Nursing

diagnostics

Article

Self-Collected versus Healthcare Worker-Collected
Swabs in the Diagnosis of Severe Acute Respiratory
Syndrome Coronavirus 2

Johan H. Therchilsen 1,*, Christian von Buchwald 1, Anders Koch 2, Susanne Dam Nielsen 2,
Daniel B. Rasmussen 2, Rebekka Faber Thudium 2, Nikolai S. Kirkby 3,
Daniel E. T. Raaschou-Pedersen 4, Johan S. Bundgaard 4, Kasper Iversen 5, Henning Bundgaard 4

and Tobias Todsen 1,6

1 Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Rigshospitalet,
Copenhagen University Hospital, 2100 Copenhagen, Denmark; christian.von.buchwald@regionh.dk (C.v.B.);
tobiastodsen@gmail.com (T.T.)

2 Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital,
2100 Copenhagen, Denmark; Anders.Koch@regionh.dk (A.K.); susanne.dam.poulsen@regionh.dk (S.D.N.);
daniel.braeuner.rasmussen@regionh.dk (D.B.R.); rebekka.faber.thudium@regionh.dk (R.F.T.)

3 Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital,
2100 Copenhagen, Denmark; nikolai.kirkby@regionh.dk

4 Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, 2100 Copenhagen, Denmark;
daniel.raaschou@gmail.com (D.E.T.R.-P.); johan.bundgaard@gmail.com (J.S.B.);
Henning.bundgaar@regionh.dk (H.B.)

5 Department of Cardiology, Copenhagen University Hospital Herlev, 2730 Herlev, Denmark;
kasper.iversen@regionh.dk

6 Copenhagen Academy for Medical Education and Simulation, Rigshospitalet,
Copenhagen University Hospital, 2100 Copenhagen, Denmark

* Correspondence: johan.hindkjaer.therchilsen@regionh.dk; Tel.: +45-26250191

Received: 23 August 2020; Accepted: 7 September 2020; Published: 9 September 2020
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Abstract: The aim of this study was to compare the sensitivity of self-collected versus healthcare worker
(HCW)-collected swabs for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) testing.
Symptomatic individuals referred for SARS-CoV-2 testing were invited to provide mobile-phone
video-instructed self-collected oropharyngeal and nasal samples followed by a HCW-collected
oropharyngeal sample. All samples were sent for analysis to the same microbiology laboratory,
and the number of SARS-CoV-2-positive participants in the two tests was compared. A total of
109 participants were included, and 19 participants had SARS-CoV-2-positive results. The diagnostic
sensitivity of the self-collected and HCW-collected swabs was 84.2% and 89.5%, respectively, with an
acceptable agreement, Cohens kappa 0.82, p < 0.001. Further, results from a questionnaire answered by the participants found that loss of smell as a self-reported symptom was a strong predictor for a SARS-CoV-2-positive test. In conclusion, we found that self-collected oropharyngeal and nasal swabs for SARS-CoV-2 testing can be reliable compared to HCW-collected oropharyngeal samples.

Keywords: COVID-19; COVID-19 diagnostic testing; severe acute respiratory syndrome coronavirus 2

1. Introduction

A comprehensive Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) testing
strategy is recommended to quickly identify new cases and suppress local outbreaks during the current
coronavirus disease 2019 (COVID-19) pandemic. The WHO recommends a collecting technique for
upper respiratory samples to obtain oropharyngeal and nasopharyngeal samples, which is performed

Diagnostics 2020, 10, 678; doi:10.3390/diagnostics10090678 www.mdpi.com/journal/diagnostics

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Diagnostics 2020, 10, 678 2 of 10

by a healthcare worker (HCW) [1]. This approach has a high economic burden, reduces the number of
available HCWs for other tasks, increases depletion of personal protective equipment, and exposes the
HCWs to the risk of infection. Therefore, alternative methods for the collection of specimens for viral
analyses are desired [2]. Self-collected swabs may be a low-cost alternative to HCW-collected samples
for SARS-CoV-2 testing, as supported by earlier studies which found that self-collected samples are
reliable in testing for influenza virus [3–6]. Self-testing is now accepted as an initial diagnostic testing
method for SARS-CoV-2 by the National Health Service (NHS, United Kingdom) [7] and the Centers
for Disease Control and Prevention (CDC, USA) [8], even though data on the diagnostic accuracy of
self-collected swabs for SARS-CoV-2 testing are sparse [9–12]. The aim of this study was to explore
the correlation and diagnostic sensitivity of a simple low-cost technique for self-collected samples as
an alternative to the more burdensome method based on HCW-collected samples in the diagnosis of
SARS-CoV-2 in symptomatic individuals.

