Older patients who think they have been admitted to a hospital are finding that's not always the case and a consumer's group has pursued legal action to protect their Medicare rights. The Center for Medicare Advocacy filed a lawsuit last week against the federal government to halt hospitals' use of "observation status" in a way that deprives seniors of their hospital coverage under Medicare Part A. The advocacy center, based in Connecticut, brought the lawsuit on behalf of seven Medicare beneficiaries but said hospitals' improper use of observation status has escalated in recent years. Improper use of observation status is "illegal, harmful and unfair," said Judith Stein, executive director of the advocacy center. The group wants the Centers for Medicare & Medicaid to stop misuse of observation status, which hospitals do for financial reasons and to keep readmission numbers low.