JMIR FORMATIVE RESEARCH

Ahmed et al

Original Paper

New Heat and Moisture Exchangers for Laryngectomized Patientsin Germany: Mixed Methods Study on the Expected Effectiveness
Anam Ahmed, MSc; Janne C Mewes, PhD; Iris W A Boot, MSc; Hubertus J M Vrijhoef, PhD
Panaxea, Amsterdam, Netherlands

Corresponding Author:
Anam Ahmed, MSc
Panaxea
Science Park 400
Amsterdam, 1098 XH
Netherlands
Phone: 31 639421854
Email: anam.ahmed@panaxea.eu

Abstract
Background: Notwithstanding the benefits of heat and moisture exchangers (HMEs) in both clinical research and practice, agap exists between the optimal physiological humidification created through the nasal function and the humidification capacityof HMEs for patients after total laryngectomy. In this study, 5 new HMEs (Provox Life) specialized for situational use withimproved humidification capacities were evaluated.
Objective: This study aims to evaluate the effectiveness of the existing HMEs, assess the potential effectiveness of the new
HMEs, and elicit expert judgments on the new HMEs’ expected effectiveness and impact on health care use.
Methods: First, a rapid literature review (RLR) was performed to identify evidence on the clinical outcomes, health outcomes,
and complications of HMEs in patients who underwent laryngectomy. Second, semistructured interviews with German experts(n=4) were conducted to validate the findings of the RLR and identify reasonable expectations regarding the potential of the new
HMEs. Third, a structured expert elicitation among German experts (n=19) was used to generate quantitative evidence on the
expected effectiveness of the new HMEs in clinical and health outcomes.
Results: The RLR (n=10) demonstrated that HME use by patients has advantages compared with no HME use concerning
breathing resistance, tracheal dryness and irritation, mucus production and plugging, frequency of cough and forced expectorations,
sleep quality, voice quality, use of physiotherapy, tracheobronchitis or pneumonia episodes, quality of life, and patient satisfaction.
From the expert interviews and structured expert elicitation, it was found that, on average, experts expect that compared with thesecond-generation HMEs, the new HMEs will lead to a decrease in tracheal dryness or irritation (51%, SD 24%, of patients),
mucus plug events (33%, SD 32%, of patients), mucus production (53%, SD 22%, of patients), physiotherapy (0.74, SD 0.70,
days) and pulmonary infections (34%, SD 32%) and an increase or improvement in speech quality (25%, SD 23%, of patients),social contacts (13%, SD 18%), quality of life (33%, SD 30%), and patient satisfaction (44%, SD 30%). An improvement inbreathing (53%, SD 28%, of patients) and shortness of breath (48%, SD 25%, of patients) was expected. The average number ofdaily cough periods and forced expectorations was expected to be 2.95 (SD 1.61) and 2.46 (SD 1.42), respectively. Experts expect
that, on average, less than half of the patients will experience sleeping problems (48%, SD 22%) and psychosocial problems(24%, SD 20%).
Conclusions: According to German experts, it is expected that the new HMEs with improved humidification levels will leadto additional (clinical) effectiveness on pulmonary health and an improved overall quality of life of patients compared with thecurrently available HMEs.
(JMIR Form Res 2023;7:e36401) doi: 10.2196/36401
KEYWORDS
heat and moisture exchanger; HME; laryngectomy; device; laryngeal cancer; mixed methods; review; interview; structured expert
elicitation

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Introduction
BackgroundTotal laryngectomy (TL) involves the removal of the entire
larynx and redirection of the trachea to a neck stoma and is thelast surgical treatment option for patients with laryngeal cancer[1,2]. Besides the loss of laryngeal speech, many patients who
underwent TL face major pulmonary and other physical andpsychosocial postoperative problems, which can negatively
affect many health-related quality of life (HRQoL) aspects [3-9].
An important reason for these problems is the disconnection of
the upper and lower airways whereby the warming, humidifying,and filtering of inhaled air, before it reaches the pulmonary
tract, is no longer possible. Direct inhalation of (more) dry andcold air into the trachea causes pulmonary issues, such as
thickening and crusting of the mucus, overproduction of mucosal
secretions, and a reduction in the capacity of mucociliary
clearance. This leads to an increased need to clear the airway
from mucus by forced expectoration, increased involuntary
coughing, and shortness of breath [3-5,10]. Moreover, owing
to the loss of nasal filtering function and impaired mucociliary
clearance, patients who underwent TL have an increased riskof chronic airway inflammation and infections [11-13]. The useof heat and moisture exchangers (HMEs) by patients who
underwent TL reduces pulmonary problems. An HME helps by
providing stoma occlusion and compensates for the temperature,humidification, and filtering deficit [14-23]. Multiple studies
demonstrated the positive effects of HME use on pulmonary
rehabilitation and respiratory health in patients, especially whenadherence to HME use was high (ie, HME use day and night)[7,15,17,19,21,24-27]. High compliance to HME use has shown
positive effects and resulted in decreases in coughing or forced
expectorations in patients using HMEs day and night comparedwith less adherent users [17,28]. In addition, HMEs were foundto be cost-effective because of fewer postoperativecomplications requiring treatments [13,29]. Despite the benefitsof HMEs being clear in both clinical research and practice, agap exists between the optimal physiological humidificationlevel by the nasal function and the humidification capacity ofthe best HMEs [30]. It is challenging to bridge this gap, as anincrease in the humidification capacity of HMEs is constrictedby concurrent increases in breathing resistance and HME size.
Patient compliance to HME use is also considered an issue, anda large variation in compliance (35%-70%) has been observed[17,28,31]. Many patients experience issues related to thesituational use of HMEs, such as the breathing resistance being
too high during physical activity, insufficient protection against
airborne particles, and pulmonary problems at night [32]. Other
reasons for noncompliance are mainly linked to issues related
to peristomal adhesives (ie, skin irritation, poor attachment, andpoor fit to the stoma shape) [7,28,33]. In this light, new HMEs
have been developed focusing on improving HME performance(ie, providing the most optimal humidification possible while
keeping the breathing resistance comfortable), situational
usability, and HME attachments (improved security,
skin-friendliness, and fit). Improvements in these areas will
most likely positively influence patients’ HME compliance,
pulmonary health, and, ultimately, quality of life (QoL) [32].
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Ahmed et al

