U.S. Health Survey Team Targets County Residents : Medical: Interviewers are seeking random subjects for osteoporosis study. Free exams and cash are offered.

Answering a knock at the door in the next few weeks may get Ventura County residents a free physical, an opportunity to contribute to medical science and a little extra cash.

Interviewers from the U. S. Department of Health and Human Services are fanning out across the county in search of random subjects for a national health survey on osteoporosis.

Ventura County is one of 88 counties randomly selected across the nation for the six-year study by the National Center for Health Statistics.

The survey is expected to provide a broad base of information because it encompasses such a wide group of residents from across the country, said field operations director Robert Cuellar.

“Disease doesn’t differentiate,” Cuellar said. “We are all susceptible and we can all benefit from this.”

Respondents also will be queried on general health issues and undergo physical exams that last three to four hours and include allergy tests, a gallbladder ultrasound and a dental exam.

Using U. S. census data, interviewers displaying government identification will visit 2,000 households to get the required number of 486 people to participate, Cuellar said. Workers will screen households to find people within certain age groups, including babies who are at least 2 months old.

There is no obligation to participate, but to sweeten the offer, adults who take part get $50, and children receive $30. Respondents will be selected by April 6.

Three teams of Health and Human Services workers have been roaming the nation since the fall of 1988 gathering data for the study. Cuellar’s team comes most recently from Houston. They travel in four trailers and set up camp, usually in a central location within the selected county. In Ventura County, they chose Oxnard, in a lot next to St. John’s Regional Medical Center.

The trailers are equipped with machines that test lung capacity, heartbeats and hearing and a camera that photographs the back of the eye to check for diabetic hemorrhaging.

But the poking and prodding will be at a minimum, Cuellar said.

“Most of our equipment is computerized, so we don’t even touch the respondents for most of the tests,” he said.

Much of the information gleaned from the survey is used to produce national health statistics and standards, the kind of figures that pop up in growth charts in pediatricians’ offices.

“You’ve heard people talk about, ‘They say the national average is this,’ ” Cuellar said. “Well, we are they.”

The results of the tests will remain confidential, he said. If any dangerous health concerns crop up during the physical, the respondent will be told immediately. Otherwise, results should take about two months to arrive at the respondent’s home by mail.

The primary goal is to research the incidence and cause of osteoporosis, but the data will also be used by a number of federal agencies--from the Centers for Disease Control to the Environmental Protection Agency.

Although the sampling of counties is random and meant to arrive at a national standard, Cuellar said he and his medical personnel will sometimes come across health information unique to an area.

“Like valley fever,” he said. “We didn’t have that in Houston.”

The number of people willing to participate is usually quite high, but Cuellar said some people tell the interviewers they have health insurance and don’t need a physical, then slam the door. Unfortunately, he said, if they fit within the criteria of the study, they have to be included, even though no health information on them is available.

“That’s just lost data,” he said. “This survey impacts everyone. It’s not just for people without insurance.”