Health
Protection
Network
Evidence Table
All studies which are critically appraised as part of the literature review are assigned a grade of evidence based on the SIGN 50 methodology
grading system (SIGN, 2004), which allows scientific studies to be assessed for quality using a number of reviewing forms (available from the
SIGN website -
http://www.sign.ac.uk). The main conclusions from the studies are summarized along with a brief description of the study
quality in an Evidence Table. Studies, which have sufficient quality and specifically answer a defined research question are grouped together to
enable formation of a “considered judgment” based on this information. This “considered judgment” is then used as the basis for formulation of
recommendations.
This system allows formulation of recommendations supported by good quality observational studies in the case when RCTs are not available
for practical or ethical reasons, as is generally found in infection control literature.
Levels of evidence
The following grades were given to the papers included in this evidence table:
1++ High quality meta analyses, systematic reviews of RCTs, or RCTs with a very low risk of bias
1+ Well conducted meta analyses, systematic reviews of RCTs, or RCTs with a low risk of bias
1- Meta analyses, systematic reviews of RCTs, or RCTs with a high risk of bias
2++ High quality systematic reviews of case-control or cohort studies
High quality case-control or cohort studies with a very low risk of confounding, bias, or chance and a high probability that the relationship is causal
2+ Well conducted case control or cohort studies with a low risk of confounding, bias, or chance and a moderate probability that the relationship is causal
2- Case control or cohort studies with a high risk of confounding, bias, or chance and a significant risk that the relationship is not causal
3 Non-analytic studies, e.g. case reports, case series
4 Expert opinion
- 1 -
Question: When should patients wear a FRSM? (SICPs)
Study
Study type
Evidence level
Intervention
Comparison
Outcome measures
Ref 1387. Baig, S,
Patients wearing a
Rashid, T and Saleem,
mask when being
M. Protection from
treated for epistaxis
Patients not wearing a
blood aerosol
via cautery, anterior
mask when being
Number of blood
contamination when
nasal packing or
treated for epistaxis
splatters on physicians
managing epistaxis: a
RCT with high risk of
anterior/posterior
via cautery, anterior
eye shield
3
study of the
bias
packing.
nasal packing or
effectiveness of a
anterior/posterior
patient mouth mask.
(Classic Surgical
packing.
2015. Ear, Nose and
Mask – Kimberley
Throat Journal. Vol 94
Clark ≥96% (BFE),
(9) p394-398.
≥97% (PFE)
Assessment of evidence:
4 blood splatters (13.3%) in mouth mask group
8 blood splatters (26.7%) in control group
No p-values or confidence intervals to indicate levels of statistical significance. Participants were randomly allocated but authors do not indicate
how this was done. Lack of information regarding the characteristics of participants.
This study suggests that the wearing of surgical masks by epistaxis patients during treatment may reduce the number of blood splashes to HCW
facial PPE. However, due to limited information and small sample sizes, conclusions cannot be definitively drawn.
It is also unclear whether the need for patients to wear a surgical mask in this scenario is necessary if facial PPE provides adequate protection. This
study supports the recommendation that mask/eye protection be worn by HCWs when bodily fluid splashes are anticipated.
This study had a high risk of bias as the blood splatters were counted by the physician who had just removed their own mask. Furthermore, this
- 2 -
method relied on the visual capabilities of the physician alone and this lacks scientific rigour.
Ref 5541. Raad, I,
Hanna, H, Osting, C,
Nosocomial infection
Hachem, R, Umphrey,
with invasive
J, Tarrand, J,
pulmonary
Kantarjian, H and
aspergillosus with
Bodey, G. P. Masking
symptoms appearing
of neutropenic
Use of ‘high
Non-mask use by
at least 14 days after
patients on transport
efficiency’ masks by
patients when
admission.
from hospital rooms is
patients when
transported out of
associated with a
Observational study
4
transported out of
their rooms during
Results of air
decrease in
their rooms during
hospital construction
sampling.
nosocomial
hospital construction
works.
aspergillosis during
works.
Rates of IPA infection
construction. 2002.
of those with
Infection Control and
haematological
Hospital
malignancy within the
Epidemiology. Vol 23
community.
(1) p41-43
Assessment of evidence:
Graded as level 4 evidence as a ‘concise communication’ and therefore not peer-reviewed.
The incidence of nosocomial IPA decreased from 0.73 per 1000 hospital patient days to 0.24 per 1000 hospitalised patient days (p=<0.001).