Goal of This StudyIn this study, the potential effectiveness of 5 new HMEs (ProvoxLife) manufactured by Atos Medical AB (Hörby, Sweden) was
evaluated. These new HMEs are also called the third-generation
HMEs, as they follow the first-generation (Provox HME) andthe second-generation (Provox XtraHMEs) HMEs withimproved humidification properties compared with thefirst-generation HMEs. The new third-generation Provox Life
HMEs include features that specialize them for situational use(ie, nighttime, home stay, moderate physical activity, highphysical activity, and extra protection or filtration) and offer a
range of attachments to suit individual patients’ needs. As
limited empirical data are available on the use of the new HMEs,
information on their expected effectiveness can be collected
through expert opinion [34]. An evaluation of the effectivenessof the existing HMEs formed the basis for the assessment of
the potential effectiveness of the new HMEs through expert
opinion. The objective of this study was 3-fold; we aimed to(1) evaluate the effectiveness of the existing HMEs, (2) assess
the potential effectiveness of the new HMEs among German
clinical experts, and (3) elicit German expert judgments in aquantitative manner on the new HMEs’ expected effectivenessand impact on health care use.

Methods
In this mixed methods study, we conducted (1) a rapid literature
review (RLR) on the effectiveness of the existing HMEs, (2)interviews with experts to validate the findings of the RLR and
identify reasonable expectations regarding the potential of the
new HMEs (Provox Life), and (3) a structured expert elicitation(SEE) to elicit experts’ judgments about the new HMEs’
effectiveness and impact on health care use.

Rapid Literature Review
An RLR, which provides knowledge synthesis in a timelier andresource-efficient manner, was conducted, as empirical data on
the new HMEs are limited and expert opinion is essential toassess the potential efficacy of the new HMEs as soon as
possible [35,36]. The search was conducted in PubMed. Articles
were included if they were clinical studies, randomized
controlled trials, reviews, or meta-analyses published between
January 2010 and February 2021 in English, Dutch, or German.
Articles needed to focus on identifying evidence on the clinicaloutcomes, health outcomes, and complications of HMEs inpatients who underwent TL. Articles were excluded if they wereconcerning in vitro and ex vivo studies. The search was
conducted in February 2021. The search string was as follows:((laryngectomy AND ((HME OR “Heat and Moisture
Exchanger” OR “Hygroscopic Condenser Humidifier”) OR(“Freehands HME”))) OR ((tracheostomy OR tracheotomy)
AND (HME OR “Heat and Moisture Exchanger” OR“Hygroscopic Condenser Humidifier”)) OR ((laryngectomy ORtracheostomy OR tracheotomy) AND HMEF). The titles andabstracts were screened independently by 2 authors (AA and
JCM). Full papers were retrieved if their titles and abstracts
were considered relevant. As for the full-text screening, theselection was done by one author (AA) and checked by a second
author (JCM). Disagreements were resolved by discussion,
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resulting in consensus. Data from each study were extractedusing a standardized data abstraction form by one author (AA)and checked by another author (JCM). The extracted data
included results on the effectiveness of HMEs in the outcome
measures breathing resistance, cough, forced expectoration,
tracheal dryness or irritation, mucus production or plugs, speechand voice quality, sleep quality, physiotherapy, pulmonary
infection, pneumonia episode, QoL, and patient satisfaction.

Expert Interviews
Semistructured interviews with experts were conducted tovalidate the findings of the literature review and identify
reasonable expectations regarding the potential of the new
HMEs for use in patients who underwent TL. Experts wereidentified by Atos Medical GmbH (Troisdorf, Germany), as
Germany is among the first countries to be introduced to the
new HMEs. Experts were approached by the authors by mail.
A total of 4 individual interviews were held with medical
specialists or senior physicians in the ear-nose-throat field witha focus on oncology and head and neck surgeons at leading
institutions in Germany. In this interview, the results of the RLR
were discussed for validation, and it was discussed whether the
new HMEs with better performance measured in the laboratory
would lead to additional effects compared with the currently
available HMEs. The following themes were included in theinterview: breathing resistance, mucus production or plugs,
tracheal dryness or irritation, cough and forced expectorations,
sleep quality, speech and voice quality, physiotherapy,
pulmonary infections (eg, tracheitis and tracheobronchitis),pneumonia episodes, psychological health, participation insociety, QoL, patient satisfaction, and compliance (with HMEuse). An interview protocol (Multimedia Appendix 1) was
prepared, including a brief introduction, an explanation of theresearch study, the process to be followed during the interview,the main questions, additional follow-up questions, and a final
thank you statement. Experts were also introduced to
information on the new HMEs (need for development of new
HMEs, innovative adaptions made to the new HME devices,the different HMEs included in the new portfolio, and laboratory
measurements concerning humidification and breathability of
the new HMEs in comparison with their predecessors). The
semistructured web-based interviews lasted 60 minutes on
average. One independent author (AA) conducted all interviewsin March and April 2021, and a second independent author(JCM) took notes during the interviews. Both authors are trainedand experienced interviewers. The interviews werevideorecorded and transcribed manually. Text segments wereassigned a code if they were related to a specific theme, using
an inductive, iterative process. The codes were based on thethemes included in the interviews. The interviews were analyzed(AA and JCM) based on their themes to gain an insight into theadditional effect of the new HMEs (content analysis).

