Online aggregation sites like Travelocity or Hotels.com have changed the travel market by empowering consumers to shop around for the best deals. Now this web phenomenon is expanding into healthcare.

Websites that compile and compare medical provider costs and services are gaining popularity, giving Americans a way to compare the costs of various medical services, according to Bloomberg. Castlight Health provides prices and rates the quality of service from various doctors, hospitals and labs, for employees whose companies register with the website. Another example is OutOfPocket.com, a free site that compiles user-submitted data about medical costs.

These cost and quality comparison sites are especially useful in the current economy, when more Americans are living on tighter budgets and the financial burden of rising medical expenses are taking their toll on American households. The average American family with an employee-based health plan can expect to pay more than $20,000 in healthcare costs this year, meaning the bill might eat up about 40 percent of a family's household income.

The price of a given medical procedure can vary widely depending on the individual's circumstances including the patient's type of insurance, the medical provider's rates, and geography. For example, a recent study found that in California, a patient could pay anywhere from $1,529 to $182,955 to have an appendix removed, with the median price for the procedure coming in at $33,611. The sites can help consumers to better understand their specific costs by providing pricing information that may otherwise be hard for individuals to access.

Cost comparisons are also useful to the increasing number of Americans that lack healthcare insurance, including the 26 percent of the population ages 16 to 24 who are uninsured at least part of the year. More people are also looking for more affordable options as high-deductible health insurance plans are becoming more common among workers. This kind of insurance requires patients to pay a large sum of their health expenses, sometimes up to thousands of dollars, out of their own pocket before any coverage sets in. Though they have a buffer in the event of a catastrophic medical emergency, workers under these plans are responsible for most of their expenses and thus are likely to want to shop around and compare prices.