2. Methods

We performed a cross-sectional study to compare the diagnostic results when both self-collected
and HCW-collected swabs for SARS-CoV-2 testing were obtained from the same individuals with
symptoms indicative of COVID-19.

2.1. Setting and Eligibility Criteria

Eligible study participants were persons referred to the COVID-19 outpatient testing facility
at Copenhagen University Hospital Rigshospitalet, Denmark. Persons were referred by a general
practitioner because of mild symptoms compatible with COVID-19, for screening prior to an outpatient
appointment, or in relation to a planned hospital admission (e.g., surgery at the hospital). Further,
symptomatic HCWs employed at the hospital were also referred for COVID-19 testing at the facility.

In the period 5 May–1 July 2020, persons above 18 years of age attending the testing facility with
symptoms of upper respiratory tract infection were asked to participate in the study. There were
no exclusion criteria. In addition, to increase the number of SARS-CoV-2-positive patients in the
study, we also invited already confirmed SARS-CoV-2-positive patients to participate in the study.
These patients received a phone call informing them of their SARS-CoV-2-positive status from a
previous test. If they agreed, a new appointment for SARS-CoV-2 testing—as a part of the study—was
scheduled, i.e., within a few days following their initial SARS-CoV-2-positive sample, see Figure 1.

Diagnostics 2020, 10, x FOR PEER REVIEW 3 of 11

Figure 1. Study flowchart. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, GP,
general practitioner, HCW, healthcare worker.

2.2. Interventions

At arrival at the testing facility, persons referred for testing were informed about the study
verbally and in writing. After giving informed consent, those volunteering for the study provided a
self-collected sample and a HCW-collected sample. Self-collection of samples was done in a separate
room at the COVID-19 testing facility, where the study persons received written and Supplementary
Video S1 instructions. The two-minute long instructional Supplementary Video S1 was produced
specifically for the present study and demonstrated how to perform self-collection of an
oropharyngeal sample, using a mirror and the light from the person’s mobile phone, and of a nasal
(mid-turbinate) sample, using the same rigid shafted swab, with a hydroflocked tip (Zymo Collection
Swab, Zymo Research, Irvine, CA, USA), as shown in Figure 2.

Figure 1. Study flowchart. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, GP, general
practitioner, HCW, healthcare worker.

Diagnostics 2020, 10, 678 3 of 10

2.2. Interventions

At arrival at the testing facility, persons referred for testing were informed about the study verbally
and in writing. After giving informed consent, those volunteering for the study provided a self-collected
sample and a HCW-collected sample. Self-collection of samples was done in a separate room at the
COVID-19 testing facility, where the study persons received written and Supplementary Video S1
instructions. The two-minute long instructional Supplementary Video S1 was produced specifically
for the present study and demonstrated how to perform self-collection of an oropharyngeal sample,
using a mirror and the light from the person’s mobile phone, and of a nasal (mid-turbinate) sample,
using the same rigid shafted swab, with a hydroflocked tip (Zymo Collection Swab, Zymo Research,
Irvine, CA, USA), as shown in Figure 2.Diagnostics 2020, 10, x FOR PEER REVIEW 4 of 11

Figure 2. Screenshots from the Supplementary Video S1 demonstrating how to perform self-collection
of oropharyngeal and lower nasal samples with the use of a single swab for SARS-CoV-2 testing. Foto
1 shows the patient examining which nostril to use for collection the sample. Foto 2 shows collection
of oropharyngeal sample. Foto 3 shows depth of insertion to collect middle turbinate sample. Foto 4
shows the patient performing middle turbinate sample. For more information please consult with
Figure A1.