Structured Expert Elicitation
SEE is a process that allows experts to express their judgment
in a statistical and quantitative form. SEE was used to estimate
the effectiveness of the new HMEs in health care use. The
process consisted of the following steps: selection of experts,
characterization of effect measures (ie, effects and use), defining
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Ahmed et alof the scope and format of the elicitation, design of theelicitation protocol, preparation of the elicitation session,elicitation of expert judgments, and data analysis [34]. First,
based on the RLR and expert interviews, information on theeffect variables of HMEs that are currently being used wascollected, which was included in the survey. A survey was set
up according to the bins and chips method (IWAB and HJMV).
In this method, experts were asked to indicate the lower andupper limits of their estimation of a specific effect variable (eg,difficulties with breathing) [37]. Experts assigned weights(0-100) to the effect variable to indicate the weight of theireffect estimate in different intervals (0-10, 11-20, 21-30, etc).
The stronger the expert believed that a specific effect lies in agiven interval, the greater the weight for that interval was. This
provides an estimated effect distribution (a mean effect andspread). For every expert judgment on each effect variable, amean was calculated. Subsequently, the sample mean was
calculated, which indicated the estimation of all expert
judgments combined. For the analysis, we multiplied the weightby the average of the intervals. Thereafter, the sum of theseoutcomes was divided by the total weights assigned by theexperts. In this manner, a weighted average per expert wasestablished. The sum of all weighted averages of experts wasaveraged, and the corresponding SDs were calculated, resulting
in our final indicator of experts’ beliefs. For some effectvariables, the experts were asked to indicate the lower and upper
limits of their estimation in absolute numbers. For these effectvariables, the last category would not be a set interval (eg,60-70), but it ended with a category “equal or more than X (i.e.,≥X).” In cases where an expert could be pointing at an amounthigher than X, the assigned weight was multiplied by X + 1
interval. An example of a question with fictional answers isprovided in Multimedia Appendix 2. The participants were sent
the electronic survey contained in Multimedia Appendix 3 (Atos
Medical, unpublished data, 2021, [12,16,28,29,31,38-44]) via
a web link (SurveyMonkey, Momentive Inc). German experts
were identified by Atos Medical GmbH and approached by anindependent author (IWAB) via mail, including the 4 experts
interviewed in the previous step of this study. Before
participating in the web-based survey, the experts were required
to read a white paper on the new HMEs and their developmental
background and watch a video presentation about the new
HMEs’ product portfolio to provide information on theproperties of the new HMEs. If the experts did not read thewhite paper and watch the video presentation and were,
therefore, assumed to have no basic knowledge of the new
HMEs, they could not take part in the survey. The survey started
with 6 general questions regarding current profession, years ofexperience in caring for patients with laryngeal cancer, yearsof experience in caring for patients who underwent TL, yearsof experience in prescribing and/or monitoring the use of HMEs,
years of experience as a scientific researcher in the field of
laryngeal cancer, and whether they had prescribed the new
HMEs. The experts were also asked whether they had read thewhite paper on the new HMEs and watched the video on the
new HMEs. The survey contained 16 other questions about thefollowing effect variables: breathing, shortness of breath,tracheal climate (n=2), mucus production or plugging (n=2),
coughing, forced expectorations, sleep quality, speech quality,
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psychological aspects, physiotherapy, tracheobronchitis or
pneumonia episodes, social contacts, QoL, and patientsatisfaction. At the end of the questionnaire, the participants
could provide general comments or remarks. The participants
were given 1 week to complete the questionnaire. After 1 week,
a reminder email was sent to complete the questionnaire withina week. The analysis was conducted by 1 author (IWAB) andchecked by 2 other authors (AA and HJMV).

Ethics Approval
As this study did not involve patients or study participants, anethical research approval was not needed according to Article
1b of the Dutch Medical Research in Human Subjects Act [45].
Notwithstanding, all the participants provided their consent,
and all the data were processed anonymously. The participants
could withdraw from the study at any time without any
consequences. The participants were financially compensatedfor their input in the SEE questionnaire.

Results
RLR Results
A total of 62 publications were identified in PubMed. Afterscreening the titles and abstracts of these studies, the full textof 38 (61%) of them were assessed. Of these 38 studies, 10(16%) were included in the analysis. In total, 3 (30%)
randomized controlled trials [28,29,40], 3 (30%) time-series
studies in which patients acted as their own controls [31,41,42],
1 (10%) retrospective comparative cohort study [43], 1 (10%)
retrospective clinical and survey study [12], 1 (10%) multigroup
design study (study design was not reported by the authors
themselves) [16], and 1 (10%) case-control study [44] were
included. The new generation of HMEs were compared with acontrol (no HME use) [12,16,28,39-41], an external humidifier[29,43,44], or a previous generation HME [31]. The studies
were performed in 7 different countries, namely the UnitedStates [16,43], Canada [44], France [29,40], Italy [41,42], Spain[31], the Netherlands [12], and Poland [28]. The studies included
a total of 550 patients, with a minimum of 30 patients [41,42]
and a maximum of 89 patients [12].

Effects of HMEs
In Table 1, the effects reported by these studies are shown.
Breathing was equal or less strenuous for HME users whencompared with the control group [41]. A statistically

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Ahmed et al
nonsignificant effect with regard to breathing effort wasachieved in 1 (10%) study [40]. Patients also reported astatistically significant decrease in shortness of breath [28,42].
However, 1 (10%) study reported a higher shortness of breath[16]. No difference was experienced in breathing resistancecompared with a previous generation HME device [31].
Moreover, improvements in the tracheal climate were observed,
as patients experienced significantly less tracheal dryness orirritation when using an HME [41,42] or when using an HME
with improved humidification capacities [31]. Studies also
reported statistically significantly lower mucus production anda lower rate of mucus plugging in patients who used an HME[42-44]. A statistically nonsignificant improvement wasobserved in mucus production compared with a control [41] orwhen using an HME with better humidification capacities [31].
Statistically significant effects of HME use also included asignificant decrease in coughing (episodes) [28,29,40,42] anddaily forced expectorations [28,29,42]; 2 (20%) studies reported
a statistically nonsignificant difference in the number of coughs
or forced expectorations when compared with a previous
generation HME [31] or a control [41]. Moreover, HME use
has been linked to statistically significant improvements insleep, as patients experience fewer sleep disturbances [29,42].
However, 4 (40%) studies reported no statistically significant
difference in sleep quality [16,28,31,44]. A statisticallysignificant improvement in speech quality was observed in
HME-compliant patients [42]. A statistically nonsignificant
improvement in voice quality was found in patients using HME[16,28,31,40]. One (10%) of the studies reported a statisticallysignificant difference in psychological stress [42], whereas in
the other studies, patients reported no differences in psychosocial
aspects [16,28,31]. HME use also significantly reduced thenumber of days requiring physiotherapy after surgery [44]. The
number of tracheobronchitis or pneumonia episodes per patient
per year in non-HME users was statistically significantly higher
than that in HME users [12]. When using a hands-free device,
patients have statistically significantly more frequent social
contacts [16]. One (10%) of the studies reported a statisticallynonsignificant improvement in social contacts [42]. The QoLof patients who underwent laryngectomy statisticallysignificantly increased in 1 (10%) study [42] but not in the otherstudy that examined this [40]. A statistically significant increasein patient satisfaction was observed in 1 (10%) study [29], anda statistically nonsignificant difference was observed in 2 (20%)
studies [41,42].

