Squeezed by $4-a-gallon milk and gas, people are waiting longer to go to the doctor and ignoring their medical bills -- decisions that are hurting health care companies.

On Thursday, LabCorp shared its pain with investors. During its second-quarter earnings report, the Burlington company cut its profit and revenue projections for the full year. Investors reacted immediately. Shares dropped $4.78 to close at $66.87 Thursday, down 6.7 percent.

CEO David King said that to prepare for debt it won't be able to collect, the company would set aside an additional $45 million in the second quarter.

King said that an informal LabCorp survey showed that the number of physician visits is down and the number of people without insurance is up.

LabCorp contracts with health insurers to run medical lab tests for their members. It employs more than 25,000 people, including about 1,000 in the Triangle.

Health care has long been buffered from the ups and down of the economy. But for the first time in more than a decade, prescription drug sales are declining. Demand for cosmetic surgery is down.

"People are struggling with mortgage and credit card debt, they are more price-sensitive, and they're deciding not to go to the doctor," said Dr. Kevin Schulman, a health care policy expert at Duke University.

In the past six years, health care spending has nearly doubled, while wages have barely budged, Schulman said. At the same time, Americans who have insurance watched their out-of-pocket expenses skyrocket because of higher co-payments and deductibles.

"We've never been in this position before," he said.

Bad debt collections tend to run higher in the South, where LabCorp has a strong presence, said Arthur Henderson, a Jefferies analyst who tracks the $50 billion lab-test industry.

Henderson said the company has a lot going for it in spite of the fact that it missed some analyst expectations in the second quarter.

He said that investors are likely to warm up to LabCorp again when the next quarterly earnings report comes in. Until then, he said, "this is probably going to be dead money."

LabCorp reported $140 million in profits on $1.15 billion in sales during the three months ended June 30. The profits excluded $35.9 million in one-time charges related to job cuts in Canada.

Revenue for the quarter was up 10 percent, but below the $1.16 billion analysts had expected, according to Thomson Reuters. Excluding the one-time charges, profits rose about 5.5 percent to meet analysts' expectations.

The worsening financial situation among consumers mostly affected LabCorp's routine-testing business, which is about 65 percent of its business. Routine tests include drug screening of job applicants and annual checkups, such as Pap smears.

More elaborate tests, like those that examine genetic material or predict the likelihood of certain cancers, remain in demand. These tests are more expensive and more profitable. They now make up about 35 percent of LabCorp's business, but are expected to constitute about 40 percent of revenue in three to five years.