For the oropharyngeal sample, both the posterior wall of the oropharynx and one palatine tonsil
had to be sampled for the sampling technique to be considered correct; for the nasal sample and
correct mid-turbinate sampling, the swab had to be introduced for about 3 cm or till resistance was
met. The participants watched the Supplementary Video S1 on their own mobile phone and thereafter
performed the self-sampling directed by the written pictorial guide summarizing the steps in the
procedure (see Figure A1). Without providing any guidance, a HCW was present in the room
observing and registering possible sampling errors while the participants performed the self-
collecting swab procedure. Afterwards, a trained medical student collected an oropharyngeal sample
from the opposite tonsil and posterior wall of the oropharynx, according to the standard procedure
to obtain HCW-collected samples for SARS-CoV-2 testing in Denmark. The self-collected and HCW-
collected swabs were placed in individually labelled vials (eSwab Collection & Transport System,
Copan Italia SpA, Brescia, Italy) and stored at 4 °C until transportation to the Department of Clinical
Microbiology, Rigshospitalet, which performed all analyses of SARS-CoV-2 samples at the hospital.
At the completion of both swab collections, the participants were asked to complete a questionnaire
regarding their symptoms and an evaluation of the sampling procedures (see Figure A2).

Figure 2. Screenshots from the Supplementary Video S1 demonstrating how to perform self-collection
of oropharyngeal and lower nasal samples with the use of a single swab for SARS-CoV-2 testing. Foto 1
shows the patient examining which nostril to use for collection the sample. Foto 2 shows collection of
oropharyngeal sample. Foto 3 shows depth of insertion to collect middle turbinate sample. Foto 4 shows
the patient performing middle turbinate sample. For more information please consult with Figure A1.

For the oropharyngeal sample, both the posterior wall of the oropharynx and one palatine
tonsil had to be sampled for the sampling technique to be considered correct; for the nasal sample
and correct mid-turbinate sampling, the swab had to be introduced for about 3 cm or till resistance

Diagnostics 2020, 10, 678 4 of 10

was met. The participants watched the Supplementary Video S1 on their own mobile phone and
thereafter performed the self-sampling directed by the written pictorial guide summarizing the steps
in the procedure (see Figure A1). Without providing any guidance, a HCW was present in the room
observing and registering possible sampling errors while the participants performed the self-collecting
swab procedure. Afterwards, a trained medical student collected an oropharyngeal sample from the
opposite tonsil and posterior wall of the oropharynx, according to the standard procedure to obtain
HCW-collected samples for SARS-CoV-2 testing in Denmark. The self-collected and HCW-collected
swabs were placed in individually labelled vials (eSwab Collection & Transport System, Copan Italia
SpA, Brescia, Italy) and stored at 4 ◦C until transportation to the Department of Clinical Microbiology,
Rigshospitalet, which performed all analyses of SARS-CoV-2 samples at the hospital. At the completion
of both swab collections, the participants were asked to complete a questionnaire regarding their
symptoms and an evaluation of the sampling procedures (see Figure A2).

2.3. SARS-CoV-2 Real-Time Reverse-Transcription Polymerase Chain Reaction Testing

The swabs were processed as routine samples by clinical laboratory technicians blinded to the
sampling method. Samples were analyzed using the real-time reverse-transcription polymerase
chain reaction (rRT-PCR) assay, by using either the SARS-CoV-2 real-time RT-PCR test on the
Cobas 6800 system (Roche, Basel, Switzerland) or the RealStar® SARS-CoV-2 RT-PCR Kit (Altona,
Hamburg, Germany). In brief: the nucleic acids in the patient sample were extracted together with
an internal RNA control using magnetic silica particles and transferred to a specific RT-PCR assay,
targeting two separate gene segments.

2.4. Statistical Analysis

A true positive test result was defined as a SARS-CoV-2-positive result from either the self- or the
healthcare-collected sample. Intertest agreement between the self-collected and the HCW-collected
swabs was calculated using Cohen’s kappa (k). A k > 0.80 was considered an acceptable intertest
agreement [13]. The sensitivity of each test was calculated as the number of positive test/total number
of true positive patients for both the self- and the HCW-collected samples. Differences in group
characteristics were compared with the chi-square test for categorical variables and the Student’s
t-test for continuous variables; p-values were Bonferroni-corrected because of multiple statistical
testing. The statistical analysis was performed using a statistical software package (PASW, version 26.0;
SPSS Inc, Chicago, IL, USA), and two-sided significance levels of 0.05 were used for all analyses.

