- Email: [email protected]
“Where's the Science?”
CCWhereys the Eddie Hedrick, BS, MT(ASCP), Columbia, Missouri
Science?” CIC
Historically, infection control professionals, organizations, and regulatory agencies have developed and implemented a multitude of devices, policies and procedures, and concepts to protect patients and staff from exposure to infection. Although the intent is to reduce the risk of infection, often these efforts have not been evaluated for their efficacy. Many tactics have become so entrenched in health care that, even when shown to be unnecessary or ineffective, they continue to be used. Thirty years ago, Dr R.E.O. Williams gave the opening speech at the First International Conference on Nosocomial Infection. In the main portion of his speech he stated, I believe one of the principal reasons we have so often failed to persuade our colleagues in hospitals to do the antiseptic things that we think they ought to is that we have so rarely provided them with convincing evidence
that,
if they
do, their
patients
quickly and survive in significantly
will
get better
more
greater numbers.’
At that time he challenged the infection munity with his closing remarks.
control
com-
Bacteriologists and physicians treating infectious disease have called a variety of tunes as they climbed on the succession of bandwagons in the last 30 years, and many of their tunes must have contributed to the changes in the incidence of hospital infection that we think we have seen. It is lucky that we have been able to call the tune without having to pay the piper, for the one outstanding omission from almost all of the preventative measures is any attempt to estimate costeffectiveness. We could devise any number of elaborate preventative measures, but, even if money were unlimited, the ability of hospital personnel to observe a plethora of precautions is limited, no matter how vigorous the admonitions of the Hospital Infection Control Committee. It should be our aim at this conference to put the bandwagons in perspective, to determine those procedures whose value is really established, and to delineate those that still require validation.’
From University Columbia.
Hospitals
and
Clinics,
University
of Missouri-
Am J Infect
Copyright Infection
2000;28:66-7.
0 2000 by the Association Control and Epidemiology, Inc.
0196-6553/2000/$12.00
66
Control
+ 0
17/52/l
for 01030
Professionals
in
the Second International Eichoff declared,
Our major failure, unquestionably, has been our failure to answer the challenge given to us a decade ago by Dr Williams. We have not, to date, provided clear evidence of the efficacy of most of the things we recommend to prevent or control nosocomial infections.*
In 1990, at the Third International Conference, Dr Richard Dixon reviewed the progress in infection control during the previous 20 years. He pointed out that since the original conference in 1970, we have proven the efficacy of only 7 infection control practices.) In today’s health care environment, where the future of health care lies in the ability to provide quality care at a lower cost, it is crucial that all new actions recommended by the infection control community are subjected to scientific and economic evaluation before implementation. Old recommendations must also be routinely evaluated for their continued efficacy. This new column (entitled “Where’s the Science?“) will examine a widely advocated or promoted practice or device for which there is no obvious scientific support and will ask the question, “Where’s the science?” Within its pages, we will attempt to determine the efficacy of the practice and either locate the science or identify gaps in our knowledge. The column may also encourage the elimination of rituals that are not effective. This first issue examines the science regarding surgical face masks and particulate respirators. SURGICAL FACE RESPIRATORS
Reprint requests: Eddie Hedrick, B.S. MT(ASCP), CIC, University Hospitals and Clinics, One Hospital Drive, Columbia, MO 6.5212 AJIC
Ten years later at Conference, Dr Theodore
MASKS
VS PARTICULATE