Incidence decreased significantly for both leukaemia patients (p=<0.001) and bone marrow transplant patients (p=0.02). This was despite a
significant increase in community acquired IPA in those with haematological malignancy (p=0.002) and a significant increase in aspergillus
positive indoor air samples from period 1 to period 2 (p=0.003). Authors were not aware of any other confounding intervention that could have
impacted on IPA incidence.
Unclear as to what specific type of surgical mask was used but authors state that masks filter to a particle size of 0.1µm and are
“able to filter 99%
- 3 -
of Aspergillus organisms”. Total patient numbers studied is not provided, results are given as per 1000 hospital patient days. The intervention was
not applied during the same environmental conditions as masks were not worn during a period of lesser construction and worn during a period of
heavy construction. However, intuitively, this should have resulted in an increase in IPA cases not a decrease.
This study weakly supports the recommendation that immunocompromised patients who are being transported out with their room during a period
of hospital construction should be given a surgical mask to wear if it can be tolerated.
Question: When should patients wear a FRSM? (TBPs)
Study
Study Type
Evidence Level
Intervention
Comparison
Outcome measure
Nicola J Rowbotham, Sally
Includes an
Systematic review
C Palser, Sherie J Smith &
assessment of
assessing the evidence
3 included studies. Two
Alan R Smyth. Infection
evidence
base behind different
studies found face masks to
prevention and control in
concerning the
Systematic
infection control
be effective in reducing
cystic fibrosis: a systematic
efficacy of face
Review
2+
precautions used to
aerosol PA load and an RCT
review of interventions.
masks in
prevent infection in
found no difference in exam
2019. Expert Review of
reducing
cystic fibrosis
room contamination rate.
Respiratory Medicine, 13:5,
infection for
patients.
425-434
CF patients.
Assessment of evidence:
The systematic review was well conducted, however, due to the low amount/quality of studies identified, meta-analysis was not conducted. There
was no assessment of publication bias. Meta-analysis of the three studies identified was not done/appropriate and although one was an RCT all
three measured indirect indicators of infection transmission prevention eg. PA aerosol loads/room contamination. All three studies have been
included in the critical appraisal phase of this surgical mask review; Wood et al 2018, Stockwell et al 2018 and Zuckerman et al 2015.
This systematic review was completed to a reasonable standard but lacked some key featured that allow for clear interpretation of the results
found. The authors did not asses risk of bias in the included publications and there was a lack of detail on the methods applied to combine
individual study findings. For these reasons the evidence level applied to this systematic review reflects these lacking elements.
- 4 -
Surgical mask
Wood, M. E, Stockwell, R.
(TECNOL
Uncovered
1. Percentage of participants
E, Johnson, G. R, Ramsay,
Fluidshield
coughing and
with detectable P. aeruginosa
K. A, Sherrard, L. J, Jabbour,
Fog-Free Surgical
talking
following each intervention
N, Ballard, E, O'Rourke, P.,
Mask; Kimberly-
measured 2m from source
Kidd, T. J, Wainwright, C. E,
Clark Professional)
Knibbs, L. D, Sly, P. D,
(ASTM Level 3).
2. Log¹º number of P.
Morawska, L and Bell, S. C.
aeruginosa CFUs collected
Face masks and cough
N95 respirator (N95
2m from source.
Controlled trial
etiquette reduce the cough
3
Particulate
study
aerosol concentration of
Filter Respirator;
3. Percentage reduction in
pseudomonas aeruginosa in
Kimberly-Clark).
aerosol P. aeruginosa
people with cystic fibrosis.
concentration (log-
2018. American Journal of
Masks worn by CF
transformed CFUs)
Respiratory and Critical Care
patients chronically
Medicine. Vol 197 (3) p348-
infected with P.
355
aeruginosa for 5
minute periods of
coughing or talking.
Assessment of evidence:
This study showed a statistically significant reduction in numbers of P. aeruginosa CFU detected in aerosols, 2 meters from the source when
surgical masks were worn during coughing compared to uncovered coughing. This study also showed that the number of P. aeruginosa CFUs
produced during uncovered talking is comparable to that produced when talking whilst wearing a surgical mask.
Limitations of this study include the inability to directly link the number of CFUs detected to risk of transmission of infection. The masks used are
slightly different to those employed in the UK as they are ASTM level 3 masks. These have greater fluid resistance than an type IIR mask but the
same BFE of >98%. Masks were only worn for 9 minutes and the reductive effects provided after this time are unknown.
