The Clinical Impact of POCUS Use: A Hybrid Type 2 Effectiveness-implementation Trial From Danish General Practice
Conditions: Point-of-care Ultrasound
Sponsor: Aalborg University

 
 
 
 
  
 
Study protocol 
The clinical impact of POCUS use: 
A hybrid type 2 effectiveness-implementation trial from 
Danish general practice 
Center for General Practice at Aalborg University 
19-02-2025 
 

The clinical impact of POCUS use in general practice  
1
Study protocol according to the SPIRIT 2013 Checklist 
Administrative information ............................................................................................................. 3 
1 
Title ...................................................................................................................................... 3 
2a 
Trial registration ............................................................................................................... 3 
2b 
 The World Health Organization Trial Registration Data Set .......................................... 3 
3 
Protocol version ................................................................................................................... 4 
4 
Funding ................................................................................................................................ 4 
5 
Roles and responsibilities .................................................................................................... 4 
Introduction ..................................................................................................................................... 6 
6 
Background and rationale .................................................................................................... 6 
7 
Specific objectives ............................................................................................................... 6 
8 
Trial design .......................................................................................................................... 8 
Methods - Participants, interventions, and outcomes ..................................................................... 8 
9  Study settings ....................................................................................................................... 8 
10 
Participants ....................................................................................................................... 9 
11a 
Description of the intervention ....................................................................................... 10 
11b 
Criteria for discontinuing or modifying allocated interventions .................................... 20 
11c 
Strategies to improve adherence to intervention protocols ............................................ 20 
11d 
Relevant concomitant care and interventions that are permitted or prohibited .............. 20 
12 
Outcome measures ......................................................................................................... 20 
13 
Time schedule ................................................................................................................ 23 
14 
Sample size ..................................................................................................................... 23 
15 
Recruitment .................................................................................................................... 23 
16a  Allocation Sequence generation ..................................................................................... 24 
16b 
Allocation concealment mechanism ............................................................................... 24 
16c 
Implementation............................................................................................................... 24 
17 
Blinding .......................................................................................................................... 25 
Data collection, management, and analysis .................................................................................. 25 
18a 
Data collection - Plans for assessment and collection of outcome ................................ 25 
18b 
Data collection - Plans to promote participant retention and complete follow-up......... 27 
19 
Data management ........................................................................................................... 27 
20a 
Statistical methods for analysing primary and secondary outcomes.............................. 27 
20c 
Missing data ................................................................................................................... 28 
Data monitoring ............................................................................................................................ 28 

The clinical impact of POCUS use in general practice  
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21a 
Data monitoring committee (DMC). .............................................................................. 28 
21b 
Description of any interim analyses ............................................................................... 28 
22 
Harms ............................................................................................................................. 28 
23 
Auditing .......................................................................................................................... 28 
Ethics and dissemination............................................................................................................... 28 
24 
Research ethics approval ................................................................................................ 28 
25 
Protocol amendments ..................................................................................................... 29 
26a 
Consent or assent ............................................................................................................ 29 
26b 
Additional consent provisions for collection and use of participant data ...................... 29 
27 
Confidentiality ................................................................................................................ 29 
28 
Declaration of interests................................................................................................... 29 
29 
Access to data ................................................................................................................. 29 
30 
Ancillary and post-trial care ........................................................................................... 29 
31a 
Dissemination policy ...................................................................................................... 29 
31b 
Authorship eligibility guidelines .................................................................................... 30 
31c 
Plans for granting public access ..................................................................................... 30 
32 
Informed consent materials ............................................................................................ 30 
References ..................................................................................................................................... 30 
 
 
 

The clinical impact of POCUS use in general practice  
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Administrative information 
 
1 
Title 
The clinical impact of POCUS use: A hybrid type 2 effectiveness-implementation trial from 
Danish general practice 
 
2a 
Trial registration 
The trial will be registered on clinicaltrials.org 
 
2b 
 The World Health Organization Trial Registration Data Set 
 
Data category 
Information 
Primary registry and trial 
identifying number 
Clinicaltrials.gov number: NCT05523882 
Date of registration in 
primary registry 
Uploaded to clinical trials on August 29 2022 
Secondary identifying 
numbers 
Red-CAP registration number Record ID 242-3  
Source(s) of monetary or 
material support 
n/a 
Primary sponsor 
Center for General Practice at Aalborg University (CAM AAU) 
Secondary sponsor(s) 
Novo Nordisk Foundation 
The General Practice Foundation in Denmark 
Contact for public queries 
mbj@dcm.aau.dk 
Contact for scientific queries 
caakjaer@dcm.aau.dk 
Public title 
The clinical impact of POCUS use in General Practice  
In Danish: Den kliniske betydning af brugen af ultralyd – et forskningsprojekt fra 
dansk almen praksis 
Scientific title 
The clinical impact of POCUS use: A hybrid type 2 effectiveness-implementation 
trial from Danish general practice 
Countries of recruitment 
Denmark 
Health condition(s) or 
problem(s) studied 
The use of point-of-care ultrasonography (POCUS) in general practice 
Intervention(s) 
An educational intervention consisting of three teaching seminars over three 
months, a curriculum of 10 point-of-care ultrasound (POCUS) applications, an 
online learning platform providing educational support before, during and after 
the teaching sessions. 
Key inclusion and exclusion 
criteria 
Inclusion criteria:  
1. postgraduate medical doctor with a specialization in general practice. 
2. work in office-based general practice in Denmark 
3. access to an ultrasound device in the practice during the study period  
Exclusion criteria:  
1. possible conflict of interest  
2. no signed informed consent to participate. 
Study type 
A hybrid type 2 effectiveness-implementation trial 
Date of first enrolment 
Expected: August 2022 
Target sample size 
Twenty general practitioners  
Recruitment status 
Not yet recruiting 
Primary outcome(s) 
This study aims to simultaneous assess the clinical effectiveness of the 
intervention and to measure the impact of the implementation strategy as co-
primary aims.  
 

The clinical impact of POCUS use in general practice  
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3 
Protocol version 
Version 8 August 28th 2022 
 
4 
Funding  
This study will be conducted as independent research at Center for General Practice at Aalborg 
University and is financially supported by The Novo Nordisk Foundation (grant number 
0061821) and The General Practice Foundation in Denmark (grant number A3495). 
 
5 
Roles and responsibilities 
 
5a  
Names, affiliations, and roles of protocol contributors 
Camilla Aakjær Andersen (CAA) will be the principal investigator.  
CAA, Martin Bach Jensen (MBJ), Julie Jepsen Strøm (JJS) will oversee the choice of and 
collection of outcome measures 
CAA and MBJ wrote the first draft of the protocol.  
Allan Riis (AR) will draft the data handling and statistical analysis plan (SAP) 
Søren Lundbye-Christensen (SLC) will help draft the SAP.  
Thomas Løkkegaard (TL) and Christian Stjernebjerg (CS) will participate as course directors in 
the educational intervention.  
CAA, MBJ, JJS, SLC, AR, TL, and CS are all expected to make valuable scientific additions to 
the draft and will be co-authors on subsequent manuscripts based on these data. The definition of 
author is defined on ICMJE´s four criteria1:  
 
Substantial contributions to the conception or design of the work; or the acquisition, analysis, or 
interpretation of data for the work; AND 
Drafting the work or revising it critically for important intellectual content; AND 
Final approval of the version to be published; AND 
Agreement to be accountable for all aspects of the work in ensuring that questions related to the 
accuracy or integrity of any part of the work are appropriately investigated and resolved. 
   
The expected author list is: Andersen CA, ……Jensen MB. 
 
5b 
Name and contact information for the trial sponsor 
Trial sponsor: Center for General Practice at Aalborg University (CAM AAU) 
Contact name: Camilla Aakjær Andersen 
Address: Center for General Practice in Aalborg, Fyrkildevej 7, 1., 9220 Aalborg East, Denmark  
E-mail: caakjaer@dcm.aau.dk 
 
5c 
Role of study sponsor and funders 
Sponsor (CAM AAU) is part of the study design, data analyses and writing of the manuscript. 
Sponsor will ensure that the results will be submitted for publication. Sponsor is non-commercial 
and declares no conflict of interest. 
 
