Frequently asked questions (FAq)

Below please find answers to some frequently asked questions. If you have any questions, do not hesitate to send them to  

Q: If there is no INR recorded, and no mention of end stage liver disease, can the patient be included in the study?
A: If the patient doesn’t have ascites and encephalopathy, and INR is missing, calculate the worst case scenario based on the bilirubin and albumin levels alone. Even if both albumin and INR are missing, the CP score cannot be worse than 9 (CP class B) if bilirubin is normal and there is no ascites or encephalopathy.

Q: Is it possible to have some flexibility on the exclusion criteria of 'Child Pugh C  end stage liver disease'?
A: The exclusion criteria is written in the protocol so we are limited by that. But you can use the most recent bilirubin, albumin and INR results. If there is no mention of ascites or hepatic encephalopathy or end-stage liver disease (or decompensated liver disease) in the patient chart, there is no need for a clinician to examine the patient for ascites and encephalopathy.

Q: Does the creatinine clearance measurement have to be taken within the last 3 months?
A: Previously, this was a requirement in REDCap, however this has now been changed to the last measurement taken.
Q: Is it important to collect information about the particpants´ weight?
A: Weight should be available because it is required to calculate eGFR which is one of the inclusion criteria 

Q: When should Patient Baseline Data be completed?
A: Patient Baseline Data should be completed immediately after the patient has consented to participate in the study. This form contains critical information on eligibility criteria and informed concent, so we ask this is filled out as early as possible.
Q: Should the study staff or the patient complete the questionnaire?
A: The questionnaire should be completed by the study staff.
Q: Is a print version of the questionnaire available?
A: A print version of the questionnaire can be found at the website ( together with many other study documents.
Q: Can blood samples be taken before the patient has given a stool sample?
A: No, the patient must deliver a stool sample before blood is taken. As the primary aim of this study is to investigate microbiome related factors associated with serious AIDS and non-AIDS events, collection of the faecal sample is of utmost importance. Stool samples should be returned to the lab within 48 hours of defacation and blood samples can be taken after the stool sample has been returned.
Q: Must the patient take home the stool kit and do the stool sample at home?
A: Not necessarily. If possible, the stool sample can be taken the day of the visit, as long as the patient has given consent to participate in the study beforehand.

Q: A participant consents and takes the stool sample collection kit home with them, when do they have to return?
A: The participant has to return to the clinic with their stool sample within 48 hours of defacation. This should occur as early as possible to the consent, to ensure eligibility criteria are still met at time of sample collection. However, we allow up to 3 months from date of concent for the participant to collect the stool and return the sample to the clinic.

Q: Can a patient be enrolled in other studies while being part of MISTRAL?
A: MISTRAL is a purely observational study, so patients may participate in other trials while also being enrolled in MISTRAL.

Q: Do the sample labels match, in any way, with the participants’ PID numbers?
A: No, you should use one set of labels per participant per visit in the order that you receive the samples. The labels will then be linked to the correct participant and visit when they are scanned into REDCap. You will also need to record which label IDs belong to which patient on the site List of Stored Samples. For more information see slide 43-48 in the Training slides.

Q: What is the difference between the MISTRAL follow-up form and the MISTRAL follow-up visit?

A: The MISTRAL follow-up visit is the 2nd visit for all participants, during which the visit questionnaire is completed and stool, plasma and whole blood are collected for the second time (here in REDCap). This should occur 10-24 months after the 1st visit (i.e. stool collection date).  
The MISTRAL follow-up form is an annual follow-up form (here in REDCap), which, like the EuroSIDA follow-up form, collects updated clinical data since a participant’s enrolment form, but only for non-EuroSIDA participants. EuroSIDA MISTRAL participants continue to complete the EurosIDA follow-up form as usual. We have set the deadline to complete the MISTRAL follow-up form by 1st December 2023 (only for those patients whose enrolment form was completed and verified by us before 1st July ’23). If you do not have any new information, then write so in the follow-up form Section A, and remember to mark the status as ‘complete’.