This study adds to the evidence base for coughing CF patients to wear surgical masks when in communal areas with other CF patients although is
perhaps not of a high enough quality/size to support a change to recommendations.
“Johnson et al., who
investigated how surgical
Expert opinion
4
Ref 3069. Bunyan D, Ritchie
masks and N95 respirators,
L, Jenkins D and Coia JE.
worn by patients with
confirmed influenza, would
Respiratory and facial
- 5 -
protection: a critical review
prevent the generation of
of recent literature. 2013.
infectious airborne particles.
Journal of Hospital Infection.
Surgical masks and N95
Vol 85 p165-169.
respirators appeared to be
equally and highly effective
in filtering out influenza-
contaminated particles when
worn by infected patients.42
This small study did not
investigate whether masks or
respirators worn by patients
reduced the numbers of
cross-infection events in a
real clinical setting, which
would be the decisive test for
this approach.”
Assessment of evidence:
This expert opinion is based on a review. The document provides guidance on surgical masks and respirators. It advises on the standards that both
these types of masks should meet in the UK, when they should be worn, how they should be fit checked/tested if necessary and how they should be
removed and disposed of.
It refers to relevant health and safety/governmental legislation.
Caution is advised as this guidance was published in 2014 and some aspects may be out of date.
NOT TO BE USED FOR FORMAL RECOMMENDATIONS
“relative risk for any virus
Ref ID 6107
Participants donned a
detection with mask versus
Milton, D. K., Fabian, M. P.,
Controlled
ear-loop surgical
Participants did
without a mask was 0.85 and
Cowling, B. J., Grantham, M.
experimental
3
mask (Kimberly-
not don a
L., McDevitt, J. J. 2013.
study
Clark, Roswell,
surgical mask
borderline statistically
Influenza virus aerosols in
significant (CI 0.72 to 1.01;
GA).
human exhaled breath:
McNemar’s test p =0.06).”
- 6 -
particle size, culturability,
(p: 2)
and effect of surgical masks.
PLoS Pathogens. Volume
9(3). p: e1003205
“The geometric mean copy
number in the fine particle
fraction without a facemask
was 110 (95% CI 45 to 260)
and the facemasks produced
a 2.8 fold reduction in copy
number (95% CI 1.5 to 5.2,
p= 0.001)”(p: 2)
“Combining the coarse and
fine fractions, we detected
viral RNA in 29 (78%)
subjects when wearing
facemasks and 35 (95%)
when not wearing facemasks
(McNemar’s test p= 0.01).
Surgical masks produced a
3.4 (95% CI 1.8 to 6.3) fold
reduction in viral copies in
exhaled breath.” (p:2)
“This finding supports
current Centers for Disease
Control and Prevention
recommendations that
healthcare facilities
encourage patients with
influenza-like illness to don
surgical facemasks as one
component of an influenza
infection control program” (p:3)
- 7 -
Assessment of evidence:
Low quality, small study that lacks validity, reliability and generalisability in relation to answering the research question it is most relevant to.
However, as the authors state , the findings do support the CDC recommendation for healthcare facilities to encourage use of facemasks by patients
with ILI as part of a wider IPC effort.
Limitations:
The sampler used in the study was specifically for fine and ultrafine particles which would therefore mean it would not detect large droplets
(>50 µm).
Sample was of volunteers from the community, most of whom were either students or staff at the university of Massachusetts. Not
healthcare professionals.
No further details of participant demographics assessed
Lacks validity and generalisability
Measured results of forced coughs
the mask description does not include enough detail to confirm the exact mask model and associated properties of the mask (FRSM?)
“When transporting a patient
with symptoms of influenza,
the patient should be
encouraged to wear a
Ref XX. Department of
surgical mask to minimise
Health and Health Protection
droplet dispersal. The mask
Agency. Pandemic influenza:
should be worn throughout
Summary infection control
Guidance
4
the period of transport.”
guidance for ambulance
services during an influenza
“If the patient cannot tolerate
pandemic. 2009.
a mask, good respiratory
hygiene should be
encouraged and a tissue or
similar can be offered to hold
against their mouth and
nose to ‘catch’ secretions
- 8 -
from coughing, sneezing or
blowing the nose.”
