WATERLOO - After his sister suffered a heart attack roughly a year ago, Mark Frost took a closer look at his own health.

Like many Americans seeking medical information, the Waterloo man's first stop was the Internet. Using Allen Hospital's free HeartAware assessment, Frost learned that his age and family history increased his risk of experiencing coronary trouble.

The 60-year-old scheduled a consultation at Allen, also free for HeartAware users, and reviewed the results with a registered nurse who also took his cholesterol and blood pressure readings.

"It was a nice little reminder that I needed to get back on track," said Frost, who discussed diet and exercise options during his appointment. "It's a great system - it's easy to get to online, and it really gives you a nice place to start."

Frost's case highlights the advantages of online disease screening tests. When used correctly the questionnaires prompt patients to take a proactive approach to their health care, addressing risks before they become realities.

"A lot of people aren't aware how susceptible they are to various things, like hypertension or high cholesterol," said Dr. Arla McVicker, a family physician at Covenant Clinic's Evansdale office. "And if we can catch it early, there's lots of things we can do to manage it and decrease morbidity."

More generalized tests, such as the one found at realage.com, can prompt patients to change their habits. After answering questions regarding their health, family history and lifestyle, users are assigned a "real age." Smoking, skipping sunscreen or slacking at the gym can all age patients prematurely.

"People tend to forget that they are responsible for their health and their doctor can only offer guidance," said McVicker, who refers patients to the Web page. "This site promotes that way of thinking."

Still, not all tests are supported by science, said Dr. Stephen Riggs, of Covenant Clinic's Kimball Avenue office. The best questionnaires are based on research and sponsored by reputable medical organizations. Others are scams - pseudo-science quizzes designed to hawk diet pills or health supplements.

"No online screening test is ever going to be able to provide the kind of insight and specialized testing and advice your doctor is trained to give," he said.

Web questionnaires are best used when physicians and patients talk about the results together, added Riggs.

"There are some very good screening tools available - tests that encourage people to focus on preventative health care," he said. "But you need to be smart. Not all tests are created equal."