Other sponsors have no part in the study design, data analyses or writing of the manuscript. 
 

The clinical impact of POCUS use in general practice  
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The authors declare no conflict of interest. 
 
5d 
Composition, roles, and responsibilities of the steering committee and safety 
committee (see Item 21a for data monitoring committee) 
 
A steering committee affiliated with CAM AAU (TL, Ulrike Mehnert (UM), Troels Mengel-
Jørgensen (TMJ), Søren Kæseler Andersen (SKA), MBJ and CAA) will handle and oversee the 
development of the intervention, the coordination and organisation of the ultrasound courses, and 
the data collection and data management.  
 
A safety committee will be set up to handle all reports of adverse and suspected adverse events 
(AEs) and serious adverse events (SAEs). MBJ will head the committee.  
 
 
 

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Introduction 
6 
Background and rationale 
In 2023/2024 the POCUS IN PRACTICE (PIP) study, a large stepped wedged cluster 
randomized clinical trial (SW-CRT) will be conducted in general practice in Denmark. The 
overarching aim of this study is to evaluate the implementation of point-of-care ultrasound 
(POCUS) in Danish general practice. An educational intervention for this study has been 
developed and tested in a previous study (Evaluating scanning competence following a 
structured POCUS training program for general practitioners: A hybrid effectiveness-
implementation study: Clinical trials registration: NCT05274581). Since then, the intervention 
has been further developed and in line with the medical research council’s framework for 
developing and evaluating complex interventions2, the intervention is ready for the next stage of 
evaluation (figure 1). 
 
Figure 1. Flowchart of the study process  
 
 
OK 22: Projects included in the 2022 collective agreement between Danish Regions and The Danish Association of General Practitioners.  
OK 25: The 2025 collective agreement between Danish Regions and The Danish Association of General Practitioners, will possibly include a 
larger scale implementation of POCUS in general practice depending on the results of the OK22 projects.  
 
   
 
7 
Specific objectives  
Being a hybrid type 2 effectiveness-implementation study3, this study aims to simultaneous 
assess the clinical effectiveness of the intervention and to measure the impact of the 
implementation strategy as co-primary aims. The implementation-related outcomes have been 
developed based on recommendations for implementation strategy measures for use in feasibility 
and pilot implementation studies4. 
 
Outcomes to assess the effectiveness of the intervention:  
For GPs attending a 3-months basic POCUS course, we aim to determine:  
(E1) how the frequency of use of different POCUS examinations develops in the first two 
years after introducing POCUS use in general practice including the variation over time 
and between GPs. 

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(E2) how the frequency of referrals for secondary care develops in the first two years 
after introducing POCUS use in general practice and including the variation in referrals 
over time and between GPs. 
(E3) how the number of consultations delivered in primary care develops in the first two 
years after introducing POCUS use in general practice including the variation over time 
and between GPs. 
(E4) how the GPs’ reported effect of POCUS on their clinical decision and patient 
management in general practice develops in the first year after introducing POCUS use in 
general practice. 
(E5) the number of unwanted cases associated with the use of POCUS reported by the 
participating GPs in the first two years after introducing POCUS use in general practice.  
 
Outcomes to assess implementation strategy effects: 
(I1) Adoption: the proportion of participating GPs that adopt the intervention and start 
using POCUS in their daily practice during the educational interventions (months 1-3).   
(I2) Fidelity (adherence): the proportion of participating GPs that complete the 
educational elements in the intervention (pre-post tests, webinars, assignments, 
attendance on seminar days, logbook registrations). 
(I3) Reach (penetration): The proportion of teachers who actively support participants by 
engaging in the online part of the educational interventions  
(I4) Sustainability (maintenance): the proportion of participating GPs that adopt the 
intervention and continue to use POCUS in their daily practice following the educational 
interventions (months 5-6).   
 
Outcomes to inform further development of the implementation strategy 
(D1) Adaptability: the extent to which the teachers and participants find that the 
implementation of the educational intervention meets local needs  
(D2) Acceptability: the extent to which the teachers and participants find the 
implementation of the educational interventions is agreeable in terms of content and 
delivery  
(D3) Feasibility: the extent to which the teachers and participants find the educational 
intervention to be suitable for implementation  
(D4) Compatibility (appropriateness): the extent to which the teachers and participants 
perceive the implementation of the educational intervention is in line with the 
organisation’s values, mission, priorities  
(D5) Dose (satisfaction): the extent to which the teachers and participants are satisfied 
with the amount of support and resources received as part of implementation strategy 
(D6) Complexity: the extent to which the teachers and participants perceive the 
implementation of the educational intervention as being difficult or complex  
(D7) Context: the extent to which the teachers and participants find that organisational 
political, economic or social factors influenced the implementation of the educational 
intervention 
(D8) Culture: the extent to which the teachers and participants find that the setting, 
organisational values or norms influenced the implementation of the educational 
intervention   

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(D9) Self-efficacy: the extent to which the teachers and participants find that they had the 
capacity (e.g. knowledge and skills) to implement the educational intervention  
(D10) Cost: measures of the cost of implementation the educational intervention   
(D11) Resources: measures of the resources and managing required for the 
implementation the educational intervention   
 
Outcomes to assess the feasibility of trial methods 
(F1) the extent to which recruitment of participants was possible  
(F2) the extent to which participants retention was possible  
(F3) the extent to which retention of teachers was possible 
(F4) the extent to which teachers delivered the intervention by protocol  
(F5) the extent to which participants received the intervention by protocol  
(F6) the extent to which data collection through registers was obtainable and valid 
(F7) the extent to which data collection through GP questionnaires was obtainable and 
valid 
(F8) the extent to which data collection through GP questionnaires was obtainable in a 
questionnaire measuring GPs’ sense of burnout, stress and job satisfaction estimated 3 
months after introducing POCUS in general practice.   
 
8 
Trial design  
We use the effectiveness-implementation hybrid trial design typology proposed by Curran et al3 
which has been found suitable for preparatory studies in relation to implementing complex 
interventions4. This is a hybrid type 2 effectiveness-implementation trial3, with simultaneous 
testing of both the effectiveness of an intervention and the feasibility of the implementation 
strategy as co-primary aims. This hybrid type is a blending of clinical effectiveness and 
implementation research that aims in support of more rapid translation. As the implementation 
strategy is being tested alongside and in support of a clinical intervention, it is possible to create 
and study a “medium case”/pragmatic set of delivery/implementation conditions versus “best” or 
“worst” case conditions. Therefore, while speeding translation, it is possible with Hybrid Type 2 
designs to provide more valid estimates of potential clinical effectiveness3. 
 
We previously tested other effectiveness related outcomes (the educational intervention’s ability 
to give participating GPs’ scanning competence) in a hybrid type 1 effectiveness-implementation 
trial5 and the present study builds on the evaluation of implementation-related outcomes from the 
previous study.   
 
Reporting of this trial will follow the guidelines for reporting implementation studies: The StaRI 
standard6. Reporting of the protocol will follow the SPIRIT statement7. Before data collection 
starts, the trial will be registered on clinicaltrials.gov.  
Methods  
 
9  
Study settings  
This study will be conducted in office-based general practice in Denmark with the educational 
sessions taking place at two different ultrasound educational facilities.  

The clinical impact of POCUS use in general practice  
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GPs in Denmark are self-employed and work in office-based general practice clinics. Denmark 
has a public health care system where almost all patients are listed with a GP for primary health 
care. Consultations and treatments are free-of-charge for patients. GPs act as gatekeepers for 
other primary care healthcare providers and secondary care specialists. GPs are paid through a 
combination of remuneration and fee-for-service financed through taxes. There is no fee for 
performing POCUS in primary care and GPs must cover expenses for the ultrasound device and 
their ultrasound education themselves.  
 
