FAQ participating centers - STOP Leg Clots


  1. Which patients can be included?

Patients aged between 18-75 years, with an acute injury requiring lower-leg immobilization, i.e. acute unilateral Achilles tendon rupture or isolated ankle fracture, that does not have any exclusion criteria, will be eligible. All fracture types, except “pilonfractures”, may be included.

  1. Which are the exclusion criteria?

1. Inability to give informed consent. 2. Inability to follow instructions. 3. Planned follow-up at another hospital. 4. Known renal failure. 5. Heart failure with pitting oedema. 6. Known malignancy. 7. Known haemophilia or thrombophilia. 8. Known current thromboembolic event. 9. Pregnancy. 10. Not suitable for orthosis treatment.

  1. When does inclusion/randomization to treatment have to be done?

Inclusion and randomization to the study must be done within 10 days from the injury.

  1. What are the patients randomized to?

Half of the patients will be randomized to “Treatment as usual without IPC”. This means the treatment that patients usually receive, even if there was no study at the clinic. The other half will be treated with "Addition of IPC treatment". This means that the patient will receive the AirCast Airselect Elite orthosis as lower leg immobilization directly following surgery. The orthosis is applied together with the associated IPC device that each clinic will lend to the patient.

  1. Can patients have pharmacological thromboprophylaxis and still be included in the study?

Yes. If pharmacoprophylaxis is prescribed, please record the substance given and the duration of treatment. Pharmacoprophylaxis for deep venous thrombosis in patients with lower-leg immobilization has, however, demonstrated low or non-effectiveness, presumably due to the low blood circulation in the immobilized limb. Therefore, this study will investigate the effect of adjuvant mechanical thromboprophylaxis, i.e. IPC.

  1. How do I include/screen the patient?

What you first have to do is to fill in a screening form at https://redcap.ki.se, login to this page has been arranged for each hospital separately (see the section below on REDCap). Once you have logged in, select "Add / Edit records" in the left column to add a new patient.

  1. Which patients should be screened for inclusion into the study?

If a patient in the emergency room, after receiving information of the study, shows interest in participating in the study, the patient should be screened for inclusion. A patient who not wants to enter the study should not be screened for inclusion.

  1. A patient with an ankle fracture wants to be included in the study, but the ankle is too swollen to be operated on right now. Should we screen the patient now or wait to see if we can randomize within 10 days?

If the patient wants to be included in the study then he/she should be screened for inclusion. If the patient cannot be randomized within 10 days due to the swelling, this should be stated in "other cause of exclusion" on the screening form.

  1. Should all screened patients be registered in REDCap?

Yes, all screened patients must be registered in REDCap. If the patient does not want to participate after being fully informed about the study, then the reason why the patient does not want to participate should be stated in "other reason for exclusion" in the screening form.

  1. Does it have to be a doctor that includes/randomizes the patient to the study?

No. However, the person should be involved in the local study group.

  1. Which forms must be filled in to be able to randomize the patient?

Inclusion screening and the patient's email must be filled in under "Patient information" (if the patient has an email) before you can fill in the form "Randomization". Email is important to fill in before randomization in order for the automatic emails to work properly.

  1. What can you do if the patient does not have any email/computer/smartphone?

Then the patient gets the necessary diaries in paper format. These diaries are important to collect when the lower leg immobilization ends. It is also important that you send out paper surveys manually at 6 and 12 months.

  1. What information should the patient bring home after the recruitment?

The patient must sign a consent for the participation in the study. Thereafter, the patient receives the full information about the study with contact information to the person locally responsible, load diary and the time-point for the return visit. If the patient is randomized to IPC, they should additionally recieve the IPC-device including cables + cuffs + IPC diary.

  1. How does the IPC-machine and orthosis work?

This is described in the Youtube video:  https://youtu.be/TthMTeATPUA (soon in English)

  1. How do I know that the patient will return the IPC-machine?

It is important that the patient signs an agreement (link to agreement will come) when the IPC machine is handed out. Upon return, this is signed on the agreement.


  1. When should the patient have the first revisit?

The first revisit will be the healing control at the hospital approximately 10-14 days after the injury. The status of the limb (signs of infection or DVT) and of the leg immobilization is controlled and the diaries of the patients are controlled.

  1. Is there any template for the general visits you can use?

Templates for the first and second visits are available at:  https://ki.se/en/mmk/information-to-participating-centers-slc 

  1. If the patient according to local routines during a revisit should change from a plaster cast to an orthosis, is this ok?

Yes, as long as this is documented and reported in REDCap.


  1. How do the 6 and 12 months follow-up work?

If the patient has an email address registered in REDCap, the questionnaires he/she needs to fill out will automatically be sent to the patient at these time-points. The patient can fill in these questionnaires electronically. However, the study personnel have to check that the patient did fill in the questionnaires. Otherwise the study personnel have to contact the patient and in some cases make additional appointments.

  1. Should patients undergo any additional testing during follow-up?

Some hospitals will perform additional testing, however, this does not apply to all hospitals.

Exit from the study / Exclusion

  1. A patient has been incorrectly included or does not longer want to be included in the study. How do I handle this?

This must be registered in REDCap under the instrument "Exit from the study/Exclusion". If the patient self chooses to terminate participation, there is no need to state a reason, but if the patient does state a reason, this should be documented. If the patient is incorrectly included, the reason should always be stated.

  1. A patient wants to quit using the IPC-device, should I exclude the patient from the study?

No! The Data collected in the study will be analyzed as ”Intention-to-treat”. The patient can therefor still be a part of the study, even though he/she is not using the pump anymore. The patient should perform the ultrasound screening after discontinuation of immobilization if he/she still wants to.


  1. How do I access REDCap?

Instructional Video:  https://www.youtube.com/watch?v=TmDdi54GZEE  (soon in English).

  1. Something seems wrong in REDCap when I try to fill in information.

Please, contact Simon Svedman. Contact information is available under “contact us”.

  1. How do I add information to an existing patient's file in REDCap?

This can be done in 2 ways:

1. In the left panel, select “Record status Dashboard”. This dashboard contains the status of all patients you have included. Then press the “status button” for the patient and the examination you want to fill in/change. The status button will become green if you select "Record is complete" and red if you select "Record is uncomplete" at the end of the questionnaire.

2. Select "Add/Edit Records" in the left panel. Then select the patient's ID number from the list. Thereafter you can choose to which survey you want to add/correct data.

  1. I try to make corrections to a patient's data, but this is not possible because the examination is locked. How do I fix this?

Contact Simon Svedman or Luigi Belcastro and describe the issue and they will help to resolve the problem.


  1. We use probes/machines other than those specified in the ultrasound protocol? Do we have to change?

No, use the probes/machines used in your clinic.

  1. Must the patient be positioned as described in the protocol?

No, position the patient as you normally do in your clinic. The most important thing is that the examiner feels comfortable that the examination is performed correctly.

  1. Should any special form be filled in during the survey?

Yes, we have an example of what an ultrasound Case Report Form should look like for this study, (see below). 

  1. Do the ultrasound examinations have to be sent to Karolinska Solna?

All positive examinations should be sent to Karolinska Solna after the study has been completed. This can be done on e.g. a CD or USB.


  1. How does each hospital get paid for included patients?

Billing for included patients takes place every half year, in March and September. More information can be found at: Invoicing Karolinska Institutet | Karolinska Institutet (ki.se). Under ”reference”, please write: ZZK1DISTAV. Also, please specify what the invoice is in regards to (project STOP Leg Clots, number of patients that have completet ultrasound screening, number of patients that have filled in the 1 year questionnaires.


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