HICPAC and Centres for
Disease Control. Core
Infection Prevention and
Expert
Control Practices for Safe
opinion/consens
4
Healthcare Delivery in All
us
Settings – Recommendations
of the Healthcare Infection
Control Practices Advisory
Committee. 2017.
Assessment of evidence:
“Prompt patients and visitors with symptoms of respiratory infection to contain their respiratory secretions and perform hand hygiene after contact
with respiratory secretions by providing tissues, masks, hand hygiene supplies and instructional signage or handouts at points of entry and
throughout the facility”
“Surgical/procedure
masks are used for
several different
purposes,
Ref XX. Occupational
including the
Safety and Health Act
following: […]
(OSHA). Guidance on Guidance / Expert
Placed on sick people
Preparing Workplaces
4
opinion
to limit the spread of
for an
infectious respiratory
Influenza Pandemic.
secretions to others.”
2009.
(pp 21)
- 9 -
This document specifies from the outset that the information provided is purely advisory guidance and is not a standard or a regulation. This differs
from the legal obligations of employers and employees that are found within other OSHA documents such as the OSHA standards or the
Occupational Safety and Health Act (OSH Act).
Caution is given regarding the appropriate use of both surgical masks and respirators:
“Surgical masks are not designed or certified to prevent the inhalation of small airborne contaminants. These small airborne contaminants are too
little to see with the naked eye but may still be capable of causing infection. Surgical/procedure masks are not designed to seal tightly against the
user’s face. During inhalation, much of the potentially contaminated air passes through gaps between the face and the surgical mask, thus avoiding
being pulled through the material of the mask and losing any filtration that it may provide. Their ability to filter small particles varies significantly
based upon the type of material used to make the surgical mask, and so they cannot be relied upon to protect employees against airborne infectious
agents.” (pp 22)
“Note: Additional respirator and surgical mask guidance for healthcare workers has been developed and is available at
www.pandemicflu.gov/plan/healthcare/maskguidancehc.html. This document, “Interim Guidance on Planning for the Use of Surgical Masks and
Respirators in Health Care Settings during an Influenza Pandemic,” provides details on the differences between a surgical mask and a respirator,
the state of science regarding influenza transmission, and the rationale for determining the appropriate protective device.” (pp 26)
Medical masks should be
part of a number of IPC
supplies that are accessible
Ref XX. World Health
within the healthcare
Organisation (WHO). 2014.
environment.
Infection prevention and
control of epidemic-and
“In people with ARIs,
pandemic-prone acute
encourage the use of
respiratory infections in
respiratory hygiene (i.e.
health care. [Online].
Agree:
Guidance
NA
NA
covering the mouth and nose
Available at:
recommend
during coughing or sneezing
https://apps.who.int/iris/bitstr
with a medical mask
eam/handle/10665/112656/9
[surgical or procedure
789241507134_eng.pdf;jsess
mask], cloth mask, tissue,
ionid=90E49145E816EB709
sleeve or flexed elbow),
14AF47FFF7EC42E?sequen
followed by hand hygiene, to
ce=1
reduce the dispersal of
respiratory secretions
containing potentially
- 10 -
infectious particles (Strong
recommendation, very low
quality of evidence)…” (pp
31)
It is recommended that
patients with Acute
Respiratory Infection or TB
should always don a medical
mask when outside of
isolation areas.
“Encourage the use of
medical masks by patients
with ARI during transport or
when care is necessary
outside of the isolation room
or area” (pp 18)
Assessment of evidence:
Within this document a medical mask is defined as:
“Medical mask
Also known as a surgical or procedure mask. As personal protective equipment, a facial mask is intended to protect caregivers and health-care
workers against droplet-transmitted pathogens, or to serve as part of facial protection for patient-care activities that are likely to generate splashes
or sprays of blood, body fluids, secretions or excretions (Annex A provides details of usage and standards for medical masks). In this document, the
term refers to disposable masks only.” (pp xviii).
“A.2.3 Medical mask standards
Medical masks protect the wearer's nose and mouth from inadvertent exposures (e.g. through splashes) to blood and other body fluids. However,
there are no minimum standards or standardized testing methods for mask filter efficiency, and available masks vary widely in the efficiency of
their filters. As an example of standards, the Association of Perioperative Registered Nurses recommends that surgical masks filter particles of at
least 0.3 μm for regular use and 0.1 μm for laser use (i.e. to protect the wearer against laser smoke), or have 90–95% bacterial filtration efficiency.