Continuous medical education for GPs is centrally organized under the wings of the Organisation 
of General Practitioners in Denmark (Praktiserende Lægers Organisation PLO) that has an 
educational branch (PLO-e). PLO-e is the practical organizer of the ultrasound course delivered 
in this educational intervention. PLO-e had no influence on the scientific content or data 
collection in the study.       
 
The study will be coordinated from CAM AAU and data will be collected by the research team 
at the training sessions and by the participating general practitioners in their clinics. All study 
data will be stored at a secure server at Aalborg University. 
 
Some of the GPs participating in this study may later on be eligible to have the course fee 
reimbursed and receive payment for the scans (approximately DKR 262 per scan).  A decision 
regarding this lies not with the research team, but will depend on matters relating to the general 
practice agreement between PLO and the Danish Regions. A decision regarding this is expected 
in September 2022. 
 
 10 
Participants   
All GPs participating in two ultrasound courses organized by PLO-e (course number 9018822 
and 9017222) are eligible to participate in this study. Independent of previous use of ultrasound 
in general practice, participants had to meet the following criteria:  
  
Inclusion criteria:  
1. Postgraduate medical doctor with a specialization in general practice 
2. Working in office-based Danish general practice   
3. Access to an ultrasound device in the practice during the study period 
Exclusion criteria:  
1. Not willing to participate in the data collection or share data for this study 
2. No signed informed consent to participate 
 
All patients seen in general practice, that the GPs find relevant to examine with POCUS can be 
used in the data collection. For this study, we will not collect identifiable personal or health-
related data on patients. However, we will receive aggregated data on patients’ age and gender. 
These data are used to describe the patient population but will neither be stored with the other 
study data nor used in analysis with other data (see section 12). 
 
 
 

The clinical impact of POCUS use in general practice  
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11a 
Description of the intervention  
All participants will receive the educational intervention through attendance of the ultrasound 
course arranged by PLO-e. The educations intervention consists of three teaching seminars 
delivered over three months, a curriculum of 10 POCUS applications, an online learning 
platform providing educational support before, during, and after the teaching sessions (see Figure 
2).  
The online platform includes videos demonstrating the performance of POCUS, suggestions for 
additional literature, assignments to support the development of skills, self-quizzes to focus 
attention of learning outcomes and specific actioncards for each of the 10 POCUS applications 
framing the examinations in the clinical context. In addition, the online platform provides 
participants access to webinars and communication with other participants and teachers.       
 
Figure 2 Point-of-care ultrasonography educational intervention for general practitioners  
 
 
 
Individual preparation (Days 1-7)  
Prior to the first seminar day, the participants are invited to access and complete the preparatory 
material on the digital platform (Microsoft Teams), which includes suggested literature and 
videos about the basics of ultrasonography, how to perform POCUS, how to use POCUS in the 
examination of patients, and how to integrate POCUS in the general practice consultation. To 

The clinical impact of POCUS use in general practice  
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prime the participant prior to the first seminar the preparation includes a pre-self-quiz outlining 
the specific learning outcomes of the first seminar day.    
The participants also have to send in a motivational description where they in words will declare 
their motivation for participating in the course, their expectations for the course, their individual 
learning goals, their previous experiences with POCUS and other prerequisites. They will also be 
asked to identify possible barriers towards their learning process and pose three questions that 
they want answered during the first teaching seminar. This allows for the participants to reflect 
on their own motivation and capability and any difficulties and questions they may have. The 
participants are encouraged to enter the first training session with a focus on their individual 
learning goals and to make sure that difficulties and questions are addressed during the seminar. 
The POCUS teachers will comment on the participants’ assignments. The assignment and 
comments will be saved in the online platform.  
The teachers will address and integrate topics from the assignments during the first teaching 
seminar.   
The pre-course assignment will also include a baseline questionnaire for participants, where they 
will be asked to declare their background information.  
  
The participants must require an ultrasound device prior to the first teaching seminar and become 
familiar with basic functions. The participants are asked to register questions and difficulties 
related to the use of their ultrasound device either in the motivational description or by hand in 
order to bring these to the first teaching seminar.    
 
Introductory webinar  
Early in the preparation phase, the participants will be invited to attend an introduction webinar, 
where the course leader will introduce the online platform and the course contend to the 
participants. The purpose of the introduction webinar is to stimulate commitment, create 
awareness about course content and requirements, and introduce and facilitate use of the online 
platform. The participants will also be encouraged to plan for the implementation of POCUS 
training during daily routines, to allocate time for practice each week, and to discuss possible 
barriers for this with colleagues.    
 
Curriculum 
From a previous qualitative study, we know that GPs select and perform POCUS examinations 
that are focused on a specific clinical problem, relevant in the clinical context, within the GPs 
area of interest, not too time consuming, and not too difficult to perform8. For this education 
intervention 10 POCUS scanning modalities have been selected. 
This selection is based on: (1) a previous systematic needs assessment9 assessing the relevance of 
different scanning modalities, (2) previous studies measuring the frequency of different POCUS 
modalities used in general practice8 10, (3) a national survey in Denmark exploring which 
POCUS examinations were performed by GP9, and (4) evidence of the diagnostic accuracy of 
different scanning modalities performed in the hands of non-imaging specialists (Table 1).  
Hence, the selected curriculum for this study include ten POCUS scanning modalities that are 
frequently encountered in general practice, relevant in the clinical setting in terms of POCUS 
examinations with an impact on diagnostic security or clinical pathway and manageable in terms 
of performance and competence.     

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To prevent cognitive overload10 11 and because previous studies have shown that GPs often start 
scanning just a few applications7 19, the ten scanning modalities in the curriculum will be 
introduced stepwise. Five scanning modalities will be introduced on the first teaching seminar, 
while the remaining five applications will be introduced on the second teaching seminar.   
 
 
 
Table 1 Diagnostic accuracy of curriculum for the educational intervention  
Curriculum 
Diagnostic accuracy* 
% of current 
users who 
perform the 
examination 
(National survey)20 
% of users who 
found the 
examination 
relevant  
(Delphi study)9 
 
sensitivity specificity 
First teaching seminar  
 
 
 
 
 
Residual urine (bladder)12 
69.0 
99.0 
72% 
100% 
 
Hydronephrosis (kidney)13 
70.2  
75.4 
46% 
95% 
 
Viable intrauterine pregnancy (uterus)14 
97.0 
98.0 
87% 
93% 
 
Joint effusion (knee)15 
0.84 
0.93 
46% 
73% 
 
Gallstone (Gall bladder)16 
89.8 
88.0 
64% 
98% 
Second teaching seminar  
 
 
 
 
 
Ascites (abdominal FAST)17 
100.0 
100.0 
37% 
85% 
 
Intrauterine device location (uterus)** 
 
 
86% 
95% 
 
Constipation (Rectum diameter)*** 18 
95.5 
94.1 
19% 
46% 
 
Subcutaneous abscess (skin)19 
96.2 
82.9 
42% 
98% 
 
Pleural effusion (lung)20 
88.0 
90.0 
28% 
76% 
*Diagnostic accuracy of POCUS reported in studies using the same scanning protocol as we intend to use in this intervention.  
** No studies have been identified, where ultrasound is compared to a gold standard e.g. MRI or CT scan  
*** Using POCUS for measuring rectal diameters as part of the ROM-IV criteria for diagnosing constipation in children is a relative new 
scanning modality and as such the GPs participating in the above-mentioned studies, have not been trained to perform the examination. However, 
the examination has been included in the NICE guidelines and the patient category is common in general practice.  
 
Actioncards 
A basis of the educational intervention are actioncards designed for each POCUS scanning 
modality (figure 3). The actioncards are 1-page instructions specifying the indication for 
performing the POCUS examinations, the transducer and specific equipment settings needed to 
perform the examination, the POCUS procedure including transducer placement, image 
acquisition and optimization, the interpretation of the examination, possible pitfalls to be aware 
off and integration of findings into a clinical context21.  
The actioncards are used as résumés of the preparation literature, to structure the examination 
during the teaching seminars and as supporting guidelines that can be used or consulted during 
the examination if needed.      
 