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Table 1. Overview of the effects of heat and moisture exchangers (HMEs) as reported in the included studies.
Effect variables and resultsa

References

BreathingAfter 12 weeks of using an HME, only 1 patient (3.4%) found it more difficult to breathe through the HME, 7 patients(24.1%) felt no difference, and 21 (72.4%) patients found breathing through the HME less difficult (P=.002).

Macri et al [41],2016

At 6 weeks, 71% of the patients and at 3 months, 88% of the patients responded positively to the question “Are you
breathing better?”.

Dassonville et al[40], 2011

Shortness of breath
A statistically significant decrease in shortness of breath was demonstrated with a baseline value of 5.7 and a value of 3.8 Parrilla et al [42],after 6 and 12 weeks of Provox XtraHME (P<.0001) using structured questionnaires.
2015
Both the HME users and the no-HME control group experienced a decrease in shortness of breath at rest (HME group:
P=.03; control group: P=.006). The HME users also experienced a significant increase in shortness of breath while
climbing steps (P=.012).

Bień et al [28], 2010

In total, 35% of the patients experienced lower breathing resistance with the first-generation HMEs, 25% experienced
lower breathing resistance with the second-generation HMEs, and 40% experienced no difference between the 2 devices(P=.41).

Herranz et al [31],2013

Non-HME users, Provox Micron HMEs users (first generation), and Provox HME (first generation) users scored a 4.6,
4.9, and 4.3, respectively, on the Quality-of-Life Questionnaire (P=.363).

Brook et al [16],2013

After 12 weeks of Provox XtraHME (second generation) use, 3.4% of the patients found it more difficult to breathe through Macri et al [41],the HME, 24.1% of the patients felt no difference, and 72.4% of the patients found breathing through the HME less difficult 2016
(P=.002).
Tracheal climate
After 2 weeks of Provox XtraHME (second generation) use, 60% of the patients reported less tracheal dryness or irritation Parrilla et al [42],and 40% reported no changes, compared with no HME use at baseline. After 12 weeks, 82.8% of the patients reported
2015
less irritation, 13.8% reported no changes, and 3.4% reported more irritation (P=.013).
After 12 weeks, 82.8% of the HME-using patients reported less irritation, 13.8% reported no changes, and 3.4% reported Macri et al [41],more irritation (P=.013).
2016
Patients reported significantly less tracheal dryness with the second-generation HMEs (38%) than with the first-generation Herranz et al [31],
HMEs (14%) (P=.039). Moreover, 42.5% of the patients preferred the second-generation HMEs, 40% preferred the first- 2013
generation HMEs, and 17.5% had no preference.
Mucus production or plugging
The rate of mucus plugging was significantly lower in the XtraHME group than in the EHb group (0.13 and 0.38 per 10 Ebersole et al [43],inpatient days, respectively, P=.02). The proportion of patients with ≥1 mucus plug events was also significantly reduced 2020in the HME group (50% in the EH group and 11% in the HME group, P=.01) in the postoperative period.
After 2 weeks of Provox XtraHME (second generation) use, there was statistically significantly less mucus production in Parrilla et al [42],patients.
2015
Of those experiencing mucus plugging, 12.5% had used an HME, in contrast to 87.5% who used an EH. There was a sig- Foreman et al [44],nificant difference between case and control groups based on use of an HME (χ2=9.4, P=.002). The odds ratio of a mucus 2016plug event when not using HME was 8.27.
After 12 weeks of use, 36% of the patients reported less mucus production with the first-generation HME, 26% reported
less mucus production with the second-generation HME, and 41% reported no difference (P=.162).

Herranz et al [31],2013

After 12 weeks of Provox XtraHME use, 79.3% of the patients reported less mucus production, 6.9% reported more mucus Macri et al [41],production, and 13.8% reported the same mucus production (P=.368).
2016
Coughing
At baseline (control) and after 2, 6, and 12 weeks of XtraHME use, the average number of daily coughs was 8.8, 4.6, 3.5, Parrilla et al [42],and 2.4, respectively (P<.001). After 2 weeks of HME use, the patients reported less coughing (63.3%) compared with2015
the baseline phase. After 6 and 12 weeks of HME use, the patients did not report any further change in coughing (P=.337).
At 3 months, there was a significant decrease in coughing in the HME group versus the no-HME control group (P=.00174). Dassonville et al
By means of an analog scale ranging from 0 to 10, the baseline value was 4, and after 2 months, this value dropped to 2. [40], 2011
A decrease was observed in the frequency of coughing in the HME group (P<.001). In the control group, the frequency
of coughing in week 1 was 60 times and in week 12, 56 times. In the HME group, this was 48 and 30, respectively.

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Bień et al [28], 2010

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Effect variables and resultsa

References

The number of coughing episodes were significantly lower in the HME arm (P<.001). In the EH group, 73% of the patients Mérol et al [29],had 2 to 10 spontaneous coughing episodes per day, whereas 8% had 20, another 8% had 30, and 4% had 72 episodes a2012
day (for 8%, this information was missing). In the HME group, most patients (90%) had 1 to 5 spontaneous coughing
episodes per day, whereas 4.3% had 10 and another 4.3% had 20 such episodes per day.
After 2 weeks of HME use, 63.3% of the patients reported less coughing compared with the baseline period. After 6 and
12 weeks of HME use, 83.3% and 89.7% of the patients, respectively, did not reported any further change in coughing(P=.337).

Macri et al [41],2016

The combined number of coughs and forced expectorations using the first- and second-generation HMEs was similar
Herranz et al [31],(P=.304). The average daily coughing frequency was lower when using the second-generation HMEs (2.0 vs 2.59 per
2013day). Most patients (51%) felt no difference between the 2 HMEs (P=.275) or reported that the second-generation HMEs
performed better (35% vs 22%).
Forced expectorations
A significant decrease in forced expectoration was reported in the XtraHME (second generation) group versus the control Parrilla et al [42],group (P<.0001). At baseline (control) and after 2, 6, and 12 weeks of Provox XtraHME use, the average number of daily 2015
forced expectorations was 6.3, 3.0, 2.3, and 1.9, respectively.
A decrease in the frequency of forced expectorations (P<.001) was found in the HME group compared with the control
group. In the control group, the frequency of forced expectorations in week 1 was 59 and in week 12, 53. In the HME
group, this was 56 and 27, respectively.