Furthermore, surgical masks are classified as medical devices in Europe and the US and are regulated appropriately. For example, the US Food
and Drug Administration (FDA) standards for surgical masks are as follows: 1
- 11 -
• Fluid resistance:
– American Society for Testing and Materials (ASTM) F 1862–00a: standard test method for resistance of surgical mask to penetration by synthetic
blood.
• Filtration efficiency:
– particulate filtration efficiency (PFE) – 0.1 μ polystyrene latex sphere;
– bacterial filtration efficiency (BFE) – ASTM F 2101–01: standard test method for evaluating the BFE of surgical masks using a biological
aerosol of Staphylococcus aureus.
• Air exchange (differential pressure, delta-P):
– measure of breathability and comfort of surgical masks.
• Flammability:
– Class 1 and Class 2 flammability rating material for use in the operating room (OR);
– Class 4 flammability rating is not appropriate for use in the OR (would be labelled as “not for OR use”).
• Biocompatibility.” (pp 41)
“Respiratory hygiene/cough
etiquette (source
containment of infectious
Siegel, J. D., Rhinehart, E.,
respiratory secretions in
Jackson, M. and Chiarello, L.
symptomatic patients,
et al. Health Care Infection
beginning at initial point
Control Practices Advisory
of encounter, eg, triage and
Committee (HICPAC).
reception areas in
2007. 2007 guideline for
emergency departments
isolation precautions:
AGREE:
and physician offices)” … in
Guidance
NA
NA
preventing transmission of
Recommend
this instance healthcare
infectious
workers should …
agents in health care settings.
“Instruct symptomatic
American Journal of
persons to cover mouth/nose
Infection Control. 35:S65-
when sneezing/
164.
coughing; use tissues and
dispose in no-touch
receptacle; observe
hand hygiene after soiling of
hands with respiratory
- 12 -
secretions; wear
surgical mask if tolerated or
maintain spatial separation,
.3 feet if
possible.” (pp S74)
Recommendation: surgical
mask when:
“placed on
coughing patients to limit
potential dissemination of
infectious respiratory
secretions from the patient to
others (ie, respiratory
hygiene/cough etiquette).” (S99)
Transportation of patients:
“When transport is
necessary, applying
appropriate
barriers on the patient (eg,
mask, gown, wrapping
in sheets or use of
impervious dressings to
cover the affected
areas) when infectious skin
lesions or drainage
are present, consistent with
the route and risk of
transmission.” (pp S103)
Assessment of evidence:
This set of recommendations is supported by a review of scientific literature. It is split into multiple parts many of which contain relevant
information to answer this RQ.
- 13 -
Ref XX. Internal Clinical
Guidelines Team.
Tuberculosis – Prevention,
diagnosis, management and
AGREE:
.
service organisation. NICE
Guidance
Recommend
NG33. Methods, evidence
and recommendations
(2016).
Assessment of evidence:
“1.5.1.12 Explain to inpatients with suspected infectious or confirmed pulmonary or
laryngeal TB that they will need to wear a surgical mask in the hospital
whenever they leave their room. Ask them to continue wearing it until they have
had at least 2 weeks of treatment. [2016]” (pp 45)
Ref 1879. Coia JE, Ritchie L
and Fry C. Use of respiratory
and facial protection. 2014.
Nursing Times. Vol 110 (4)
p18-20.
AND
Expert
4
Ref 2987. J.E. Coia, L.
consensus
Ritchie, A. Adisesh, C.
Makison Booth, C. Bradley,
D. Bunyan, G. Carson, C.
Fry, P. Hoffman, D. Jenkins,
N. Phin, B. Taylor, J. S.
Nguyen-Van-Tam, M.
Zuckerman, The Healthcare
Infection Society Working
- 14 -
Group on Respiratory and
Facial Protection. Guidance
on the use of respiratory and
facial protection. Journal of
hospital infection 85(2013)
165-169
AND
Ref 3069. Bunyan D, Ritchie
L, Jenkins D and Coia JE.
Respiratory and facial
protection: a critical review
of recent literature. 2013.
Journal of Hospital Infection.
Vol 85 p165-169.
Ref 1879 is a summary of ref 2987 and ref 3069 was the review that informed ref 2987.
To protect others from the wearer as a source of infection.