Instruction videos  
An instruction video is developed for each scanning modality included in the curriculum. All 
instruction videos are built with a structure similar to the structure of the actioncards: (1) 
Description of the indication for the examination, (2) Description of the needed equipment and 
equipment settings, and (3) demonstration of the conduction of the POCUS examination 

The clinical impact of POCUS use in general practice  
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including tips and tricks regarding transducer placement, patient cooperation, image optimization 
etc.  
The video demonstration of the performance of the POCUS scan will be divided into three 
pictures that are displayed simultaneously. One picture illustrating the ultrasound image on the 
monitor, one picture illustrating the hand on the transducer and thereby the transducer 
manipulation and one picture illustrating the anatomy.  
 
 
Figure 3 Actioncards describing a specific scanning modality 
 
 
Self-tests 
Participants have access to self-tests before (pre-self-test) and after (post-self-test) each teaching 
seminar. These self-tests include 10-15 questions covering the learning outcomes of each 
teaching seminar and the pre- and post-tests for each seminar are largely similar. Some questions 
will concern ultrasound physics and basic scanning knowledge, others will be more application 
specific. Hence, the pre-self-test is designed to prime participants and create awareness about the 
learning outcomes of the following teaching seminar, whereas the post-self-test is designed as 
individual feed-back for participants and to create awareness about certain difficulties or missed 
information. The POCUS-teachers will monitor the results of these tests as part of their 
assessment of the participants learning progress.    
 
Assignments  
Throughout the learning process, participants will be invited to complete online assignments. 
The first assignment (Motivational description 1) will be a questionnaire concerning the 
Indication for 
using POCUS 
Equipment 
needed 
Procedure 
description 
and image 
illustration 
Possible 
pitfalls  
Interpretation in 
a clinical context  

The clinical impact of POCUS use in general practice  
14 
individual participants’ capability, opportunity and motivation for using POCUS. These factors 
are known key-elements driving the behavior of healthcare providers22. Hence, we aim to 
identify previous experience with POCUS in order to assemble groups of participants with 
similar background for the hands-on sessions, identify possible barriers for the learning process 
in order to remove these or minimize the influence of these in the learning process and identify 
motivational factors to create awareness about these among participants and to use these in the 
learning process and mentoring.  
In between teaching seminars, a number of assignments will include uploading of POCUS scans 
for review and feed-back from the POCUS teachers. Before the second and third seminar day, an 
assignment will be sent to participants (Motivational description 2 and 3) including a 
questionnaire where participants are asked to specify learning goals and questions for the coming 
teaching seminar in order to create awareness about these. Participants are encouraged to brings 
these to the teaching seminar to ensure that questions are covered or addressed during the 
seminar.   
 
Webinars  
In between teaching seminars, participants will be invited to participate in short webinars 
addressing obstacles and difficulties encountered in the learning process. The course director and 
the teachers will have gathered topics for the webinar from monitoring the individual 
participants’ learning processes registered in logbooks, self-tests results, uploaded assignments 
or questions posed in the chat forum. Webinars will be approximately 30 minutes and 
participants will have the opportunity to ask questions during the sessions.       
 
Online groupware platform (from day 1) 
The educational intervention includes an online groupware platform (figure 4), which all 
participants in the course and the teachers have access to.  
 
Figure 4 Online platform to support the longitudinal learning process  
 
 
 
Through the online platform participants will have access to:  

The clinical impact of POCUS use in general practice  
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1. Course information including timelines, course material, general and practical information.  
2. Folders where actioncards, documents, instruction videos and other education material are uploaded.  
3. A wall for sharing information between all participants. Here there is a group chat function, where 
participants may share experiences and reflections with each other the learning process. The teachers may 
also engage in this ongoing debate. Videos, documents, links etc. may be uploaded or posted and shared 
here and all participants will have the opportunity to comment on uploads and posts. Notifications for the 
participants are also posted here.  
4. Invitations to webinars with the teachers, where tips and tricks are shared based on the participants 
uploaded or returned comments, feed-back, uploads and logbook registrations. 
5. A document where notes can be shared between the participants during webinars or teaching seminars. 
6. Link to the individual assignments to be completed by participants during the learning process. The 
teachers on the course have the opportunity to comment and respond in the assignment.  
7. A link to an online logbook where the individual participant can note conducted POCUS examination 
during the learning process (date, type of POCUS, focus during the examination, reflections afterwards). A 
template specifies the number of examinations recommended at each phase in the educational intervention.  
8. A direct chat opportunity with the teachers, where participants can have access to guidance and support 
from the course teachers. It is also possible to upload scanning images or videos for review by the teachers.  
9. The individual structured feedback for all scanning modalities collected at teaching seminar 2 and 3.   
10. Access to Pre/post self-quizzes before and after each training seminar and access to the results.  
 
Participants will receive a notification by email or on their phones, when there is activity on the 
online platform. The overall purpose of this online platform is to support the participant in the 
continuous learning process. We aim to create awareness about the learning process, individual 
focus points and goals, the importance of training and gaining experience, and to make guidance 
available when difficulties/problems are encountered.   
 
Teaching seminars (day 7, 37 and 97) 
The educational intervention includes three teaching seminars on days 7, 30 and 90. All seminar 
days have a similar overall structure with a focus on hands-on training and the individual 
participant’s development of scanning competences. However, the teaching aims are different on 
each seminar which means different focus in the teaching and different activities between 
seminar days.    
 
Teaching seminar 1 
The aim of the first teaching seminar is to give participants first-hand experiences with 
performing POCUS scans and to create a foundation of knowledge and experience which is to be 
further developed in the coming months. Furthermore, the participants will learn to perform five 
of the POCUS scans in the selected curriculum.  
The teaching seminar will start off with a short lecture summarizing the theoretical foundation 
for using POCUS and the participants preparation. The teachers will summarize the results of the 
motivational descriptions and address questions, barriers and concerns raised by participants. 
Afterwards, a short lecture will follow introducing basic transducer manipulation and image 
optimization. The participants are then introduced to the five selected POCUS modalities in a 
short lecture summarizing the fundamentals of the five scans. The participants are then divided 
into small groups of four participants based on their POCUS experience as declared in the prior 
assignment. Participants working in the same practice, will be separated into different group to 
ensure a good group dynamic. The small groups will now circulate between hands-on workshops 
(Figure 5). Each hands-on workshop will focus on one scanning modality. At the workshop, a 

The clinical impact of POCUS use in general practice  
16 
teacher demonstrates the scanning modality according to the specific actioncard. The 
participants then take turns explaining the performance of the scan and practice performing the 
POCUS examination on healthy volunteers (or phantoms for pelvic ultrasound).  The teacher will 
assist and provide guidance. During this first teaching seminar, the participants attend five 
workshops and thereby get their first experiences with conducting five of the POCUS 
examinations according to the actioncards. The participants attend the five workshops twice – 
first with a focus of getting the view and optimizing the view and second with a focus on 
optimizing the image. Hence, the workshops are constructed in order to (1) conceptualize the 
POCUS scan, (2) visualize the POCUS scan, (3) verbalize the POCUS scan and finally (4) 
practice the POCUS scan23. The overall aim with the workshops is to enable participants to 
perform the five POCUS examination with assistance.   
 
Figure 5. Structure of hands-on workshops on the first teaching seminar  
 
 
The participants will have the opportunity to bring their own ultrasound device for the teaching 
seminar in order to learn to master their own device. The small groups are composed to match 
members with similar equipment, prior knowledge and similar competence.   
At the beginning of the day, the participants will be asked to share their learning goals and 
specific challenges with their small group and at the end of the day, they will have time to 
discuss the learning outcomes of the day and consult the teachers with unanswered questions.    
After the teaching seminar a post-self-quiz is available (a replication of the pre-self-quiz) for the 
participants to create awareness about learning process and to illustrate to which extend the 
learning objectives of the first teaching seminar made been reached. The teachers will reach-out 
and offer extra support to participants where the test scores or performance during the hands-on 
workshops reveal problems or difficulties.    
 