2.5. Ethics and Data Management

Ethical approval was granted in the form of an exemption letter from the regional ethical committee
of the Capital Region of Denmark (protocol no. H-20027981, approved on 24 April 2020), and the
Danish Data Protection Agency approved the management of patient-sensitive information during the
study (record number: P-2020-467). All participants gave verbal and written informed consent prior
to enrolment.

3. Results

A total of 109 participants were included in the study. Demographics of the participants and their
self-recorded symptoms are shown in Table 1.

Diagnostics 2020, 10, 678 5 of 10

Table 1. Clinical characteristics and self-recorded symptoms of the study participants.

All Participants
SARS-CoV-2

Negative
SARS-CoV-2

Positive
p Value

(Chi-Square)

Clinical characteristics

Number of participants 109 90 19

Sex, female–n (%) 76 (70%) 65 (72%) 11 (58%) 0.22

Mean age—years mean/median
(SD)

39 (13) 40.4 (13) 32.6 (5.9) 0.33

Healthcare education n (%) 26 (25%) 21 (23%) 6 (32%) 0.45

Median days since first symptoms
mean/median—(Range) IQR

3.0 (0–65) 3.0 (0–65) 7.0 (2–25) 0.10

Self-recorded Symptoms, n (%)

Fever 41 (38) 32 (36) 9 (47) 0.35

Cough 54 (50) 44 (49) 10 (53) 0.80

Lethargy 55 (50) 43 (48) 12 (63) 0.24

Throat pain 59 (54) 51 (57) 8 (42) 0.23

Headache 62 (57) 48 (53) 14 (74) 0.11

Respiratory problems 14 (13) 12 (13) 2 (11) 0.11

Loss of smell 18 (17) 8 (9) 10 (53) <0.001 *

Diarrhea 14 (13) 11 (12) 3 (16) 0.67

* p-value after Bonferroni correction.

Among the 109 participants, 19 patients had SARS-CoV-2-positive results from self-collected
samples, HCW-collected samples, or both. The proportion of SARS-CoV-2-positive samples was
16/109 (14.7%) for the self-collected samples in comparison to 17/109 (15.6%) for the HCW-collected
samples, as shown in Table 2. Acceptable agreement between self-collected and HCW-collected swabs
was found, Cohens kappa 0.82, p < 0.001, without any significant difference in diagnostic sensitivity for the self-collected and HCW-collected samples, corresponding to 84.2% and 89.5%, respectively, p = 0.81. However, of the 19 positive samples, only 14 (74%) were found positive by both tests. Combining the self-collected samples to the HCW-collected samples added two more SARS-CoV-2-positive cases out of the 109 included participants, who would otherwise have been tested as false negative using only the HCW-collected samples.

As to the preference of the swab technique, 47/109 (43.1%) of the participants preferred sample
self-collection, 29/109 (26.6%) preferred collection by HCWs, and 33/109 (30.3%) did not have any
preference. An error in the sampling technique by a participant was registered for 16/109 (14.7%) of the
self-collected oropharyngeal samples, 18/109 (16.5%) for nasal samples; 4/109 (3.7%) of the participants
made a double error. Six sampling errors were observed in the 19 SARS-CoV-2-positive patients,
including a double sampling error, and in 1/3 of the false negative participants, a sampling error for
the middle turbinate sample was observed. Discordant results favoring HCW collection regarded
primarily patients 20–25 days post-symptom onset. If inclusion of patients were limited to two weeks
post-symptom onset, then 14/14 self-collected vs. 13/14 HCW-collected samples would have been
positive for SARS-CoV-2. A subgroup analysis found that samples from participants with a healthcare
education detected SARS-CoV-2 in 5/6 (83%) of the true positive cases; a similar detection rate was
found for the participants without a healthcare education 11/13 (85%).

Loss of smell was the only self-recorded symptom that differed significantly between
SARS-CoV-2-positive and SARS-CoV-2-negative participants (53% versus 9%, p < 0.001) (Table 1).

Diagnostics 2020, 10, 678 6 of 10

Table 2. Samples positive for SARS-CoV-2 by sampling method.