This expert consensus provides guidance on surgical masks and respirators. It advises on the standards that both these types of masks should meet
in the UK, when they should be worn, how they should be fit checked/tested if necessary and how they should be removed and disposed of.
It refers to relevant health and safety/governmental legislation.
Caution is advised as this guidance was published in 2014 and some aspects may be out of date.
Epic3: National
Evidence-Based
Guidelines for
Preventing
Guidance/expert
AGREE: recommend
Healthcare-Associated
opinion
(but level 4 here)
Infections in
NHS Hospitals in
England. H.P.
Loveday, J.A. Wilson,
- 15 -
R.J. Pratt, M.
Golsorkhi, A. Tingle,
A. Bak, J. Browne, J.
Prieto, M. Wilcox.
2014. Journal of
Hospital Infection. S1-
S70
Authors state that healthcare workers may use “standard fluid repellent masks to prevent respiratory droplets from the mouth or nose being expelled
into the environment”, although this is not included in their formal recommendations. This would suggest that masks worn by symptomatic patients
to prevent dissemination of infectious particles should be fluid resistant but this is based on interpretation and is not specifically outlined in any
sources and so has been given a level 4 (expert opinion) grading.
Respiratory droplet
Control:
Viral load (log10 virus
and respiratory
Leung N.H.L. et al.
Respiratory droplets
copies per sample)
aerosol samples were
Respiratory virus
and respiratory
detected in aerosol
collected for 30 mins
shedding in exhaled
aerosols samples were samples and droplet
Randomised
with participants
breath and efficacy of
1-
collected for 30 mins
samples.
controlled trial
wearing a type II
face masks. Nature
whilst they sat
mask whilst they sat
Medicine, 3 April
naturally breathing
Detection of virus in
naturally breathing
2020.
with allowance for
aerosol samples and
with allowance for
any natural coughing.
droplet samples.
any natural coughing.
Effect of wearing a surgical mask (equivalent to type II) on detection of viral seasonal influenza, seasonal coronavirus or seasonal rhinovirus
particles detected on exhalation from infected participants. Respiratory droplets or respiratory aerosols were collected for 30 mins with participants
either wearing or not wearing a mask whilst they sat naturally breathing with allowance for any natural coughing. Of 246 - 122 randomised to not
wearing a facemask, 124 randomised to wearing a facemask. Of 246 participants – 111 had seasonal coronavirus (n=17), influenza (n=43) or
rhinovirus (n=54). [3 participants had multiple infections].
No coronavirus virus was detected in respiratory droplets or aerosols collected from participants wearing face masks (n=11), this detection and viral
load difference was significant in aerosols (p=0.04). Surgical face masks significantly reduced detection and viral load of influenza virus RNA in
respiratory droplets. While not wearing a mask, viral RNA was only identified from 30% (corona), 26% (influ) and 28% (rhino) of respiratory
droplet samples and 40% (corona), 35%(influ) and 56% (rhino) of aerosol samples. Reduced detection of virus is an indirect measure of reduced
- 16 -
transmission from symptomatic patients.
Authors report that viable influenza particles were detected in aerosols following collection of samples from both those wearing and not wearing
masks highlighting this as a potential mode of transmission. Among the eight participants who had influenza virus detected by RT–PCR from
without-mask aerosols, five were tested by viral culture and four were culture-positive. Among the six participants who had influenza virus detected
by RT–PCR from with-mask aerosols, four were tested by viral culture and two were culture-positive.
It is unclear as to the impact that widespread use of this intervention would have, especially as it appears that a proportion of patients may not
exhale any detectable virus whilst infected.
This study suggests that type II surgical masks may significantly reduce coronavirus virus (exhaled from symptomatic mask wearers in the form of
droplets and/or aerosols) to undetectable levels. However, sample sizes are too small to draw definitive conclusions.
This study suggests that type II surgical masks may significantly reduce influenza virus (exhaled from symptomatic mask wearers in the form of
droplets). However, sample sizes are too small to draw definitive conclusions.
This study suggests that type II surgical masks may not be effective in significantly reducing rhinovirus virus (exhaled from symptomatic mask
wearers in the form of droplets and/or aerosols). However, sample sizes are too small to draw definitive conclusions.
This study suggests that type II surgical masks may not be effective in significantly reducing influenza virus (exhaled from symptomatic mask
wearers in the form of aerosols). However, sample sizes are too small to draw definitive conclusions.