In-between teaching seminar 1 and 2 (practice phase) 
After the first teaching seminar participant are encouraged to start practicing POCUS 
examinations. This phase in the learning process is considered and articulated as a training phase, 
where participants are to conduct as many POCUS examinations as possible with a primary aim 

The clinical impact of POCUS use in general practice  
17 
of training without having to draw conclusions based on their scans. As such, participants are in 
this phase encouraged to treat patients as usual without taking scan results into account. 
Participants are also encouraged to train examinations on volunteers e.g. family members, as the 
goal in this phase is to perform as many examinations as possible.  
During the three weeks between the two teaching seminars, participants are encouraged to 
register all POCUS examinations in their individual logbook and note reflections and questions 
that occur during this process.  It is recommended that participants aim to perform a minimum of 
three POCUS examinations of each scanning modality in the curriculum and upload one POCUS 
examination of each scanning modality for review by the teachers (assignments 2, 3, 4, 5, and 6).  
Midway in the practice phase (day 20), participants will be invited to participate in a half-an-
hour webinar. In this webinar, one of the teachers will go though some of the encountered 
problems and difficulties uploaded or posted on the online platform. Participants will also have 
the opportunity to ask questions.  
Prior to the second teaching seminar, motivational description 2 is send to the participants. In 
this assignment participants have to register their specific focus points and individual learning 
goals for the second seminar as well as any questions they may have to the teachers. 
A specific pre-self-quiz will be available before teaching seminar 2. This self-test will access 
basic knowledge of the five POCUS scans introduced at the first teaching seminar and prime the 
participants for the learning objective of the second teaching seminar.   
 
Teaching seminar 2 
From evaluation of previous POCUS training sessions, we know that GPs usually start off 
practicing their scanning skills by selecting a few scanning modalities in the curriculum. Thereby 
they develop a comfort zone of scanning modalities before they move on to include more 
scanning modalities in their portfolio. Therefore, the aim of the second training seminar is to (1) 
validate the scanning modalities that the participating GPs have been practicing in order to adjust 
and improve their performance, (2) to repeat and refresh the scanning modalities in the 
curriculum, that the participants have not been practicing in-between the teaching seminars to 
make the participant comfortable to move on to train these or even include these in their 
portfolio, (3) to provide feedback on performance and allow for guidance and support on 
encountered problems or difficulties and (4) to introduce five new POCUS modalities.  
The teaching seminar starts off with a plenum session where encountered experiences, problems 
or difficulties are shared and discussed. The teachers will address registrations and reflections 
from the logbooks, motivational descriptions and common difficulties identifies in the uploaded 
scans. The participants are invited to openly share and discuss. Afterwards, the participants are 
divided into small groups of four participants and they then circulate between hands-on 
workshop stations, as they did in teaching seminar 1. The first five workshop stations will 
include the five scanning modalities taught at the first teaching seminar. Here, the teacher will 
not demonstrate the scan or lecture, instead the participants will take turns demonstrating the 
scan for the teacher. The teacher will then assess the participants’ individual scanning 
competences using an adapted version of the OSAUS score including only items 2-5 which focus 
solely on the technical and practical ability to produce ultrasound images. It has been the 
intention from the beginning, that items 1 and 6 should only be used if applicable13. The teachers 
will give feedback on ways to improve performance and help the participants to set new learning 
goals and focus points for the continuous learning process. The feedback and teacher suggestions 
are uploaded to the participants individual channels on the online platform, allowing participants 

The clinical impact of POCUS use in general practice  
18 
to consult these at a later stage in the learning process. While one participant is demonstrating 
the scan for the teacher using one of the scanners at the workshop, the remaining three 
participants will practice performing the scan and give each other feedback using the other 
ultrasound device.      
Following the first five workshops, there will be a short lecture for all participants, where the 
five new scanning modalities are explained and elaborated. After this the participants return to 
the workshops.   
The next five workshop stations will introduce five new scanning modalities from the selected 
curriculum. At the workshop, a teacher will demonstrate the scanning modality according to the 
specific actioncard. The participants will then take turns explaining the performance of the scan 
and practice performing the POCUS examination on healthy volunteers (or phantoms for pelvic 
ultrasound).  The teacher will assist and provide guidance.  
 
After the second teaching seminar a post-self-quiz is available (a replication of the pre-self-quiz 
for teaching seminar 2) for the participants to create awareness about learning process and to 
illustrate to which extend the learning objectives of the first teaching seminar made been 
reached. The teachers will reach-out to participants, where the test scores reveal problems or 
difficulties, as well as participants, where the OSAUS score revealed specific difficulties. These 
participants will be offered additional support if needed.   
 
In-between teaching seminar 2 and 3 (developing phase) 
This phase in the learning process is considered and articulated as a developing phase, where 
participants continue to develop their scanning skills and routines. The participants are 
encouraged to use POCUS examinations on all patients with relevant clinical conditions suited 
for POCUS and to work with the integration of POCUS into their clinical practice and medical 
decision making. It is important in this phase that the participants develop routines and become 
comfortable performing POCUS examinations.  During the eight weeks between the teaching 
seminars 2 and 3, participants are encouraged to register all POCUS examinations in their 
individual logbooks and note reflections and questions that occur during this process. The 
participants will still have the opportunity to consult the teachers during this phase by uploading 
questions, images or videos to the online platform. It is again recommended that participants 
perform a minimum of three POCUS examinations on patients within each scanning modalities 
during the eight weeks and that participants upload at least one POCUS examination of each of 
the five new scanning modalities for review and feed-back (assignments 8-12).    
During the eight weeks, participants will be invited to participate in two half-an-hour webinars 
(on day 50 and 75). At these webinars, one of the teachers will go though some of the 
encountered problems and difficulties uploaded or posted on the online platform and present 
images and videos of common pathologies with the 10 selected POCUS modalities. Participants 
will also have the opportunity to ask questions and the teacher will have an ultrasound device 
and a volunteer available for live POCUS demonstration.  
Before the third and final teaching seminar, the participants will be asked to complete a pre-self-
quiz and to send in a list of questions or topics that they want included in the final teaching 
seminar (assignment 13).  
 

The clinical impact of POCUS use in general practice  
19 
Teaching seminar 3 
Before the final teaching seminar, the teachers will prepare feedback for each participant based 
on the information gathered about each participant, i.e., from notes in the logbook, the uploaded 
scans, impressions from teaching seminars, the correspondence in the chat function, etc. 
The structure of this final teaching seminar is similar to previous seminars. However, besides 
validating, adjusting and improving the participants’ POCUS examinations, the goal is also to 
evaluate the participants’ learning process, scanning competence and to offer guidance for future 
development.  
Like the second seminar, this teaching seminar starts off with a plenum session where 
encountered experiences, problems or difficulties are shared and discussed. The teachers will 
address questions raised on the online platform and common difficulties identifies in the 
uploaded scans. The participants are invited to openly share and discuss. Afterwards, the 
participants are divided into small groups of 4 participants and they then circulate between 
hands-on workshop stations, as they did on the previous seminars. At the workshop stations, the 
participants will take turns demonstrating the POCUS scan for the teacher (figure 6). The teacher 
will then assess the participants’ individual scanning competences using item 2-5 on the OSAUS 
score, give feedback on ways to improve performance and help the participants to set new 
learning goals and focus points for the continuous learning process. The participants will also 
receive suggestions for improvement from fellow participants, as the instructor invites to a 
discussion about the use of the scanning modality in general practice. The feedbacks and teacher 
suggestions are uploaded to the online platform, so participants may consult these at a later stage.   
 
