Ohio Rev. Code Ann. § 5731.08

The value of the gross estate shall include the value of all property, to the extent of any interest therein of which the decedent has made a transfer except in the case of a bona fide sale for an adequate and full consideration in money or money's worth, by trust or otherwise, where the enjoyment thereof was subject on the date of the decedent's death to any change through the exercise of a power, in whatever capacity exercisable, by the decedent alone or by the decedent in conjunction with any other person to alter, amend, revoke or terminate.