 job cuts.
With no formal experience in education administration, Mr. Bennet was following a long-established pattern, according to people who have worked with him over the years: the willingness to leap into unfamiliar waters.