The outbreaks of tuberculosis that occurred in the late 1980s stimulated the reevaluation of tuberculosis control practices4 In 1990, the CDC reorganized its guidelines regarding tuberculosis and consolidated them into one document. At that time the words “particulate respirator” replaced “surgical mask” in the guidelines. Up until that time, surgical masks were used routinely to protect health care workers from exposure to pulmonary tuberculosis. This change created a great deal of confusion and concern in the health care community, because there was little information to prove that wearing surgical masks was associated with an increased incidence of tuberculosis infection in those who used them. After the health care community spent a great deal of money and went through an assortment
AJIC
Volume 28, Number
Hedrick
1
of particulate respirators, including dust-mist, dustmist-fume, powered air-purifying respirators (PAPRs), high-efficiency particulate air filters (HEPAs), and finally the N-95, the Centers for Disease Control and Prevention (CDC) published a paper that attempted to explain the conflicting recommendations. The reason given for the change was that “standard surgical masks may not be effective in preventing inhalation of droplet nuc1ei.“5 In the same paragraph, the authors acknowledged that “the efficacy of particulate respirators in protecting susceptible persons from inhalation of tuberculosis has not been demonstrated.” Interestingly, many of the outbreaks of tuberculosis that stimulated the rewriting of the tuberculosis guidelines were brought under control without the use of particulate respirators.6-8 There is no doubt that particulate respirators provide better filtration than the surgical mask, and most would argue correctly, “What is the harm in obtaining the higher level of protection the particulate respirator offers?” The problem is the lack of science to guide the practice. Surgical masks have been used for years to protect health care workers who care for patients with tuberculosis. There was never any indication that these masks did not provide sufficient protection9 However, because they were originally designed for surgical purposes, they are not classified or certified as respirators. The National Institute for Occupational Safety and Health (NIOSH) is the arm of the CDC that has regulatory responsibility for respirator certification. NIOSH requires that all particulate respirators be used in conjunction with an effective respiratory protection program. A respiratory protection program requires a medical evaluation, “fit-testing,” “fit checking,” and so forth for those who wear the devices. The cost of these extra requirements is very high,‘@‘* but the benefits have not been determined.13 The Occupational Safety and Health Administration’s (OSHA) Proposed Rule Regarding Occupational Exposure to Tuberculosis requires the use of N-95 respirators and the expensive respiratory protection program, leaving health care facilities little recourse other than to comply. The CDC has said that the development of its guideline was an evolutionary process that would not stop with publication. As the results of additional research become available, the guidelines will change to incorporate the most current scientific findings. Unfortunately once codified into OSHA law, these requirements are very difficult to change even in the face of good science. With new cases of tuberculosis in American-born citizens remaining at an all-time low for the past several years, it is unlikely that the science of respiratory protection for tuberculosis will evolve any further. There is little incentive. The idea1 studies to resolve the issue will probably never be done because of regulatory and ethical issues.13
67
Wearing an N-95 respirator in place of a surgical mask may not actually raise health care costs, because these devices can be worn several times before being discarded, although this too is controversial.‘4 However, fit testing is extremely costly and may not determine whether the device leaks after a period of use.‘5J6 The increased cost and the documented benefit of this requirement to the health care worker should be ascertained because ultimately, the patient pays. I believe we are justified in asking, “Where’s the science?” References 1. Williams REO. Changing perspectives in hospital infection, In: Proceedings of the International Conference on Nosocomial Infections. American Hospital Association. Baltimore: Waverly Press; 1971. p. l-11. 2. Eichoff TC. Nosocomial infections-a 1980 view: progress, priorities and prognosis. Am J Med 1981;70:381-8. 3. Dixon RE. Historical perspective. The Landmark Conference in 1980. Am .I Med 199 I;9 1 (Suppl 3B):6S7S. 4. Centers for Disease Control and Prevention. Guidelines for preventing the transmission of Mycobacterium fuberculosis in health care facilities, 1994. MMWR 1994;43(No. RR-13):1-132. 