The justices ruled 4-3 Wednesday that the $1 million per-person limit on a doctor's malpractice insurance applies to the combined losses of a stroke victim, his wife and son, instead of treating the patient and his family as separate claims under the policy. The ruling in a Butler County case is a "nuance" adding to a similar ruling in August regarding wrongful death malpractice cases, an attorney for the insurance company said.

State medical and attorney trade groups had filed arguments in the most recent case, but the high court sidestepped their debate over whether a 1994 law limiting claims in automotive policies would apply in this case.

Dr. James Thomson was treating John Watkins over several months when he had a massive stroke in 1999. Watkins sued for malpractice, and his wife, Sherri, and son, Sean, claimed negligence and loss of companionship.

Thomson's malpractice insurance policy limits coverage to $1 million for each person treated by the doctor, with a $3 million cap on claims for the coverage period, typically one year. About 80 percent of malpractice policies in the state contain those coverage limits, according to the Ohio State Medical Association.

OHIC Insurance Co. successfully argued that the wife and son weren't treated by the doctor and therefore couldn't seek separate awards. The policy says so-called "derivative claims" fall under the patient's $1 million cap.

The Watkins family argued that an earlier Supreme Court ruling, arising from an auto insurance policy, said such policy limits may not be enforced. Butler County Common Pleas Court agreed, which would have entitled the family to the policy's $3 million per-year limit.