Ohio Revised Code Title XIII. Commercial Transactions § 1335.05

No action shall be brought whereby to charge the defendant, upon a special promise, to answer for the debt, default, or miscarriage of another person; nor to charge an executor or administrator upon a special promise to answer damages out of his own estate; nor to charge a person upon an agreement made upon consideration of marriage, or upon a contract or sale of lands, tenements, or hereditaments, or interest in or concerning them, or upon an agreement that is not to be performed within one year from the making thereof; unless the agreement upon which such action is brought, or some memorandum or note thereof, is in writing and signed by the party to be charged therewith or some other person thereunto by him or her lawfully authorized.

No action shall be brought to charge a person licensed by Chapter 4731. of the Revised Code to practice medicine or surgery, osteopathic medicine or surgery, or podiatric medicine and surgery in this state, upon any promise or agreement relating to a medical prognosis unless the promise or agreement is in writing and signed by the party to be charged therewith.