Bień et al [28], 2010

The frequency of mucus expectoration for clearing the trachea was significantly lower in the HME arm (P<.001). In the Mérol et al [29],EH group, the mean frequency of mucus expectoration was 5.5 times per day and in the HME group (first generation), 2.5 2012
times per day.
The combined number of coughs and forced expectorations using the first- and second-generation HMEs was similar
Herranz et al [31],(P=.304 and P=.764, respectively). The maximum number of forced expectorations was lower using the second-generation 2013
HME (12 vs 20 times per day). In total, 47% experienced no difference between the 2 generation HMEs, 23% experienced
less forced expectoration with the first-generation HMEs, and 30% experienced less forced expectoration with the secondgeneration HMEs (P=.513).
Sleep quality
A statistically significant improvement in sleep quality with a baseline value of 7.1 and a value of 6.2 (a lower score indicates Parrilla et al [42],less burden for the patient) after 12 weeks of Provox XtraHME use (P=.004) was reported in the structured questionnaires. 2015
Sleeping disturbances were significantly lower in the HME group (P<.001): 83% of patients in the HME group arm did Mérol et al [29],not experience any sleeping discomfort over the hospitalization period, whereas 17% mentioned some sleeping discomfort. 2012
No significant difference was reported between the HME group and EH group in sleep quality.

Foreman et al [44],2016

Patients did not report a difference in sleeping when using the first- or second-generation HME (72%).

Herranz et al [31],2013

In the control group, almost all the patients (97.5%) had sleeping problems, and this did not change over time. In the full- Bień et al [28], 2010
compliance HME group (first generation), 79% of the patients had sleeping problems at baseline, and 72% had this problem
after 3 months of HME use. This reduction was not significant.
Non-HME users, Provox Micron HMEs users, and Provox HME users scored a 4.5, 4.8, and 4.6, respectively, on the
Quality-of-Life Questionnaire (P=.913).

Brook et al [16],2013

Speech quality
A statistically significant improvement in speech quality, with a baseline value of 12.3 versus 10.3 after 12 weeks of Provox Parrilla et al [42],XtraHME (P<.0001) use, was reported in the structured questionnaires (a lower score indicates a lower burden for the2015
patient).
At 6 weeks, 80% of the patients experienced a statistically nonsignificant improvement in stoma occlusion with more
Dassonville et al
powerful and more audible phonation. At 3 months, this number rose to 94%. At 6 weeks, 52% of the patients using a[40], 2011
voice implant and an HME showed an improvement in the intensity of the prosthetic voice, and at 3 months, this value
increased to 71% (>5 on the analog scale). Regarding the fluency of speech, 62% of the patients experienced a nonsignificant improvement after 6 weeks of HME use, which increased to 76% after 3 months. Moreover, 71% of the patients had
perceived vocal improvement at 6 weeks, and 81% had perceived vocal improvement at 3 months.
The HME users and Micron users reported a better voice than did the non-HME users (not statistically significant). Non- Brook et al [16],HME users, Provox Micron HMEs users, and Provox HME users scored a 7.6, 9.4, and 8.0, respectively, on the Quality- 2013
of-Life Questionnaire (P=.396).
No significant change was reported in voice and speech aspects over time in the control and HME group. A trend was seen Bień et al [28], 2010
for the prosthetic speakers to report more fluent speech with HME use (P=.073).

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Effect variables and resultsa

References

After 6 weeks of use, no difference was reported in speech intelligibility and voice (72%, P=.739) between Provox HME Herranz et al [31],(first generation) and Provox XtraHME (second generation) users.
2013
Psychosocial aspects
Patients reported no differences concerning psychosocial aspects. Among both patients using the first-generation HMEs
and those using the second-generation HMEs, over 75% reported to have no problems, socially or psychologically.

Herranz et al [31],2013

At baseline, most patients (80%-90%) reported no or only slight problems with anxiety and depression, which had signif- Bień et al [28], 2010
icantly increased in the control group (no HME use; P=.003); however, in the HME groups (first generation), no significant
changes were found.
A statistically significant improvement in psychological stress, with a baseline value of 7.1 versus a value of 5.1 after 12
weeks of Provox XtraHME use (P<.001), was reported in the structured questionnaires (a lower score means less burden
for the patient).

Parrilla et al [42],2015

Non-HME users, Provox Micron HMEs users, and Provox HME users scored a 5.8, 6.5, and 6.6, respectively, on the
Quality-of-Life Questionnaire (P=.688).

Brook et al [16],2013

Physiotherapy
The use of Provox XtraHME significantly reduced the number of days requiring chest physiotherapy after surgery (1.75
vs 3.20 days, P=.034) compared with the use of EH.

Foreman et al [44],2016

Tracheobronchitis or pneumonia episodes
Among the non-HME users, 0.285 tracheobronchitis or pneumonia episodes was reported per patient per year, which was van den Boer et al
statistically higher than the 0.066 episodes reported per patient per year among the HME users (first generation; P=.047). [12], 2014
Among the non-HME users, an average of 0.129 pulmonary infections (tracheobronchitis and pneumonia together) was
documented per patient per year. Among the HME users (first generation), this average was 0.092 per patient per year
(P=.33).
Social contacts
Patients who use a Provox FreeHands device tended to have more frequent social contacts (r=0.251; P=.030).

Brook et al [16],2013

A statistically nonsignificant improvement in social contacts, with a baseline value of 8.1 versus a value 8.3 after 12 weeks Parrilla et al [42],(P=.728), was reported in the structured questionnaires when comparing no HME use with HME (second generation) use. 2015
Non-HME users, Provox Micron HME (first generation) users, and Provox HME (first generation) users scored a 9.6, 8.4, Brook et al [16],and 9.7, respectively, on the frequency of social contacts category from the Quality-of-Life Questionnaire (P=.438; a2013higher score indicates more problems).
QoLc
The EQ-5D Index showed an increase throughout the study, with an increase from an average of 0.84 at baseline to 0.96
after 12 weeks of HME use (P<.001). The EQ-5D VASd scale showed an increase from 61.3 at baseline to 80.0 after 12
weeks of Provox XtraHME use (P<.0001).
Among 60 patients, who were randomized between a control group that used no device and a group equipped with the
Provox HME (first generation), 92% of the patients with the device perceived an improvement in their QoL at the end of
3 months (>5 on the analog scale).