This study is limited and provides very weak evidence that surgical face masks could be used by symptomatic people to reduce onwards
transmission of respiratory pathogens.
Ref XX. DoH and
HPA 2009.
PANDEMIC (H1N1)
2009 INFLUENZA
Guideline
4
A summary of
guidance for infection
control in healthcare
settings.
“The provision of surgical masks to patients with suspected or confirmed pandemic influenza to be worn from the point of assessment or triage in
- 17 -
any healthcare setting (except when in a dedicated influenza area) should be considered.”
“In common waiting areas or during transport, symptomatic patients may wear surgical masks to minimise the dispersal of respiratory secretions
and reduce environmental contamination.”
Health
Protection
Network
Considered judgement form
Question: When should patients wear a FRSM? (SICPs)
Evidence Table Ref: 6a
1. Volume of Evidence - Quantity of evidence on this topic and quality of method
- 18 -
1 low quality RCT which assesses the merit of patients wearing surgical masks during treatment of epistaxis
1 observational study which assesses the impact of immunocompromised patients wearing masks when being transported out with their rooms during
constructions periods.
2. Applicability – in Scotland
Applicable
3. Generalisability - How reasonable it is to generalise from the available evidence
Due to the low number of studies it would be inappropriate to generalise from the available evidence.
4. Consistency - Degree of consistency demonstrated by the available evidence
N/A
5. Potential Impact of the intervention
Asking patients to wear masks may be unnecessary, impact on pt comfort, inhibit communication and be a waste of resources if not required.
6. Other factors to consider while assessing the evidence base
7. Evidence Statement – synthesis of the evidence relating to this question
Evidence level
- 19 -
Scientific findings are limited and based on observational studies. Recommendations are based on expert opinion and the
concept that masks are low cost interventions therefore recommending their use may be based on a precautionary
approach
Leukaemia and bone marrow transplant patients, who are being transported out with their room, during a period of
3
hospital construction, should be given a surgical mask to wear if it can be tolerated.
As there is only one study to support each patient mask wearing event, conclusions and thus recommendations cannot
currently be drawn.
8. Recommendation -
Grade of Recommendation
No recommendations can currently be made regarding patients wearing surgical masks in line with SICPs.
N/A
Question: When should patients wear a FRSM? (TBPs)
Evidence Table Ref: 6b
1. Volume of Evidence - Quantity of evidence on this topic and quality of method
There is a paucity of evidence on when patients should wear surgical masks. However, there does appear to be some consensus between the Guidance
available from UK sources which focus on prevention of spreading of the aerosol or droplet infection whilst the patient is accessing communal areas (out of
their room).
1 systematic review was inconclusive regarding need for CF patients to wear surgical masks in communal areas (studies assessed were indirect measures of
infection control)
1 controlled experimental study suggested that masks can filter out/reduce influenza particles produced by infectious patients
1 piece of UK guidance (B) gave advice re mask wearing by TB patients
1 UK expert opinion/guidance (C), 2 x US expert opinion guidance (C), WHO guidance (B) and US guidance (B) gave advice re: mask wearing by patients
known or suspected to be infected with droplet transmitted pathogens.
2. Applicability – in Scotland
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Most studies are low quality, conducted in the US or experimental in nature. Expert opinion is partly derived from UK based authors.
3. Generalisability - How reasonable it is to generalise from the available evidence
Due to the low quality/experimental nature of the studies it is inappropriate to generalise from the available evidence.
4. Consistency - Degree of consistency demonstrated by the available evidence
Recommendations are limited but fairly consistent.
5. Potential Impact of the intervention
Asking patients to wear masks may be unnecessary, impact on comfort, inhibit communication and be a waste of resources if not required.
6. Other factors to consider while assessing the evidence base
7. Evidence Statement – synthesis of the evidence relating to this question
Evidence level
Scientific findings are limited and based on observational/experimental studies. Recommendations are based on expert
opinion and the concept that masks are low cost interventions therefore recommending their use may be based on
3/4
precautionary measures
8. Recommendation -
Grade of Recommendation
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If it can be tolerated, an FRSM may be worn by a patient known or suspected to be infected with a microorganism spread
by the droplet route during patient transportation from one clinical area to another.
Patients with pulmonary or laryngeal Tuberculosis should be made aware by the healthcare team caring for them that a
B/C
surgical mask should be worn when they leave their room and that this precaution applies until they have received a
minimum of 2 weeks of treatment (NICE 2016).
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