5. Jatvis WR, Bolyard EA. Bozzi Cl. et al. Respirators, recommendations, and regulations: the controversy surrounding protection of health cane workers from tuberculosis. Ann Intern Med 1995; 122: 142-6. 6. Wenger PN. Otten J. Breeden A, Orfas D, Beck-Sague CM, Jawis Wm. Control of nosocomial transmission of multidrug-resistant Mycobacterium ruberculosis among healthcare workers and HIVinfected patients. Lancet 1995;345:235-40. Maloney S, Pearson M, Gordon M, Del Castillo R. Boyle J, Jatvis WR. Nosocomial multidrug-resistant tuberculosis revisited: assessing the efficacy of recommended control measures in preventing transmission to patients and health care workers. Ann Intern Med 1995;122:90-5. Dooley SW, Jarvis WR, Snider DE. Mycobacterium tuberculosis. In: Hospital epidemiology and infection control. Baltimore: Williams & Wilkins: 1996. p. 1220. 9. Woeltze KF, L’Ecuyer PB, Seiler S. Fraser VJ. Varied approaches to tuberculosis control in a multihospital system. Infect Control Hosp Epidemiol 1997;18:548-53. 10. Adal KA. Anglim AM, Palumbo CL, et al. The use of high-efficiency particulate respirators to protect hospital workers from tuberculosis. N Engl J Med 1994;331:169-73. 11. Nettleman MD, Frederickson M. Good NL, et al. Tuberculosis control strategies: the cost of particulate respirators. Ann Intern Med 1994; 12 1:37-40. 12. Kellerman S, Tokars JI. Jarvis WR. The costs of complying with CDC tuberculosis guidelines at hospitals with a history of multidrug-resistant Mycobocmirrm r~cberculosis outbreaks [abstract]. Infect Control Hosp Epidemiol 1996; 17: 17. 13. Fennelly KP. Personal respiratory protection against mycobacteriurn tuberculosis. Clin Chest Med 1997;18:1-17. 14. Rivera P, Louther J, Mohr J. Cambell A, DeHovitz, Sepkowitz KA. Does a cheaper mask save money? The cost of implementing a respiratory personal protective equipment program. Infect Control Hosp Epidemiol 1997;18:24-7. 15. Brown V, Bishop C. Rutala WA, Weber DJ. HEPA respirators and tuberculosis in hospital workers [letter; comment]. N Engl J Med 1994;331:1659. 16. Segal Maurer S, KaIkut GE. Environmental control of tuberculosis: continuing controversy. Clin Infect Dis 1994;19:299-308.
Science?” CIC
Historically, infection control professionals, organizations, and regulatory agencies have developed and implemented a multitude of devices, policies and procedures, and concepts to protect patients and staff from exposure to infection. Although the intent is to reduce the risk of infection, often these efforts have not been evaluated for their efficacy. Many tactics have become so entrenched in health care that, even when shown to be unnecessary or ineffective, they continue to be used. Thirty years ago, Dr R.E.O. Williams gave the opening speech at the First International Conference on Nosocomial Infection. In the main portion of his speech he stated, I believe one of the principal reasons we have so often failed to persuade our colleagues in hospitals to do the antiseptic things that we think they ought to is that we have so rarely provided them with convincing evidence
that,
if they
do, their
patients
quickly and survive in significantly
will
get better
more
greater numbers.’
At that time he challenged the infection munity with his closing remarks.
control
com-
Bacteriologists and physicians treating infectious disease have called a variety of tunes as they climbed on the succession of bandwagons in the last 30 years, and many of their tunes must have contributed to the changes in the incidence of hospital infection that we think we have seen. It is lucky that we have been able to call the tune without having to pay the piper, for the one outstanding omission from almost all of the preventative measures is any attempt to estimate costeffectiveness. We could devise any number of elaborate preventative measures, but, even if money were unlimited, the ability of hospital personnel to observe a plethora of precautions is limited, no matter how vigorous the admonitions of the Hospital Infection Control Committee. It should be our aim at this conference to put the bandwagons in perspective, to determine those procedures whose value is really established, and to delineate those that still require validation.’
From University Columbia.
Hospitals
and
Clinics,
University
of Missouri-
Am J Infect
Copyright Infection
2000;28:66-7.
0 2000 by the Association Control and Epidemiology, Inc.