Parrilla et al [42],2015

Dassonville et al[40], 2011

Patient satisfaction
Patients’ satisfaction showed a significant improvement of first-generation HME over EH (P<.001). Patient satisfaction
Mérol et al [29],with the EH was quite low: 11% of the patients reported that they were satisfied with it, 8% reported they somewhat liked 2012
it, and 81% reported that they did not like it. All the patients (100%) in the HME (first generation) group were satisfied
with the device.
After 12 weeks of use, 60.7% of the patients were “very satisfied” with the use of the HME (first generation), and 39.3% Macri et al [41],were “satisfied.” None of the patients was dissatisfied with XtraHME (second generation).
2016a

A P value is presented if reported in the paper.

b

EH: external humidifier.

c

QoL: quality of life.

d

VAS: visual analog scale.

Expert Interviews
All 4 experts stated that they would expect the use of the new
HMEs to lead to improved outcomes compared with the use of
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the current HMEs. Because the optimized breathing resistanceadapted to different situations while also maintaining highhumidification levels by the HMEs of the new portfolio, it islikely that patients will tend to use the HME more often. One
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JMIR FORMATIVE RESEARCHof the experts stated that “a better product that has significant
benefits for the patient would lead to a higher compliance(participant 1).” All 4 experts were convinced that improved
humidification, breathability, and situational usability together
with improved HME attachments will lead to an optimized
breathing experience with limited shortness of breath. One of
the experts interviewed said that “if you change some problems
in current available HMEs like humidity and breathing
resistance, probably the compliance will increase (participant2).” All the experts pointed out that with a better performanceon the humidification and breathing resistance ratio, the tracheal
climate would improve, as this leads to higher humidificationand improved temperature. Experts indicated that they expectthat when using the new HME, patients will experience lessirritation when inhaling cold or dry air or small particles. A
better HME with increased humidification levels will also reduce
excess mucus and mucus plugs, (involuntary) coughing, andforced expectorations. Consequently, the sleep quality will get
improved. The new HMEs would prevent patients from having
dry and hard sticky mucus, which often needs to be removed
mechanically with a forceps. Moreover, complications such asa reduced diameter of the trachea due to mucus obstruction
affecting the trachea’s functionality were expected to occur lessfrequently. By preventing these complications, patients are
expected to experience breathing problems less often. There
was a consensus among experts that because of the larger
positive effects of the new HMEs compared with current HMEs
and higher adherence to HME use, the rates of inflammationand infection (eg, tracheitis, tracheobronchitis, and pneumonia
episodes) will decrease, resulting in reduced care consumption

Ahmed et alby the patient (eg, fewer hospital readmissions) and, thus,
reduced health care costs. One of the experts mentioned thatthe “length of hospital stay, if even it happened, will be less,because people get better and hospital readmission will probably
even decrease (participant 1)”. An overall improvement inpulmonary health because of the use of the new HMEs will leadto an increase in the HRQoL and satisfaction of the patient. In
turn, this will lead to an improved psychological health in thepatient. Patients who can cope well with coughing and othersymptoms feel confident to participate in social activities.
Improvements in all these domains will contribute to a higher
participation of the patient in society, and for patients of working
age, these increase the chances of returning to work. This would
entail patients having more social contact. Even though one of
the experts mentioned that “voice quality is one of the mostimportant things for patients with laryngectomy, (participant3)” overall, the experts did not expect to see any effects of using
the new HMEs on speech, voice quality, or the requirement ofphysiotherapy.
In Figure 1, the statements in the upper boxes (orange part) arebased on laboratory measurements, patient-reported outcomes,
and user evaluations of the new-generation HMEs, which resultin the box in the blue part. The boxes in the pink layer containthe effects of using HMEs, which the experts believe will further
improve when using the new-generation HMEs, resulting in theoutcomes given in the boxes in the green part. The causal
relationships among the effects in the pink section were notexplicitly discussed with the experts; however, they indicatedthat the effects were all related to each other.

Figure 1. Expected outcomes of the new improved heat and moisture exchangers (HMEs) according to the experts. HRQoL: health-related quality oflife.

Structured Expert Elicitation
A total of 24 German experts were invited to participate in a
web-based survey. Of those invited, 21 (88%) experts agreed
to participate, of whom 19 (90%) completed the survey. These
participants were head and neck surgeons (n=11, 58%),
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otolaryngologists (n=3, 16%), and speech therapists (n=5, 26%).
A total of 15 (79%) experts had heard about the new HMEs
before but had never prescribed them, whereas 4 (21%) experts
had prescribed the new HMEs at least once. Experts had an
average of 18.00 (SD 7.86) years of experience with providing
care to patients with laryngeal cancer, 17.32 (SD 8.09) years
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JMIR FORMATIVE RESEARCH
with providing care to patients who underwent TL, 13.05 (SD5.85) years with prescribing and/or monitoring the use of HMEs,
and 7.95 (SD 9.06) years as a scientific researcher in the fieldof laryngeal cancer.
The average expert judgments are listed in Table 2 (refer toMultimedia Appendix 4 for the average scores per interval).
Experts believed that, on average, 51% (SD 24%) of patients
will experience a decrease in tracheal dryness or irritation whencomparing the use of the new HMEs to a previous generation
HME after 12 weeks of use. An average decrease of 33% (SD32%) was expected in patients experiencing mucus plug events
when using the new HMEs compared with patients using
second-generation HMEs in the postoperative period. It was
expected that after 12 weeks of using the new HMEs, 53% (SD22%) of patients will have decreased mucus production
compared with no HME use. On average, 25% (SD 23%) ofpatients were expected to have better speech quality after 12
weeks of using the new HMEs compared with using thesecond-generation HMEs. An average decrease of 0.74 days
(SD 0.70) in the number of days requiring chest physiotherapy
was expected in patients using the new HMEs, compared withthose using second-generation HMEs, after 12 weeks, and thesepatients were also expected to experience an average decrease

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Ahmed et alof 34% (SD 32%) in pulmonary infections on a yearly basis.
After 12 weeks of HME use, an average increase of 13% (SD18%) in the number of social contacts and 33% (SD 30%) in
overall QoL were expected in patients using the new HMEs
compared with those using the second-generation HMEs. The
use of the new HMEs was expected to result in 44% (SD 30%)of patients being more satisfied with their HME when comparedwith patients using the second-generation HMEs after 12 weeks.
Experts expected an average of 53% (SD 28%) of patientsbreathing better after 12 weeks of using the new HMEs, and,on average, 48% (SD 25%) of patients were expected toexperience a decrease in shortness of breath after 12 weeks ofusing the new HMEs. Experts believed that, on average, 59%(SD 19%) of patients will experience a decrease in tracheal
dryness or irritation after 12 weeks of using the new HMEs.
The average number of daily coughs after 12 weeks of using
the new HMEs was expected to be 2.95 (SD 1.61) per patient,and the number of daily forced expectorations per patient after
12 weeks of new HME use was expected to be 2.46 (SD 1.42).
Experts indicated that 48% (SD 22%) of patients will experience
sleeping problems after 12 weeks of using the new HMEs. On
average, 24% (SD 20%) of the patients were expected toexperience psychosocial problems after 12 weeks of using the
new HMEs.

