Health insurer Aetna Inc. ranked No. 1 in a national survey of health plans and their dealings with physicians, Reuters reports. Aetna was quickest at resolving claims, taking on average 27 days to pay a doctor, compared with 35 for UnitedHealth Group Inc. and 36 for WellPoint Inc. The lowest ranked commercial health insurers were WellPoint and UnitedHealth, based on overall performance, according to the report issued by Athenahealth Inc., which sells electronic business services to doctors and medical groups. The rankings relied on administrative, medical policy and financial data from 2007 from 12,000 medical providers. Article