0196-6553/2000/$12.00
66
Control
+ 0
17/52/l
for 01030
Professionals
in
the Second International Eichoff declared,
Our major failure, unquestionably, has been our failure to answer the challenge given to us a decade ago by Dr Williams. We have not, to date, provided clear evidence of the efficacy of most of the things we recommend to prevent or control nosocomial infections.*
In 1990, at the Third International Conference, Dr Richard Dixon reviewed the progress in infection control during the previous 20 years. He pointed out that since the original conference in 1970, we have proven the efficacy of only 7 infection control practices.) In today’s health care environment, where the future of health care lies in the ability to provide quality care at a lower cost, it is crucial that all new actions recommended by the infection control community are subjected to scientific and economic evaluation before implementation. Old recommendations must also be routinely evaluated for their continued efficacy. This new column (entitled “Where’s the Science?“) will examine a widely advocated or promoted practice or device for which there is no obvious scientific support and will ask the question, “Where’s the science?” Within its pages, we will attempt to determine the efficacy of the practice and either locate the science or identify gaps in our knowledge. The column may also encourage the elimination of rituals that are not effective. This first issue examines the science regarding surgical face masks and particulate respirators. SURGICAL FACE RESPIRATORS
Reprint requests: Eddie Hedrick, B.S. MT(ASCP), CIC, University Hospitals and Clinics, One Hospital Drive, Columbia, MO 6.5212 AJIC
Ten years later at Conference, Dr Theodore
MASKS
VS PARTICULATE
The outbreaks of tuberculosis that occurred in the late 1980s stimulated the reevaluation of tuberculosis control practices4 In 1990, the CDC reorganized its guidelines regarding tuberculosis and consolidated them into one document. At that time the words “particulate respirator” replaced “surgical mask” in the guidelines. Up until that time, surgical masks were used routinely to protect health care workers from exposure to pulmonary tuberculosis. This change created a great deal of confusion and concern in the health care community, because there was little information to prove that wearing surgical masks was associated with an increased incidence of tuberculosis infection in those who used them. After the health care community spent a great deal of money and went through an assortment
AJIC
Volume 28, Number
Hedrick
1
of particulate respirators, including dust-mist, dustmist-fume, powered air-purifying respirators (PAPRs), high-efficiency particulate air filters (HEPAs), and finally the N-95, the Centers for Disease Control and Prevention (CDC) published a paper that attempted to explain the conflicting recommendations. The reason given for the change was that “standard surgical masks may not be effective in preventing inhalation of droplet nuc1ei.“5 In the same paragraph, the authors acknowledged that “the efficacy of particulate respirators in protecting susceptible persons from inhalation of tuberculosis has not been demonstrated.” Interestingly, many of the outbreaks of tuberculosis that stimulated the rewriting of the tuberculosis guidelines were brought under control without the use of particulate respirators.6-8 There is no doubt that particulate respirators provide better filtration than the surgical mask, and most would argue correctly, “What is the harm in obtaining the higher level of protection the particulate respirator offers?” The problem is the lack of science to guide the practice. Surgical masks have been used for years to protect health care workers who care for patients with tuberculosis. There was never any indication that these masks did not provide sufficient protection9 However, because they were originally designed for surgical purposes, they are not classified or certified as respirators. The National Institute for Occupational Safety and Health (NIOSH) is the arm of the CDC that has regulatory responsibility for respirator certification. NIOSH requires that all particulate respirators be used in conjunction with an effective respiratory protection program. A respiratory protection program requires a medical evaluation, “fit-testing,” “fit checking,” and so forth for those who wear the devices. The cost of