Summary Box: Humana's 4Q net income falls 57 pct

THE RESULTS: Humana Inc.'s fourth-quarter net income fell 57 percent to $107.3 million, or 63 cents per share, weighed down by $1.02 per share of expenses. Revenue rose 9.4 percent to $8.35 billion.

ENROLLMENT GAINS: Humana's Medicare Advantage membership increased to approximately 1.89 million in January, up about 130,000 from the end of 2010, reflecting the company's better-than-expected performance during the recently ended enrollment period.

BIG BOOST: Membership in Humana's stand-alone Medicare prescription drug plans reached about 2.39 million in January, up more than 630,000 members from the end of 2010, helped by a partnership with retail giant Wal-Mart Stores Inc.