Participant
(SARS-CoV-2
True Positive)

Time from
Self-Reported

Symptom Onset

Healthcare
Worker-Collected

Oropharyngeal Swab

Self-Collected Middle
Turbinate/Oropharyngeal Swab

1 8 Positive Positive
2 25 Positive Negative
3 12 Positive Positive
4 3 Positive Positive
5 2 Positive Positive
6 7 Positive Positive
7 9 Positive Positive
8 2 Positive Positive
9 5 Positive Positive

10 5 Negative Positive
11 25 Negative Positive
12 4 Positive Positive
13 3 Positive Positive
14 10 Positive Positive
15 17 Positive Positive
16 6 Positive Positive
17 20 Positive Negative
18 6 Positive Positive
19 23 Positive Negative

4. Discussion

We found that self-collection of sample swabs for SARS-CoV-2 testing is a well-tolerated diagnostic
method with a sensitivity almost equivalent to that of collection of oropharyngeal samples by HCWs.
A very good and significant intertest correlation was found between the diagnostic outcomes of
self-collected and HCW-collected samples, although we found a slightly lower sensitivity for the
self-collected samples compared with the HCW-collected ones. The sensitivity of 84.2% of the
self-collected samples is comparable to values found in other studies [9–11] and slightly higher than
that determined in a study from Washington, USA [12]. However, in the latter study, there was a delay
between the diagnostic tests and the shipping of the self-collected samples at room temperature from
participants’ homes, which could explain the observed difference [12]. A strength of our study is that
the self- and HCW-collected samples were obtained at the same time, which decreased the risk of
change of viral load between the tests. Further, all of the 218 (109 × 2) samples were stored in the
same type of transport medium and at the same temperature and analyzed at the same laboratory,
which increases the internal validity of our test results. We used a simple self-collection sampling
technique in this study, whereby all participants were guided by a mobile phone video-instruction,
and no HCW were needed for guidance. This could therefore increase the applicability of the method
using a single swab and a vial for self-testing.

Interestingly, the loss of smell was the only self-reported symptom for which a difference
was seen between SARS-CoV-2-positive and -negative participants. Approximately half of the
SARS-COV-2-positive participants reported a loss of smell compared to 9% of the SARS-COV-2-negative
participants, a result that is highly significant even after a Bonferroni correction for multiple statistical
testing. These findings are comparable with those of other studies describing olfactory loss associated
with SARS-CoV-2 infection [14,15]. Therefore, we recommend heightened awareness when patients
describe a sudden loss of smell, and it should be considered whether to offer them a test for SARS-CoV-2.

The findings of the present study should be interpreted in accordance to the following limitations.
We do not know the true SARS-CoV-2 infection status in our participants, as our results are

dependent on a positive HCW-collected and/or self-collected swab. We can therefore expect that some
of the participants will be false-negative, and a lower sensitivity of both tests may be expected. Further,
the HCW-collected and self-collected swabs were not performed in the same way, as the self-collection

Diagnostics 2020, 10, 678 7 of 10

technique also included the acquisition of a nasal sample in addition to the oropharyngeal sample.
However, as the study aim was to compare a new self-testing technique with the recommended
standard technique for SARS-CoV-2 testing in Denmark (HCW-collected oropharyngeal sample),
we chose this method. The small sample size of our study was without sufficient power to conduct
a non-inferiority statistical comparison of the sensitivity between HCW-collected and self-collected
samples for SARS-CoV-2 testing. A priori, we did not expect self-collected samples to be as sensitive as
HCW-collected, and we were surprised by the almost equivalent sensitivity of the self-collection- and
HCW-collection-based SARS-CoV-2 testing methods found in our study. These findings may be the
result of combined oropharyngeal and nasal sampling for the self-collected samples that were compared
to HCW-collected oropharyngeal swabs. In our study, we found two additional SARS-CoV-2-positive
patients—corresponding to an increase in sensitivity of 10%—by adding self-collected oropharyngeal
and nasal samples to HCW-collected oropharyngeal swabs. Assuming a similar sensitivity for the
self- and the HCW-collected samples, this emphasizes the importance of nasal samples in SARS-CoV-2
testing. These findings are also in accordance with a recent study that found a higher concentration of
SARS-CoV-2 RNA in nasopharyngeal samples than in oropharyngeal ones in SARS-CoV-2-positive
patients [16]. Another limitation is the presence of a high proportion of health professionals among
the participants, which may impact on the generalizability of our results. A lower sensitivity of the
self-collected swabs could be expected when the technique is introduced in the general community,
with older and fewer healthcare-educated patients. However, we found no difference in the proportion
of false-negative test results between participants with or without a healthcare education. Another
factor which might impact the sensitivity of the test method were it to be performed without a HCW’s
supervision is the patients’ personal situation. Some patients might have a social or economic interest
or a fear of a positive result.