these extra requirements is very high,‘@‘* but the benefits have not been determined.13 The Occupational Safety and Health Administration’s (OSHA) Proposed Rule Regarding Occupational Exposure to Tuberculosis requires the use of N-95 respirators and the expensive respiratory protection program, leaving health care facilities little recourse other than to comply. The CDC has said that the development of its guideline was an evolutionary process that would not stop with publication. As the results of additional research become available, the guidelines will change to incorporate the most current scientific findings. Unfortunately once codified into OSHA law, these requirements are very difficult to change even in the face of good science. With new cases of tuberculosis in American-born citizens remaining at an all-time low for the past several years, it is unlikely that the science of respiratory protection for tuberculosis will evolve any further. There is little incentive. The idea1 studies to resolve the issue will probably never be done because of regulatory and ethical issues.13
67
Wearing an N-95 respirator in place of a surgical mask may not actually raise health care costs, because these devices can be worn several times before being discarded, although this too is controversial.‘4 However, fit testing is extremely costly and may not determine whether the device leaks after a period of use.‘5J6 The increased cost and the documented benefit of this requirement to the health care worker should be ascertained because ultimately, the patient pays. I believe we are justified in asking, “Where’s the science?” References 1. Williams REO. Changing perspectives in hospital infection, In: Proceedings of the International Conference on Nosocomial Infections. American Hospital Association. Baltimore: Waverly Press; 1971. p. l-11. 2. Eichoff TC. Nosocomial infections-a 1980 view: progress, priorities and prognosis. Am J Med 1981;70:381-8. 3. Dixon RE. Historical perspective. The Landmark Conference in 1980. Am .I Med 199 I;9 1 (Suppl 3B):6S7S. 4. Centers for Disease Control and Prevention. Guidelines for preventing the transmission of Mycobacterium fuberculosis in health care facilities, 1994. MMWR 1994;43(No. RR-13):1-132. 5. Jatvis WR, Bolyard EA. Bozzi Cl. et al. Respirators, recommendations, and regulations: the controversy surrounding protection of health cane workers from tuberculosis. Ann Intern Med 1995; 122: 142-6. 6. Wenger PN. Otten J. Breeden A, Orfas D, Beck-Sague CM, Jawis Wm. Control of nosocomial transmission of multidrug-resistant Mycobacterium ruberculosis among healthcare workers and HIVinfected patients. Lancet 1995;345:235-40. Maloney S, Pearson M, Gordon M, Del Castillo R. Boyle J, Jatvis WR. Nosocomial multidrug-resistant tuberculosis revisited: assessing the efficacy of recommended control measures in preventing transmission to patients and health care workers. Ann Intern Med 1995;122:90-5. Dooley SW, Jarvis WR, Snider DE. Mycobacterium tuberculosis. In: Hospital epidemiology and infection control. Baltimore: Williams & Wilkins: 1996. p. 1220. 9. Woeltze KF, L’Ecuyer PB, Seiler S. Fraser VJ. Varied approaches to tuberculosis control in a multihospital system. Infect Control Hosp Epidemiol 1997;18:548-53. 10. Adal KA. Anglim AM, Palumbo CL, et al. The use of high-efficiency particulate respirators to protect hospital workers from tuberculosis. N Engl J Med 1994;331:169-73. 11. Nettleman MD, Frederickson M. Good NL, et al. Tuberculosis control strategies: the cost of particulate respirators. Ann Intern Med 1994; 12 1:37-40. 12. Kellerman S, Tokars JI. Jarvis WR. The costs of complying with CDC tuberculosis guidelines at hospitals with a history of multidrug-resistant Mycobocmirrm r~cberculosis outbreaks [abstract]. Infect Control Hosp Epidemiol 1996; 17: 17. 13. Fennelly KP. Personal respiratory protection against mycobacteriurn tuberculosis. Clin Chest Med 1997;18:1-17. 14. Rivera P, Louther J, Mohr J. Cambell A, DeHovitz, Sepkowitz KA. Does a cheaper mask save money? The cost of implementing a respiratory personal protective equipment program. Infect Control Hosp Epidemiol 1997;18:24-7. 15. Brown V, Bishop C. Rutala WA, Weber DJ. HEPA respirators and tuberculosis in hospital workers [letter; comment]. N Engl J Med 1994;331:1659. 16. Segal Maurer S, KaIkut GE. Environmental control of tuberculosis: continuing controversy. Clin Infect Dis 1994;19:299-308.