A Healthy Rise in PacifiCare’s Bottom Line : Earnings: Third-quarter profits up 78%. Purchase of an HMO last year improved an already solid period.

PacifiCare Health Systems Inc. said Wednesday that its earnings rose 78% for the latest quarter, partly because of its December purchase of another health-maintenance organization.

Profit for the company’s third fiscal quarter, which ended June 30, was $14.6 million, or 60 cents a share, up from $8.2 million, or 32 cents a share, for the same period last year. Revenue totaled $447 million, up 40% from $319 million. About a third of that increase resulted from its acquisition of the Health Plan of America HMO.

PacifiCare said it would have had a good quarter even without the added profit and revenue from Health Plan of America. More customers signed up for its Secure Horizons Medicare HMO for the elderly, the company said, after it increased spending to advertise the program.

Medicare profits aren’t quite as high as those from PacifiCare’s regular HMO business, where they run about 4.5 cents on the dollar. But elderly Medicare patients mean more business because they require more treatment than younger patients.

Another bright spot: Fewer HMO members were hospitalized during the quarter, which meant that the plan saved money.

President Terry Hartshorn said that the company is getting more adept at finding less-expensive alternatives, such as outpatient surgery or home-health care, for its patients. Each day in the hospital costs an average of $1,000, Hartshorn said, while the alternatives typically cost much less.

PacifiCare, based in Cypress, runs HMOs in the West, operates Columbia General insurance companies in 34 states and has other health-related subsidiaries.