In conclusion, we found an acceptable sensitivity for swab samples collected from the nasal and
oropharyngeal cavities for SARS-CoV-2 testing by patients solely guided by a written pictorial guide
and Supplementary Video S1 instructions on their mobile phone. The SARS-CoV-2 self-test described
here is therefore a reliable testing method with a low false-negative rate compared to the technique
based on HCW-collected swabs and might be used in community testing or settings where HCW
time and personal protective equipment need to be economized. Future studies should explore the
diagnostic accuracy and cost-effectiveness of this method when implemented in a larger and more
heterogenous cohort of patients tested for COVID-19.

Supplementary Materials: The instruction Supplementary Video S1 was constructed specifically for this study.
https://drive.google.com/file/d/1ch4At6pvYThB5qKz32PFUJ69aOUur2Wg/view?usp=drive_web.

Author Contributions: Conceptualization, T.T., H.B., and C.v.B.; methodology, T.T., H.B., J.H.T., and C.v.B.;
software, T.T., D.B.R., and J.S.B.; validation, J.H.T. and T.T.; formal analysis, J.H.T. and T.T.; investigation, J.H.T.,
D.E.T.R.-P., and R.F.T.; data curation, J.H.T.; writing—original draft preparation, J.H.T. and T.T.; writing—review
and editing, J.H.T., C.v.B., A.K., S.D.N., D.B.R., R.F.T., N.S.K., D.E.T.R.-P., J.S.B., K.I., H.B., and T.T.; project
administration, J.H.T.; funding acquisition, T.T. and J.H.T. All authors have read and agreed to the published
version of the manuscript.

Funding: This research received no external funding.

Conflicts of Interest: Swabs from Zymo Collection Swab, Zymo Research, Irvine, CA, USA were given free of
charge by Nordic Biosite, 1301 Copenhagen, Denmark. The funders had no role in the design of the study; in
the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish
the results.

https://drive.google.com/file/d/1ch4At6pvYThB5qKz32PFUJ69aOUur2Wg/view?usp=drive_web

Diagnostics 2020, 10, 678 8 of 10

Appendix A

Diagnostics 2020, 10, x FOR PEER REVIEW 9 of 11

Appendix A

Figure A1. Written Instructions.

Start by blowing your nose and examine

which nostril has the highest air flow.
Select this nostril for the nasal swab. If
the air flow is similar, choose the right
nostril.

Find a good light source, optionally your

phone. Light into your mouth while
looking at yourself in the mirror. Say
“ahh” to optimize your view.

Unscrew the lid on the transparent tube

and place it in a cup so the liquid doesn’t
run out. Unpack the bag containing the
swab stick.

You will now be able to view your palate
arches with your uvula hanging in the

middle. Furthest back is your pharynx
(*) and to both sides are your tonsils (*)
– where the swab shall be taken from.

(both * + * )

Now you are ready to the self-collecting
swab procedure.

Move the swab to the back wall of the
pharynx and avoid hitting the tongue or

the cheek on the way.

With the swab against the back wall of
the pharynx rotate the swab stick.

Repeat this procedure on one of your
tonsils with the same swab stick.

The same swab stick should now also be
used to take a sample from your nose.

Place two fingers 3-4 cm below the tip
of the swab stick in the cotton wool end.

Insert the swab stick into your nostril
until your fingers touch your nostril. The

swab stick is now 3-4 cm inside your
nose. Turn the swab stick around a
couple of times and take it out.

Put the cotton end of the swab into the
transparent tube and with the swab

stick in the tube break the swab stick
where it is indicated so you can screw
the lid on. Tighten the lid.

