The 10 minutes it took for Tony Martinez to learn if he was HIV-positive were a little tense, the 41-year-old Gilbert resident confessed.

Martinez, who works in downtown Phoenix, had just filled two vials of blood Thursday at a small health-screening laboratory called Lab Express at Fifth Avenue and McDowell Road.

Less than 30 minutes after he walked into the clinic, a lab employee whispered the test results to Martinez.

"Yes," Martinez softly blurted, pumping his fist in the air as if he had just bought a winning lottery ticket.

He had tested negative for virus that causes AIDS.

"It's always nice to know," he said later. "I really was expecting it to be fine. I never have engaged in any crazy activity that would have put me at risk. But you never know. That's the thing."

Martinez is among a number of patients who are choosing a less traditional way of getting tested for everything from sexually transmitted diseases to high cholesterol - one that is cheaper, more convenient, more private and faster.

The companies providing the testing are small clinics that don't require a preliminary visit to a physician like their much larger and more traditional competitors in the Valley - LabCorp and Sonora Quest Laboratories.

Like Martinez, the companies say clients like the anonymity, low prices and quick convenience they offer.

But the growing industry is not without its critics who say the interaction between a person and their physician is critical to their well-being.

CONVENIENCE IS KING

In a city choking with drive-through restaurants, pharmacies and even coffee shops, it's no wonder the number of walk-in clinics offering speedy health screenings is growing.

Any Lab Test Now is the most recent business offering fast, discreet and low-cost lab results to anyone brave enough to endure a poke to the arm.

The firm opened its first clinic next to Fry's Marketplace in a strip mall at 90th Street and Via Linda in Scottsdale.

"Time is money for a lot of these folks," said Kurt Bernd, managing partner for the franchise. "They like the fact that they can just get in and get out."

Sean Carson, a Scottsdale resident, stopped into the clinic Wednesday evening after receiving a circular advertising the company.

Carson, who has diabetes, said he's considering getting his tests at the lab because his medical bills are beginning to pile up.

"There's going to be quite a significant savings," he said.

TOO ENTREPRENEURIAL

Despite the benefits, some people criticize companies offering walk-in, no-referral lab testing.

Chic Older, executive vice president of the Arizona Medical Association, said the practice concerns him because it severs the doctor-patient relationship.

"It's almost like a form of practicing self-medicine," he said.

He argues that patients may not know what tests they should order, and many of them don't have the expertise to interpret the results. That could pose serious dangers.

"What concerns me is that it's more entrepreneurial than (it's) intended to be helpful," he said.

Lab Express has physicians on staff. Any Lab Test Now employs medical assistants and trained phlebotomists to draw blood.

However, Bernd defends his services, saying his staff makes it clear to patients that they can't dispense medical advice.

"If somebody has a question or anything like that, then obviously we're going to encourage them to seek a physician," he said.

He also said clinic staff will advise patients to seek medical care if their test results show their health may be at risk.

"We're certainly not trying to interfere with any kind of a doctor-patient relationship," he said. "(We're) just basically empowering people. A lot of people may not go to their physician. Men are very typical of resisting doctor visits. We think this is a great tool for those individuals that may not go see their doctor."

UNINSURED CLIENTS BEHIND POPULARITY

One factor driving the demand for walk-in testing is the number of people living without health insurance, proponents say.

According to the most recent statistics from the U.S. Census Bureau, 21 percent of Arizona's residents were uninsured in 2006. That's about 1.3 million people out of the state's 6.27 million residents.

"People who don't have insurance are a good part of our market," said Scott Farrell, Lab Express president.

Farrell, who started the company 19 years ago, said uninsured clients represent a $2 million market.

That may sound like a lot, but Farrell said it could be even more lucrative if he could figure out a way to more effectively reach that audience.

In 2005, he spent $70,000 in advertising on a popular radio station in the Valley.

"We got terrible, terrible response," he said. "It's like we threw money away."

But Farrell admits he's doing very well when factoring in his walk-in business as well as the $4 million a year his firm earns providing employee drug testing to Valley corporations.

There are four Lab Express clinics in the Valley and two in Tucson, but Farrell is planning to open two labs in Las Vegas and four in Arizona.

ANONYMITY IS PART OF APPEAL

A sign on the door at Any Lab Test Now says "Discreet & confidential."

Anonymity is a key reason why walk-in labs appeal to consumers, convincing them to bypass their doctor's office, said Farrell, who also closely guards client records.

He explained that a big reason for that is because insurance companies have access to patient records and can raise premiums based on lab results.

For example, he said a patient who gets frequent STD tests can be deemed to be a high risk by his insurer.

"Anything you do is going to be in your record," he said. "Insurance companies - they have access to all of that."

Walk-in health screeners aren't required to divulge client records to insurance companies, he added.

Bernd argues that the anonymity empowers people with options they wouldn't have otherwise. He posed a hypothetical scenario involving a customer with high cholesterol who wishes to purchase a life insurance policy.

"(It) might be a motivator for that person to get it down before they might go in and apply for a huge life insurance policy," he said.