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Table 2. Average scores of expert judgments per effect variable.
Variables

Average scores (SD) Experts (n=19), SEEa processn (%)

Tracheal climate

1.51 (0.24)

19 (100)

In total, 51% of patients will experience a decrease in tracheal dryness or irritation when using the new HMEsb compared with second-generation HMEs
after 12 weeks.

aMucus plugging

0.67 (0.32)

19 (100)

The percentage of decrease in patients experiencing mucus plug events whenusing the new HMEs compared with using the second-generation HMEs during
the acute postoperative period (2 weeks) will be 33%.

Mucus production

0.47 (0.22)

19 (100)

After 12 weeks of using the new HMEs, 53% of patients will have decreased
mucus production compared with no HME use.

Speech quality

1.25 (0.23)

18 (95)Using the new HMEs for 12 weeks will result in 25% of patients having betterspeech quality compared with using the second-generation HMEs.

Physiotherapy

0.74 (0.70)

18 (95)The average number of days requiring chest physiotherapy will decrease by
0.74 days after 12 weeks of using the new HMEs compared with using thesecond-generation HMEs.

Tracheobronchitis or pneumonia episodes

0.66 (0.32)

18 (95)The percentage of decrease in pulmonary infections per year in patients using
the new HMEs compared with those using the second-generation HMEs willbe 34%.

Social contacts

1.13 (0.18)

18 (95)The percentage of increase in the average number of social contacts in patientsusing the new HMEs compared with those using the second-generation HMEs
after 12 weeks will be 13%.

QoLc

1.33 (0.30)

18 (95)The percentage of increase in the overall QoL in patients using the new HMEs
compared with those using the second-generation HMEs after 12 weeks willbe 33%.

Patient satisfaction

1.44 (0.30)

18 (95)Using the new HMEs will result in 44% of patients being more satisfied about
their HME when compared with patients using the second-generation HMEs
after 12 weeks.

Breathing

1.53 (0.28)

19 (100)

The use of the new HMEs will result in 53% of patients breathing better after
12 weeks of use.

Shortness of breath

1.48 (0.25)

19 (100)

After 12 weeks of using the new HMEs, 48% of patients will experience a
decrease in shortness of breath.

Tracheal climate

1.59 (0.19)

19 (100)

After 12 weeks of using the new HMEs, 59% of patients will experience a
decrease in tracheal dryness or irritation.

Coughing

2.95 (1.61)

19 (100)

The average amount of daily coughs per patient after 12 weeks of using the
new HMEs will be 2.95.

Forced expectorations

2.46 (1.42)

19 (100)

The average number of daily forced expectorations per patient after 12 weeks
of using the new HMEs will be 2.46.

Sleep quality

0.48 (0.22)

18 (95)After 12 weeks of using the new HMEs, 48% of patients will experience
sleeping problems.

Psychosocial aspects

0.24 (0.20)

18 (95)After 12 weeks of using the new HMEs, 24% of patients will experience psychosocial problems.

SEE: structured expert elicitation.

b

HMEs: heat and moisture exchangers.

c

QoL: quality of life.

Discussion
Principal Findings
The rapid review identified the benefits of the current HMEs
regarding breathing effort, tracheal dryness and irritation, mucus
production and plugging, inflammation and infection rates, sleep
quality, QoL, and patient satisfaction, which were confirmed
for the new HMEs by the experts during the interviews andSEE. There were some discrepancies regarding cough, forced
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expectorations, and psychosocial aspects: in the interviews, theexperts mentioned that the new HMEs will improve these
aspects, but this was not observed in SEE. In addition, theinterviewed experts did not expect to see an effect of using the
new HMEs on speech quality and the requirement ofphysiotherapy, but the SEE showed a positive effect for thesevariables. According to the interviewed experts, the new HME
portfolio will presumably lead to higher adherence to HME use
by patients and fewer health complaints and complications

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Ahmed et al

because of the improved HME properties, resulting in lower
health care use (eg, reduced hospital readmissions).

generation of HMEs, information can be generated to support
decision-making [46].

Comparison With Prior WorkA limitation to consider is the number of experts interviewed.
Even though the sample size was small, consensus on the viewson the new generation of HMEs was observed wheninterviewing the experts independently from each other. A
second limitation is that most experts who completed the SEE
survey did not yet have experience with prescribing the new
HMEs. Hence, the current effect estimations are likely to be anunderestimation of the true effect, as experts most likely filledin the survey conservatively. This point is addressed by our
results; it is noticeable that the experts responded moreconservatively when there was no comparison in the question
than when a comparison was included. The categories tracheal
dryness or irritation, mucus plug events, mucus production,
speech quality, physiotherapy, pulmonary infections, social
contacts, QoL, and patient satisfaction did contain a comparison,
all showing results in favor of the new HMEs. The questions
regarding the categories of breathing, shortness of breath, daily
coughs, daily forced expectorations, sleeping problems, andpsychosocial problems did not contain a comparator, and theresults mostly showed a less favorable expected effect for the
new HMEs, except for sleeping and psychosocial problems.
Because the standard of care of all the experts wassecond-generation Provox HMEs, it might be possible that theexperts subconsciously used these HMEs as comparators intheir mind when answering the questions without comparators.
In addition, some questions in the SEE survey contained
categories in which experts could choose X or greater than X(ie, ≥X). When the experts entered weights in this category, we
did not know exactly how much the expert meant by X or greaterthan X. We interpreted this by giving this category the value X
plus 1 interval so that it would have a greater impact on thecalculated mean. This could be an underestimation of the value
given by the experts. As this category was barely used by theexperts, it should not be regarded as a major limitation of thestudy.