G uide to self-collected sw ab for C O VID -19

3)

4) 5) 6)

7) 8) 9)

S can and
view video

2) 1)

Figure A1. Written Instructions.

Diagnostics 2020, 10, 678 9 of 10
Diagnostics 2020, 10, x FOR PEER REVIEW 10 of 11

Figure A2. Questionnaire to the participants.

1. WHO Laboratory Testing for 2019 Novel Coronavirus (2019-nCoV) in Suspected Human Cases. Interim
Guidance. Available online: https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-
coronavirus-in-suspected-human-cases-20200117 (accessed on 17 January 2020).

2. Mohammadi, A.; Esmaeilzadeh, E.; Li, Y.; Bosch, R.J.; Li, J.Z. SARS-CoV-2 detection in different respiratory
sites: A systematic review and meta-analysis. EbioMedicine 2020, 102903, doi:10.1101/2020.05.14.20102038.

3. Dhiman, N.; Miller, R.M.; Finley, J.L.; Sztajnkrycer, M.D.; Nestler, D.M.; Boggust, A.J.; Jenkins, S.M.; Smith,
T.F.; Wilson, J.W.; Cockerill, F.R., III; et al. Effectiveness of patient-collected swabs for influenza testing.
Mayo Clin. Proc. 2012, 87, 548–554.

4. Seaman, C.P.; Tran, L.T.T.; Cowling, B.J.; Sullivan, S.G. Self-collected compared with professional-collected
swabbing in the diagnosis of influenza in symptomatic individuals: A meta-analysis and assessment of
validity. J. Clin. Virol. 2019, 118, 28–35.

5. Elliot, A.J.; Bermingham, A.; Charlett, A.; Lackenby, A.; Ellis, J.; Sadler, C.; Sebastianpillai, P.; Powers, C.;
Foord, D.; Povey, E.; et al. Self-Sampling for community respiratory illness: A new tool for national
virological surveillance. Eurosurveillance 2015, 20, 1–5.

6. Fisher, C.E.; Boeckh, M.; Jerome, K.R.; Englund, J.; Kuypers, J. Evaluating addition of self-collected throat
swabs to nasal swabs for respiratory virus detection. J. Clin. Virol. 2019, 115, 43–46.

7. Available online: https://www.gov.uk/guidance/coronavirus-covid-19-getting-tested#the-testing-process
(accessed on 28 July 2020).

8. Available online: https://www.cdc.gov/coronavirus/2019-ncov/lab/guidelines-clinical-specimens.html
(accessed on 28 July 2020).

9. Wehrhahn, M.C.; Robson, J.; Brown, S.; Bursle, E.; Byrne, S.; New, D.; Chong, S.; Newcombe, J.P.; Siversten,
T.; Hadlow, N. Self-collection: An appropriate alternative during the SARS-CoV-2 pandemic. J. Clin. Virol.
2020, 128, 104417.

10. Altamirano, J.; Govindarajan, P.; Blomkalns, A.L.; Kushner, L.E.; Stevens, B.A.; Pinsky, B.A.; Maldonado,
Y. Assessment of Sensitivity and Specificity of Patient-Collected Lower Nasal Specimens for Sudden Acute
Respiratory Syndrome Coronavirus 2 Testing. JAMA Netw. Open 2020, 3, e2012005.

Figure A2. Questionnaire to the participants.

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© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
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• Introduction
• Methods

Setting and Eligibility Criteria
Interventions
SARS-CoV-2 Real-Time Reverse-Transcription Polymerase Chain Reaction Testing
Statistical Analysis
Ethics and Data Management

• Results
• Discussion

References

Assignment

Review the results sections of the article you submitted, including tables and figures. Post the statistical results and interpret what each means. For example:

1. t-test was used to examine treatment a and treatment b. Results:  t = 3.5, p = .06. Interpretation is no difference between treatment a and b.

2. Pearson correlation used to examine relationship between treatment a and outcome b. Results: r = .85, p = .04. Interpretation is there is a positive relationship between treatment a and outcome b. 

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Can you help me with reviewing the results sections of this research article?

I have uploaded the research article that I submitted so you can read it to be able to best help me with the assignment.