Figure 6. Structure of hands-on workshops on the third teaching seminar  
 
 
At the end of the teaching seminar, participants will be asked to evaluate the educational 
intervention in a questionnaire and in a final plenary session for all participants and teachers. If 
needed, the teachers will upload additional information to the online platform to support the 
participants’ further learning.            
After the teaching seminar a final post-self-test is available (a replication of the pre-self-test for 
teaching seminar 3) for the participants to create awareness about continuous learning process 
and to illustrate to what extend the learning objectives of the teaching seminar have been 

The clinical impact of POCUS use in general practice  
20 
reached. The teachers will reach out to participants, where the test scores reveal problems or 
difficulties, as well as participants, where the demonstration of the scan revealed specific 
difficulties. These participants will be offered additional support.  
 
Participant commitment  
The educational intervention requires considerable commitments from the participants (Figure 
7). This will be outlined in both the course description, the introduction webinar and on the first 
teaching seminar. Participants will have to allocate three whole days for the teaching seminar 
and considerable time to practice scanning skills especially during the training phase (days 8-29).  
Furthermore, time will be allocated to perform assignments and follow the discussion on the 
online platform.  
To ensure this commitment, time will be spent on building group relations on the first teaching 
seminar. In addition, a teacher will be allocated each participant as a mentor during the learning 
process. The mentor will monitor individual progress in the online platform and correspond with 
the individual participant in the chat functions, provide feed-back on assignments and reach out 
to participants, who fail to be active on the online platform.  
 
 
11b 
Criteria for discontinuing or modifying allocated interventions for a given trial 
participant  
The trial may be discontinued for a GP in case of withdrawal of an informed consent. Hence, 
data collection will stop for that person at the time of withdrawal of the informed consent. 
This is an intention-to-treat study hence participants will not be excluded because of low 
adherence to the educational elements. However, we will collect data of the degree of 
participation for each participant and we will include this in the process evaluation (outcomes I1, 
I2, I4 and F5).   
 
11c 
Strategies to improve adherence to intervention protocols, and any procedures for 
monitoring adherence  
The teachers will act as mentors for the participants and monitor participants’ activity on the 
online platform. The teachers will monitor the activity of the participants, they are mentoring and 
reach out to participants, who fail to be active on the online platform or complete assignments.  
 
11d 
Relevant concomitant care and interventions that are permitted or prohibited 
during the trial 
The GPs are asked to refrain from seeking other POCUS education or courses during the study 
(day 1-372). Still, information seeking e.g. through internet sources or books are allowed 
throughout the study.  
 
12 
Outcome measures  
 
Following the educational interventions GPs will return to work in their clinics and use POCUS 
during clinical encounters. GPs can freely choose which patients are relevant and suited for 
POCUS examinations.  
 
Outcomes to assess the effectiveness of the intervention:  

The clinical impact of POCUS use in general practice  
21 
Following the use of POCUS in the general practice consultations the GPs will follow normal 
procedures for registration of activities in general practice using remuneration codes, fee-specific 
codes for using POCUS, and referrals in the medical record system. Prior to this study 11 fee-
specific codes for 11 different POCUS examinations will be installed in the medical record 
system. The Primary Sector Data Provider Platform (PLSP) will develop an algorithm that 
allows for the following data extraction on each participating GP in a given time frame: (1) 
number of POCUS examinations performed, (2) number of referrals, and (3) number of 
consultations (outcomes E1-3). PLSP will deliver monthly aggregated data for each participating 
GP from baseline to 24 months after baseline. These continues data will be summarized to 
demonstrate variation over time.  
 
For the registration of the clinical effect of POCUS use in the consultation (outcome E4), we will 
use an adapted version of a questionnaire used in a previous cohort study24. The GPs will be 
asked to specify the following for each POCUS examination: (1) organs/structures examined 
with POCUS (drop down menu or free text), (2) whether POCUS use entailed a change in 
diagnosis (yes/no), (3) whether POCUS use entailed a change in referral (yes/no), (4) whether 
POCUS use entailed a change in treatment (yes/no), (5) whether POCUS use entailed a change in 
diagnostic certainty for the GP (yes/no), (6) whether POCUS use was helpful for the GP in terms 
of making a decision for patient management (5-point Likert scale), (7) whether POCUS use was 
helpful for the GP in terms of arriving at a diagnosis (5-point Likert scale). GP will assess the 
questionnaire immediately after performing POCUS during consultations in clinical practice. 
These categorical data will be collected for each participating GP from day 7 to day 372.   
 
For the registration of unwanted cases (outcome E5), we will use a questionnaire giving the GPs 
the possibility to explain in free text using their own words to explain (1) what was scanned, (2) 
circumstances surrounding the scan, (3) what happened, and (4) reflections after the scan. Data 
will be collected from baseline to 24 months after baseline. We will report the aggregated total 
number of monthly registrations for each participating GP. The free text elaborations will not be 
reported, but passed on to the safety committee (see section 5d). The assessment of unwanted 
cases for the study does not substitute the GP’s registration of untoward incidents required by 
Danish law (https://stps.dk/da/ansvar-og-retningslinjer/vejledning/rapporteringspligt/).  
 
Outcomes to assess implementation strategy effects:  
For the assessment of implementation strategy effects (outcomes I1-4), we will use the register 
data (fee specific codes) collected by PLSP on the monthly use of POCUS for each participating 
GP (outcomes I1 and I4) and the activities logged (pre-post tests, webinars, assignments, 
attendance on seminar days, logbook registrations) in the online platform used in the educational 
intervention (outcomes I2-3) to estimate the frequency of use and the percentage of adherence, 
respectively. The continues data (outcomes I1and I4) will be collected prospectively from day 7 
to day 372, while the binary data (outcomes I2 and I3) are collected retrospectively at the end of 
the educational intervention including registration made in the online platform from day 1 to day 
97 (at the end of the educational intervention).  
 
Outcomes to inform further development of the implementation strategy 
For outcomes related to the development of the implementation strategy (outcomes D1-D11), we 
will use a questionnaire distributed to participants three months after introducing POCUS in 

The clinical impact of POCUS use in general practice  
22 
general practice and teachers following the final teaching seminar (day 97). A reminder will 
follow after 2 weeks. The questionnaire will include the following questions with a 5-point 
Likert scale:   
(D1) Did the educational intervention meets local needs?  
(D2) Was the educational interventions agreeable in terms of content and delivery?  
(D3) Was the educational intervention suitable for implementation?  
(D4) Was the educational intervention in line with your values, mission, priorities?  
(D5) Are you satisfied with the amount of support and resources allocated to you? 
(D6) Was the educational intervention too difficult or complex to implement?  
(D7) Did any organisational political, economic or social factors influence the 
implementation of the educational intervention? 
(D8) Did the setting, including organisational values or norms influence the 
implementation of the educational intervention?   
(D9) Did you have the capacity (e.g. knowledge and skills) to implement the educational 
intervention?  
And the following questions with a free-text answer category:  
(D10) How must did you have to invest financially to implement the educational 
intervention?   
(D11) How much time and resources did you have to invest to implement the educational 
intervention?   
 
Outcomes to assess the feasibility of trial methods 
For the assessment of the feasibility of trial methods (outcomes F1-F8), we will evaluate the data 
quality by calculating the proportion of missing or incomplete registrations, recruited participants 
in relation to possible number of participants as well as participant retention and adherence. The 
steering committee will discuss the results and perform a qualitative evaluation based on 
predefined progression criteria (see section 16c).  
Regarding the GP questionnaire (outcome F8), we will pilot test validated scales to determine 
GPs’ perceived stress (Cohen’s 10-item Perceived Stress Scale), GPs’ job satisfaction (Warr-
Cook-Wall Job satisfaction Scale) and GPs burnout symptoms (Maslach Burnout inventory). 
Prior to the study, these questionnaires were tested for face validity in four focus groups with 18 
POCUS using GPs (unpublished materiel). The Cohen’s 10-item Perceived Stress Scale includes 
ten items about the frequency of stress-related feelings and thoughts. Each item is rated from 0 
(never) to 4 (very often). Previous research has reported a sum score of ≥ 18 to be a high level of 
stress25.  The Warr-Cook-Wall Job satisfaction Scale includes 9 sub-items measuring facets of 
job satisfaction and one overall item rated on a scale from 1 (extreme dissatisfaction) to 7 
(extreme satisfaction). In previous research25 a cut-off on the overall item of ≤ 3 has been used to 
identify low job satisfaction. The Maslach Burnout inventory consists of 22 items exploring the 
following three burnout dimensions: (1) emotional exhaustion (9 items) characterised by 
depletion of emotional resources, (2) depersonalisation (5 items) characterised by emotional 
detachment from people related to work including patients and (3) personal accomplishment (8 
items) including perceived value of work and self-efficacy. All dimensions are rated on a scale 
from 0 (never) to 6 (every day). A sum score is calculated for each dimension. The GP 
questionnaire will be distributed to participating GPs prior to the third teaching seminar (day 37, 
at the end of the educational intervention).  

