TB mask savings doubtful for some hospitals

Those with HEPA may not save by switching

The widely projected cost-savings for hospitals due to the new "N-95" tuberculosis respirators may not materialize at many institutions for a common sense reason: Workers may simply use more of the less expensive masks than they did of their more expensive predecessors, an epidemiologist recently reported.

In particular, hospitals that treat a high prevalence of TB patients and already are using the high efficiency particulate air (HEPA) respirators may realize little cost-savings by switching to cheaper masks, said Ken Sepkowitz, MD, hospital epidemiologist at St. Clare's Hospital and Health Center in New York City.

"I don't think we are going to save a plugged nickel from the N95 series," he said recently of the annual conference of the Society for Healthcare Epidemiology of America (SHEA) in Washington, DC.

HEPA too expensive, uncomfortable

Last year, after a protracted regulatory quagmire, the new N95 class was approved by the National Institute of Occupational Safety and Health (NIOSH) in Washington, DC. The move was welcomed by health care officials because the HEPA mask -- widely criticized as too expensive and uncomfortable -- had been deemed the only acceptable TB mask on the market by federal regulators in 1994. With the regulatory changes allowing other masks to be used for TB, the general perception was that hospitals would save money by phasing out HEPA respirators -- priced in the range of $5 -- in favor of an increasing array of cheaper masks. (See Hospital Infection Control, November 1995 pp. 137-141.)

St. Clares began using HEPA respirators in 1994 after using a variety of less expensive masks in 1992 and 1993, Sepkowitz explained, noting that despite the regulatory changes the hospital has stayed with its HEPA program. To assess whether cost savings would have been realized by using less expensive masks, Sepkowitz compared current expenditures to the costs of using cheaper masks in 1992 and 1993. Annual mask costs were determined via purchasing records and estimated administrative costs. Total TB patient days in respiratory isolation were calculated using daily infection control log books. Mask cost per TB isolation day rose steadily from 1992 to 1994, but fell sharply in 1995 despite continued use of the HEPA masks, he said. A key reason was that health care workers were getting used to reusing the HEPA over a total recommended period of eight hours, which could take a month to accumulate for some staff, he noted. Newly approved, cheaper, but less durable masks are unlikely to withstand multiple wearings and may be discarded after few uses, he said.

'Comfort remains a problem'

"The cost per isolation day -- which was our index in this study -- decreased significantly in the second year of HEPA program," Sepkowitz said. "I think human nature is the key. The HEPA looks like it costs a lot and people don't throw it away. The other stuff looks cheap and people throw it away."

Asked about reports of workers pulling the HEPA masks aside or wearing them too loose, Sepkowitz said infection control compliance monitoring suggests the masks are being worn properly at the hospital. Though comfort is an issue with the masks, he noted the main point of the analysis was to show that the predicted windfall savings will not be the case for some hospitals switching to the N95 masks.

"The comfort and wearibility of HEPA remains a problem," he said. "I don't endorse HEPA on the basis of this. [But] a cheaper mask does not necessarily save money." *