The finding that HME use reduces coughing and forced
expectorations in patients who underwent laryngectomy iscomparable with the findings from previous studies [7,17], andthe finding that patients who use an HME experience bettersleep has also been reported before [13]. In line with our study,
2 studies reported improvements in coughing, the mean dailyfrequency of sputum production, forced expectoration, shortnessof breath, sleep problems, and perceived voice quality [15,24].
In comparison with an earlier study [42], the SEE demonstrated
that fewer patients (than reported) are expected to experiencea decrease in tracheal dryness or irritation when using the new
HMEs compared with when using the second-generation HMEs.
However, when we directly asked the experts if they expected
an increase or decrease in patients experiencing tracheal dryness
or irritation with the new HMEs compared with thesecond-generation HMEs, they reported a decrease on average.
In addition, compared with patients using the second-generation
HMEs, the experts expected a reduction in patients experiencing
mucus plug events in the postoperative period. In comparison,
another study reported that approximately one-tenth of thepatients using a second-generation HME developed mucus plugs
during the postoperative period [43]. After 12 weeks of using
the new HMEs, approximately half of the patients were expected
to experience decreased mucus production compared with noHME use. This is more than what was reported for the
first-generation HMEs [31] and less than what was reported forthe second-generation HMEs [41]. Besides, on average, thebreathing results expected with the use of the new HMEs wereless improved than those reported with the use of thefirst-generation HMEs [40]. Experts expected that more patients
will experience a decrease in shortness of breath with the useof the new HMEs compared with results obtained from the useof the first- and second-generation HMEs [31]. The experts also
expected that the average number of daily coughs after 12 weeks
of using the new HMEs will be slightly higher than that reported
after using the second-generation HMEs [42]. The same applies
to the average number of daily forced expectorations per patient[42]. The percentage of patients experiencing sleeping problems
after 12 weeks of using the new HMEs is expected to be notably
lower than that after using the first-generation HMEs [28]. The
number of patients who are expected to experience psychosocial
problems after using the new HMEs is similar to number ofpatients reported to experience psychosocial problems afterusing the first- and second-generation HMEs [31].

Strengths and Limitations
To the best of our knowledge, this study is the first to investigate
the expected effects of the new HMEs. A strength of this study
is the use of a mixed methods approach, which helped to gaina deeper understanding of the effectiveness of HMEs than would
be possible with the use of either approach alone. A second
strength is the overall consensus among clinicians from leading
German institutions on the benefits of the new HMEs comparedwith the current HMEs. Moreover, by using the literature andexpert beliefs at an early stage in the life cycle of the newhttps://formative.jmir.org/2023/1/e36401

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Future Considerations
It is recommended that the SEE survey be conducted once more
after the experts have gained experience with the new HMEs,
as the current effect estimations might be underestimated. To
generate primary data on the actual use of the new HMEs bypatients, it is recommended that a clinical study be set up toevaluate the effectiveness of the new HMEs. Both theperspectives of patients and health care providers need to be
included in future studies on HMEs to gain a complete pictureof the value of the new HMEs. Next, as in the current
reimbursement landscape, a new medical device needs to be
not only effective in improving patient outcomes but also
cost-effective, and conducting an economic analysis is
recommended.

Conclusions
According to German experts, the use of the new HMEs withimproved humidification levels by patients who underwent
laryngectomy is expected to have additional (clinical)
effectiveness on pulmonary health and QoL aspects comparedwith the currently available HMEs.
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Acknowledgments
The authors express their gratitude to all the experts who participated in the interviews and survey.
Panaxea received funding from Atos Medical to conduct this study. The funding party had no role in the study design; collection,
analysis, and interpretation of data; or writing of the manuscript. The funding party supported with the identification of experts
for the interviews. The views expressed in this manuscript are those of the authors and not necessarily those of Atos Medical.

Authors' Contributions
AA contributed to the development of the methods design (rapid literature review and expert interviews) and search strategy
design, data collection, data analysis, interpretation of data, and design and writing of the manuscript and was involved in the
final approval of the manuscript. JCM contributed to the development of the methods design (rapid literature review and expert
interviews) and search strategy design, data collection, and interpretation of data; regularly reviewed the work; provided feedbackon the manuscript; and was involved in the final approval of the manuscript. IWAB contributed to the development of the methods
design (structured expert elicitation [SEE]), to data collection (SEE), to data analysis, to the interpretation of data, to the writingof the manuscript and was involved in the final approval of the manuscript. HJMV conceptualized and designed the overall study;
contributed to the development of the methods design (SEE) and to the interpretation of data; regularly reviewed the work;
provided feedback on the manuscript; and was involved in the final approval of the manuscript.

Conflicts of Interest
None declared.

Multimedia Appendix 1
Topic guide for the interviews.
[PDF File (Adobe PDF File), 88 KB-Multimedia Appendix 1]

Multimedia Appendix 2
Average scores of expert judgements on effect variables.
[PDF File (Adobe PDF File), 123 KB-Multimedia Appendix 2]

Multimedia Appendix 3
Survey structured expert elicitation (SEE).
[PDF File (Adobe PDF File), 324 KB-Multimedia Appendix 3]

Multimedia Appendix 4
Average scores of expert judgements on effect variables.
[PDF File (Adobe PDF File), 419 KB-Multimedia Appendix 4]

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Abbreviations
EH: external humidifier
HME: heat and moisture exchanger
HRQoL: health-related quality of life
QoL: quality of life
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Ahmed et al

RLR: rapid literature review
SEE: structured expert elicitation
TL: total laryngectomy

Edited by A Mavragani; submitted 13.01.22; peer-reviewed by K Turner, ER Khalilian; comments to author 07.09.22; revised version
received 07.11.22; accepted 08.11.22; published 11.01.23
Please cite as:
Ahmed A, Mewes JC, Boot IWA, Vrijhoef HJM
New Heat and Moisture Exchangers for Laryngectomized Patients in Germany: Mixed Methods Study on the Expected Effectiveness
JMIR Form Res 2023;7:e36401
URL: https://formative.jmir.org/2023/1/e36401
doi: 10.2196/36401
PMID:©Anam Ahmed, Janne C Mewes, Iris W A Boot, Hubertus J M Vrijhoef. Originally published in JMIR Formative Research(https://formative.jmir.org), 11.01.2023. This is an open-access article distributed under the terms of the Creative Commons
Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work, first published in JMIR Formative Research, is properly cited. The complete
bibliographic information, a link to the original publication on https://formative.jmir.org, as well as this copyright and license
information must be included.

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