The clinical impact of POCUS use in general practice  
23 
 
 
Participants characteristics 
On the first teaching seminar (day 7) the following participant characteristics will be collected: 
Age (years), gender (M, F, other), previous use of ultrasound (number of months with regular 
use), previous ultrasound courses of minimum 1 day duration (yes/no), scanner type (low range, 
mid-range, high end), type of practice (collaboration, partnership, solo), location of practice 
(urban, rural, mixed), number of patients assigned to the practice, number of GPs working in the 
practice. 
 
From PLSP, we will receive the following aggregated data on patients (age, gender) calculated 
based on patient ID in the medical records in the clinics (CPR numbers). These data are extracted 
and transferred to CAM AAU anonymously.   
 
 
13 
Time schedule  
We will invite participants from two PLO-e ultrasound course to participate:   
Teaching seminars course 1: August 31st and September 28th and November 30th 2022 
Teaching seminars course 2: September 6th and October 10th and November 29th 2022 
 
 
Data collection participants in course 1: August 24th 2022 to November 30th 2024. 
Data collection participants in course 2: August 30th 2022 to November 30th 2024. 
 
14 
Sample size  
This is accompanying research and as such no formal sample size calculations are made. Our 
potential study population is 36 GPs, who have signed up to participate in an ultrasound course 
organized by PLO-e. We expect a participation rate of 66% corresponding to 21 GPs. Previous 
cohort studies from Danish general practice have shown that GPs’ average use of POCUS 
corresponds to once a day. With a data collection period of 24 months for participants 
corresponding to 200 working days, we expect approximately 8400 POCUS registrations in this 
study.  
 
15 
Recruitment  
Two ultrasound courses delivering the educational intervention have been included in PLO-e’s 
course catalogue for 2022 and as such all GPs working in Danish general practice has had the 
opportunity to sign-up for the courses. PLO-e has handled the participant recruitment and 
registration based on a first-come-first-served principle as well as the financial and practical 
aspects of organizing and executing the courses. The two ultrasound courses have a total of 36 
available spots and all 36 participants are offered the opportunity to participate in the data 
collection for this study. However, not all participants will be offered financial compensation for 
participating in the study, as a collective agreement between the Danish regions and the 
association of GPs only allows for those GPs with in longest distance to a radiology department 
to have a free course attendance and a fee for performing POCUS during the data collection.   
 

The clinical impact of POCUS use in general practice  
24 
The offer to participate in the study is made upon registration to the course and repeated at the 
first webinar (day 1). At the webinar participants are informed about the research project and 
written information about the project including a consent form is distributed to participants. The 
signed consent forms are collected from participants on the first training seminar (day 7).  
Assignment of interventions  
16a  
Allocation Sequence generation 
n/a 
16b 
Allocation concealment mechanism 
n/a 
 
16c 
Implementation 
After the educational intervention, we will perform a process evaluation by collecting and 
assessing a number of implementation-related outcomes. We will use predefined progression 
criteria for all outcomes to make an interim analyses and evaluate whether adaptions to the 
intervention is needed prior to the large stepped wedged cluster randomized clinical trial (SW-
CRT). The steering committee will perform this evaluation.  
 
We will consider changing the intervention and/or implementation strategy if:  
 
Implementation strategy effects: 
(I1) Adoption: less than 80% percent of participating GPs adopt the intervention and start 
using POCUS in their daily practice during the educational interventions (months 1-3).   
(I2) Fidelity (adherence): less than 75% of participating GPs complete the educational 
elements in the intervention (pre-post tests, webinars, assignments, attendance on seminar 
days, logbook registrations). 
(I3) Reach (penetration): less than 90% of teachers will actively support participants by 
engaging in the online part of the educational interventions  
(I4) Sustainability (maintenance): less than 75% of participating GPs adopt the 
intervention and continue to use POCUS in their daily practice following the educational 
interventions (months 5-6).   
 
Development of the implementation strategy 
(D1) Adaptability: Less than 90% of teachers or participants find that the implementation 
of the educational intervention meets local needs  
(D2) Acceptability: Less than 90% of teachers or participants find the implementation of 
the educational interventions is agreeable in terms of content and delivery  
(D3) Feasibility: Less than 90% of teachers or participants find the educational 
intervention to be suitable for implementation  
(D4) Compatibility (appropriateness): Less than 90% of teachers or participants perceive 
the implementation of the educational intervention to be in line with the organisation’s 
values, mission, priorities  
(D5) Dose (satisfaction): Less than 90% of teachers or participants are satisfied with the 
amount of support and resources received as part of implementation strategy 

The clinical impact of POCUS use in general practice  
25 
(D6) Complexity: More than 90% of teachers or participants perceive the implementation 
of the educational intervention as being difficult or complex  
(D7) Context: More than 90% of teachers or participants find that organisational political, 
economic or social factors influenced the implementation of the educational intervention  
(D8) Culture: More than 90% of teachers or participants find that the setting, 
organisational values or norms influenced the implementation of the educational 
intervention   
(D9) Self-efficacy: Less than 90% of teachers or participants find that they had the 
capacity (e.g. knowledge and skills) to implement the educational intervention  
(D10) Cost: if costs of implementation the educational intervention exceeds the budget 
for the research project    
(D11) Resources: if measures of the resources and managing required for the 
implementation the educational intervention exceeds the budget for the research project    
  
Feasibility of trial methods 
(F1) if we are not able to recruit 66% of the eligible participants   
(F2) if we are not able to retain 66% of participants   
(F3) if we are not able to retain 90% of teachers  
(F4) if less than 90% of teachers delivered the intervention by protocol  
(F5) if less than 90% of participants received the intervention by protocol  
(F6) if less than 90% of data from registers was obtainable and valid 
(F7) if less than 90% of data collection through GP questionnaires was obtainable and 
valid 
(F8) if less than 90% of data collection through GP questionnaires was obtainable and 
valid 
 
 
17 
Blinding  
The researcher cleaning the data set and responsible for analyzing the primary outcome will have 
no knowledge of participants. He is a researcher with a physiotherapy background. 
Data collection, management, and analysis 
 
18a 
Data collection - Plans for assessment and collection of outcome, baseline, and other 
trial data 
Data will be collected at different timepoints.  
 
Figure 7. Data collection  
 

The clinical impact of POCUS use in general practice  
26 
 
 
 
Register data: Data regarding different POCUS examinations, number of referrals, number of 
consultations will be delivered by PLSP (outcomes E1-3, I1 and 4). The data are registered prospectively 
by GPs in the medical records during the consultations from the first teaching seminar (day 7) until 24 
months after the first teaching seminar (day 829). We will receive these data retrospectively from PLSP, 
who will use an algorithm to collect monthly aggregated data for each participating GP.    
PLSP will also deliver aggregated data on patients age and gender independent from other study data.  
 
GP registrations: For the GPs’ registration of POCUS effect in the consultation (outcome E4), GPs will 
use paper registrations in logbooks during the educational intervention (day 7 to 96). Here the 
registrations are made for the GPs own purpose as part of the learning process. Following the educational 
intervention, we will ask the GPs to continue making these registrations with the purpose of research, 
using a QR code to access an online questionnaire. The paper registrations will be collected by the 
research team at the third teaching seminar (day 97) while the online-questionnaire data are collected 
continuously from day 97 to 372.  
For the reporting of anonymously unwanted cases, GPs will have a QR code and a link for an online 
questionnaire (outcome E5). These data are collected prospectively continuously during consultations 
from the day 7 – day 829.  
 
