(Adds HCA report, analysts, share movement)
Oct 16 (Reuters) - UnitedHealth Group Inc said on Thursday that its third-quarter net profit increased as patients' use of medical services remained "restrained," helping to keep the cost of health insurance claims down.
Americans have been using healthcare services lightly in recent years due to the economic downturn and as their out-of-pocket costs for doctor and hospital visits have increased.
Investors have been watching to see if that trend has turned this year as the national healthcare reform law, Obamacare, expanded insurance to millions more people and the economy has improved.
UnitedHealth, the largest U.S. managed care company, reported earnings of $1.6 billion, or $1.63 per share, up from $1.57 billion, or $1.53 per share, a year earlier.
Analysts on average had expected a profit of $1.53 per share, according to Thomson Reuters I/B/E/S.
UnitedHealth said the percentage of medical claims that it spent on care fell by 90 basis points to 79.7 percent in the third quarter. At its commercial business, which includes health plans in which UnitedHealth manages the risk, its medical care ratio decreased 220 basis points to 79.1 percent.
Leerink Partners analyst Ana Gupte said in a research note that the lower-than-expected ratios should offset fears of a rising medical cost trend after hospital operator HCA Holdings Inc reported strong admissions volumes on Wednesday.
Hospital stocks benefit as more people use their facilities, while insurer shares suffer as those companies typically must pay out more to cover these services.
HCA shares were up about 5 percent at $68.25 in premarket activity, while UnitedHealth dipped 0.5 percent to $81.75.
UnitedHealth said revenue increased to $32.8 billion from $30.6 billion a year earlier. Sales in its Optum division, which includes its healthcare technology and pharmacy benefits businesses, rose 21 percent to $12 billion.
For 2014, the company expects net earnings of $5.60 to $5.65 per share, up from its previous forecast of $5.50 to $5.60. Analysts had been expecting $5.58.
BMO Capital Markets analyst Jennifer Lynch said in a research report that the increased outlook for 2014 indicated the company had stable fundamentals.
(Reporting by Caroline Humer; Editing by Pravin Char and Lisa Von Ahn)