In the new survey, most people were open to those simpler types of tests: Three-quarters said they'd have a blood pressure check, while 68 percent were willing to undergo blood sugar or cholesterol tests.
But fewer were willing to have their lifestyle choices scrutinized for a financial reward.
Just over half said they'd take part in a health plan-monitored exercise regimen to lose weight or control diabetes. And only about 38 percent would follow a specific diet to help lower their blood pressure or cholesterol.
"This survey shows that there is a substantial opportunity for health plans to test and monitor the health status and health risk behaviors of health plan members, but that they would have to be extremely careful to avoid a potentially explosive backlash," said Harris Poll Chairman Humphrey Taylor.
Blumenthal-Barby agreed on the need for a cautious deployment of financial incentives. "We need to make sure that incentives do not become coercive," she said.
Taylor pointed out that "all such monitoring and testing would have to be, and be seen to be, strictly voluntary. Any suggestion that pressure was being put on people to participate would be disastrous."
According to Blumenthal-Barby, one of the striking findings from the poll was that while 49 percent of people were "very willing" to undergo genetic tests, only 28 percent would attend a health class or keep an online diet-and-exercise diary.
"People would rather have genetic tests than keep a diary," she said.
That could be because a blood test sounds much easier, or because people often believe they are unlikely to have any "bad" genes, Blumenthal-Barby noted. But again, she said, the results suggest that many people do not grasp the full implications of giving away genetic information.
The poll, which surveyed 2,033 Americans online between Oct. 21-23, asked about hypothetical situations -- what people "would" do if a health plan were to offer incentives for various tests.
Blumenthal-Barby said she wasn't aware of any employers or insurers currently offering incentives in exchange for genetic tests -- which, in addition to being intrusive, are costly.