GP questionnaire: For the pilottest of a cross-sectional questionnaire exploring burnout, stress and job 
satisfaction at 3 months (outcome F8), an online questionnaire will be distributed to participants 
following the third seminar day and a possible reminder will follow after two weeks. The questionnaire 
collecting background characteristics on participating GPs will be distributed on the first teaching seminar 
(day 7).  
 

The clinical impact of POCUS use in general practice  
27 
Online platform: For the evaluation of participant adherence (outcome I2) and reach (outcome I3) we will 
use the registrations on the online platform (Microsoft Teams) supporting the educational intervention. 
These are collected retrospectively at the end of the educational intervention (day 97).  
 
Process evaluation questionnaire: For the evaluation of implementation of the educational intervention 
(outcomes D1-11) a questionnaire will be distributed to teachers and participants following the 
educational intervention (day 97).  
 
18b 
Data collection - Plans to promote participant retention and complete follow-up 
During the study, the principal investigator is available for consultation for the participating GPs 
in order to resolve any problems or obstacles. Reminders will be sent to the participating GPs 
reminding them to scan patients and contact the research team in case of problems.   
 
19 
Data management 
The data management will follow the rules of the General Data Protection Regulation (GDPR) 
and the Danish Data Protection Agency. All study data will be stored on a secure server at 
Aalborg University. Questionnaire data will be collected using the online platform SurveyXact 
(Rambøll, Aarhus, Denmark). A data management agreement has been made between Rambøll 
and Aalborg University. At the end of the data collection, data will be moved from SurveyXact 
to Aalborg University’s server.    
Register data will be collected by PLSP. Data management agreements between PLSP and CAM 
AAU will be made prior to the collection of data. PLSP will receive data from the different IT 
suppliers for the general practice clinics. Data management agreements between the IT suppliers 
and PLSP as well as the GP clinics and the IT suppliers already exists. For this specific study, we 
will develop an instruction for the GPs to incorporate in the existing data management agreement 
prior to the collection of data.   
All patient-related data will remain in the GPs clinics until the end of the educational 
intervention (day 97). No data will be transferred to CAM AAU before legal approval by the 
health authorities has been obtained.   
 
20a 
Statistical methods for analysing primary and secondary outcomes.  
All statistical analyses will be performed using STATA version 17 (StataCorp, Texas, USA) and 
analyzed according to a predefined statistical analysis plan, which will be uploaded to clinical 
Trials.org prior to the analysis of data (24 months after baseline). Data will be summarized and 
reported using descriptive statistics.  
 
For effectiveness related outcomes E1-E5, frequencies and variance are reported as mean and 
95% CI or median and IQR depending on the distribution of data. We will use graphic 
illustrations to demonstrate change over time. To test if changes over time are significant, we 
will use repeated measures ANOVA analysis.   
 
For outcomes related to the implementation strategy effects (I1-I4) and feasibility of trial 
methods (F1-F7), we will report proportions as frequencies, while outcomes related to the 
implementation strategy (D1-D9) will be reported with an average score and outcomes D10-D11 
with a summarized estimate on costs. For fesability related outcome F8, we will report the 
questionnaire response rate and the corresponding 95% CI.  
   

The clinical impact of POCUS use in general practice  
28 
20b 
Methods for any additional analyses (e.g. subgroup and adjusted analyses). 
We will perform subgroup analysis to explore the effects of participants’ background 
characteristics and type of POCUS examinations performed. This will be elaborated in the SAP.  
 
20c 
Missing data  
Missing values, owing to e.g. premature termination of the questionnaire, are considered 
completely random and will be declared for each outcome.  A sensitivity analysis will be 
performed in cases, where missing values are not considered random. 
 
Data monitoring 
 
21a 
Data monitoring committee (DMC). 
The principal investigator (CAA) will monitor the data collection and contact the project steering 
committee in case of problems related to data collection or the validity of the collected data. The 
principal investigator (CAA) will also contact the steering committee in care of participant drop-
out.    
 
21b 
Description of any interim analyses and stopping guidelines, including who will have 
access to these interim results and make the final decision to terminate the trial 
n/a 
 
22 
Harms  
 
The participating GPs will be obliged to report any undesirable effects including Suspected 
Unexpected Serious Adverse Reactions (SUSARs), Serious Adverse Events (SAEs) and Adverse 
Events (AEs) related or possibly related to the use of POCUS to the safety committee.  
 
23 
Auditing 
n/a 
Ethics and dissemination 
24 
Research ethics approval 
The study will be performed in accordance with the Declaration of Helsinki. The project was 
notified to The North Denmark Region Committee on Health Research Ethics. 
(Den Videnskabsetiske Komité for Region Nordjylland, reference number 2022-000764) who 
responded that according to Danish Law (komitélovens § 14, stk. 2), no ethical approval is 
needed for this project.  
As we are collecting patient-related data for the purpose of research, we will seek permission by 
the health authorities (Application sent October 13th 2022). All patient-related data will be 
collected retrospectively after this approval is obtained. We will honor our information 
obligations to patients about the project by making project information available in the GP’s 
clinic as hand-outs and posters.     

The clinical impact of POCUS use in general practice  
29 
The project has been registered and conducted according to the regulations of the Danish Data 
Protection Agency (registration number ID 242-3).  
 
25 
Protocol amendments 
 
This is the second version of the study protocol. An amantment has been made prolonging the 
study follow-up for the primary outcomes to 24 months instead of 12 months. This was done, as 
register-based data was not made available until November 2024. Consentforms and permissions 
did allow for this extension.  
 
26a 
Consent or assent 
 
Informed consent form the participating GPs will be collected by the principal investigator prior 
to the study. We will not seek consent from patients, as no collected study data are directly 
linked to the specific patient. This decision was made to enable us to collect data on all patients 
examined with POCUS in general practice during the study, including patients who are unable to 
provide informed consent (children, elderly, and patients with mentally handicap).     
 
26b 
Additional consent provisions for collection and use of participant data and 
biological specimens in ancillary studies, if applicable 
n/a 
 
27 
Confidentiality 
 
Personal information about participants consenting to participate will be stored on a secure 
server at Aalborg University. All data will be kept for 10 years after completion of the study 
which in accordance with The European Code of Conduct for Research Integrity.  
 
28 
Declaration of interests 
The authors declare that they have no competing interests. 
 
29 
Access to data 
The following authors will have access to collected data stored at the secure server at Aalborg 
University (AR, MBJ, JJS, SLC and CAA).  
 
30 
Ancillary and post-trial care 
 
Any participants who suffer harm from trial participation will be eligible to seek compensation 
by The Patient Compensation Association.  
 
31a 
Dissemination policy  
We aim to publish positive, negative or inconclusive results of the study in a peer-reviewed 
journal. The project group will also present results at conferences.  
We aim for two scientific publications: Article 1 will include effectiveness-related outcomes 
(E1-E6), while Article 2 will report the development of the intervention and implementation-
related outcomes (I1-4, D1-11 and F1-7).  
 

The clinical impact of POCUS use in general practice  
30 
31b 
Authorship eligibility guidelines  
We follow the definition of authors defined on ICMJE´s four criteria1:  
 
• 
Substantial contributions to the conception or design of the work; or the acquisition, 
analysis, or interpretation of data for the work; AND 
• 
Drafting the work or revising it critically for important intellectual content; AND 
• 
Final approval of the version to be published; AND 
• 
Agreement to be accountable for all aspects of the work in ensuring that questions related 
to the accuracy or integrity of any part of the work are appropriately investigated and 
resolved. 
 
31c 
Plans for granting public access to the full protocol, participant-level dataset, and 
statistical code 
It is unsure if data can be anonymized sufficiently to be made publicly available. 
 
32 
Informed consent materials 
Danish informed consent form will be developed and used in the study.    
 
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