The phrase "and is then often" is correct and usable in written English.
It can be used to describe a sequence of events or actions that typically occur after a certain point.
Example: "The process begins with an analysis of the data, and is then often followed by a review of the findings."
Alternatives: "and is frequently" or "and is typically".
Unfortunately, they perform regularly worse when validated in new patients and are then often redeveloped.
And 300,000 to 500,000 guns are stolen each year -- the weapons presumably were not properly locked up -- and are then often used to commit crimes, said Jack Calhoun, the crime prevention council's president and chief executive.
Such a series is obtained by successive additions of alkali to a solution of the acid (or of a strong acid to a solution of the base) and the procedure is then often termed a pH titration.
When both houses of the legislature and the governor's office are not controlled by the same party, an agreement often cannot be reached, and the redistricting map is then often drawn by a court.
The further ongoing monitoring and liaison with the specialist is then often managed by the local health professional.
The urge passes within one to two minutes if not relieved, and the material in the rectum is then often returned to the colon where more water is absorbed.
The IUD is then often replaced by less effective methods.
And trustees are then often pressured to take ever bigger risks with the money they do have, in the hope that they can close the deficit and so discharge the company's obligation.
More chemicals such as other antioxidants, thermal stabilizers, plasticizers, impact modifiers, clarifiers, colorants, mold release agents and rheology modifiers are then often added to the resin that is then heated and molded in various stages to make a product, or a single piece of a multi-piece product, each often composed of different chemicals.
