National survey sparks dispute about latex risk

NHANES can’t gauge HCW problem, official says

Can the survey used to track the nation’s most serious health problems also reveal the risk of latex allergy to health care workers?

Leading researchers say the data collected in the National Health and Nutrition Examination Sur vey (NHANES) by the National Center for Health Statistics aren’t complete enough to compare the risk between health care workers and the general public. But in an independent analysis, Allegiance Healthcare Corp. of McGaw Park, IL, a leading manufacturer of latex and synthetic medical gloves, asserts that health care workers are not at greater risk of latex allergy.

Out of 20,050 adult respondents to the survey, 5,524 were tested for latex sensitivity using the AlaStat immunoassay produced by Diagnostic Products Corp. of Los Angeles. According to the Allegiance analysis, 1,026 respondents tested positive, including 21% of health care workers and 19% of non-health care workers. (The Centers for Disease Control and Prevention has not yet released its own analysis of the data.)

"The results of NHANES III are consistent with several studies published over the past few years which show that there is little difference in latex sensitization rates among health care workers and the general population," concluded Neil Roth, MD, an epidemiologist and consultant to Allegiance.

Michele Pearson, MD, a medical epidemiologist with the hospital infections program at the Centers for Disease Control and Prevention in Atlanta, notes that there are potential problems with any analysis of the NHANES data that attempts to gauge risk and exposure. For example, the occupation codes used to identify health care workers could include workers who don’t wear latex gloves. While the survey asked about glove use, it didn’t specify type of glove and doesn’t include any detailed information about exposure.

Furthermore, the "health care worker" category would exclude workers who develop allergic symptoms and change jobs, she notes.

When NHANES is repeated in about three years, it may reveal a clearer picture of latex allergy, says Pearson. Yet it can’t carry the scientific weight of a controlled study, she adds.

"We were trying to find out how many people might have evidence of sensitization and were there any patterns. Did [sensitization rate] differ from one group to another?" says Pearson. "We hoped this might be a baseline to look at trends over time.

"Neither the NHANES study or virtually any study out today can tell you what the risk is [of latex allergy]," says Pearson, who is analyzing the NHANES data.

"These studies can tell you the prevalence, not the incidence," explains Pearson, noting that only by following exposed workers over time can researchers determine the risk. "I think that question is still to be answered."

(Editor’s note: The Allegiance Healthcare Corp. analysis of NHANES data is available on the company’s Web site at www.allegiance.net.)