Study Setting
The Balgrist University Hospital in Zurich is a tertiary referral center for orthopedic surgery and affiliated to the University of Zurich. It has a multi-disciplinary team composed of orthopedic surgeons, internists, infection control nurses, and infectious diseases physicians who are all specialized in orthopedic infections. Moreover, this team is accompanied by the Unit for Clinical and Applied Research (UCAR) with experience in investigative designs. The UCAR engages 4 study nurses and 3 research assistants specialized in clinical trials.
The decolonization set - Product
Schülke & Mayr will donate 550 decolonization sets for free use for the BALGDEC trial.
We will use these prefabricated set [7, 8] that contain patient’s information leaflets available in German, English, French and Italian languages. The active ingredient contained in both products (octenisan® wash lotion and octenisan® md nasal gel; both products combined in octenisan® set) [8] (no. article 11636528, EAN 4032651979264) is octenidin dihydrochloride. One set would cost 22,25 Swiss Francs on the market [8]. The wash lotion is applied once a day; and rinsed with water after application. The nasal gel is applied 2–3 times per day [7, 8]. The sets can be stored at ambient temperature for several months, as indicated on the packaging. The study sets will be locked in the office of the Infection Control nurses and in the PI’s (Principal Investigator) office. There is no public access to these offices without individual keys.
Study Objectives
We aim to reduce the incidence of SSI (and other unplanned postoperative wound revisions) in adult orthopaedic patients with an elevated risk for SSI. We equally investigate the safety of the presurgical decolonization, and the difficulties of its application, in daily clinical life.
Study Criteria, Definitions, and Study Outcomes
The Tables 1 and 2 resume key definitions and the outcomes of the trial. Only adult, elective orthopedic surgery patients, with a focus on high risk for revision and/or SSI, will be included. This particular patient population resumes: chronic immune-suppressions of any type, patients with American Society of Anesthesiologists’ (ASA)-Scores of 3–4 points or with an age of ≥ 80 years; independently of the presence of an orthopedic implant. The Fig. 1 resumes the Study Criteria and Fig. 2 the Study Flowchart. We define a SSI as the microbiological evidence of the same bacteria in at least two intraoperative tissue samples together with radiological (osteitis, collections, inflammation) and/or clinical evidence of infection (pus, discharge, sinus tracts, rubor, calor, pain). The presence of a histological proof is facultative. Postoperative wound problems are any unexpected problems that persist, or re-emerge, after ten days following the elective orthopaedic interventions. We define implants as any foreign material; except for allografts, wires or fixator pins. "Remission" is the absence of clinical, and/or radiological, and/or laboratory signs of infection after a minimal follow-up time of 6 weeks for soft-tissue surgery; or 1 year for implant-related and/or bone surgery.
Table 2 - Outcome parameters and assessments of the randomized trial
Primary outcome (composite outcome)
- Remission (and inversely superficial or deep-space SSI and revision surgery for postoperative wound problems) at 6 weeks (and/or a 1 year for surgeries with implant).
Secondary outcomes:
- Unplanned revision surgery for non-infection problems in same time period.
- All adverse events during decolonization and hospitalization for surgery.
- Subjective opinion on the decolonization (only for patients being decolonized; using a questionnaire).
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Assessment of outcomes
Prospective assessment by the infection control team during hospitalization. Retrospective assessment by study nurses and surgeons during the surgical controls after hospitalization. These surgical controls are regularly scheduled at 6 weeks and 1 year postoperatively; independently of our study.
Interventions and Study Conduct
The BALGDEC trial is a single-center trial, starting on 27 February 2023. The operational study team will screen eligible patients during the presurgical orthopedic and anesthesiologic consultations, which usually take place between 3 and 10 days before scheduled surgery.
All clinicians may screen for eligible patients and inform them about the BALDGDEC trial. However, only the Infection Control Nurses and the Infectious Diseases Physician will provide specific instructions regarding the decolonization measure and randomize the included patients (1:1) to the “decolonization set” or no medical decolonization. The study team will hand over the set at enrolment, together with an in-house questionnaire. The randomization procedure uses prefabricated cards and is performed by a study nurse who is not involved in the enrolment process (central telephone). There will be no blinding and no placebos. Each surgery counts as an independent event. During the two years that we plan for this trial, one patient can participate several times as long as his/her orthopedic surgeries are independent from each other.
Decolonization Procedure
The duration of the pre-surgical decolonization is five days. When this period is too short, the decolonization may also start 3 days before surgery and be continued until Day 2 post-surgery. For hospitalized patients, or patients in elderly homes, the nurses might apply the products. Likewise, for patients with cognitive disabilities, an instructed family member can also decolonize. During decolonization, patients shall change bed linens; and the underwear every day. They must not share towels, clothes and other textiles with family members or pets. They must not use other topical antiseptic products on the skin, body lotions or moisturizers. However, the study patients are allowed to use habitual parfums. The patients will return the empty/used sets and answer to a questionnaire that we handed over. The study team will recuperate the questionnaire during hospitalization and fill in lacking responses bed-side; and together with the patient. We aim a return rate of the questionnaires of at least 90%. In the BALGDEC study, we purposely renounce on routine microbiological assessments of skin colonization, because most SSIs are due to usual skin commensals. We screen patients only for the carriage of antibiotic-resistant pathogens, if they correspond to recommendations of the Swiss Infection Control Guidance (www.swissnoso.ch) [12].
Accountability Of The Decolonization Set
We recuperate the empty packages of the used decolonization sets from the decolonized patients shortly after surgery. This process will be documented (accountability log). This log also serves to record any damages of the set. The empty sets will be archived, during the trial, in a side room annex to the Infections Control nurses; and destroyed after the end of the trial. If the returned packages are not empty, we will not use the content for other patients.
Procedures at each visit
At enrollment (Visit 1 / Day 1), we will randomize the included patients at a ratio of 1:1 into the investigational group (decolonization) and the control group (no decolonization). The study investigators will instruct the correct decolonization procedure and distribute the questionnaire to the decolonization group. The study period includes the following study visits (Table 3):
Study Period
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Screening/ Baseline*
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Visit 1*
Enrolment
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Visit 2*
End-of-Treatment
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Visit 3
Test-of-Cure
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Follow-up for surgeries with implants
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Table 3
Study Assessments during the Visits
Time
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Day − 30 to 0
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Enrolment
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Surgery day, or 1–2 days after surgery
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6 weeks
(+/- 14 days)
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1 year
(+/- 2 months)
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In-/ Exclusion criteria
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X
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X
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Informed consent
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X
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X
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|
|
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Demographics / history
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X
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X
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Concomitant medication
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X
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X
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X
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X
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Randomization
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X
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X
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|
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Handing out of the
decolonization set
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X
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X
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X
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Questionnaire
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X
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X
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Assessment of compliance
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X
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X
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X
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X
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Adverse Events
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X
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X
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X
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X
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Study End
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X
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X
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• Visit 1 - Enrollment (Day 1)
• Visit 2 - End-of-Treatment (EOT) - Day of Surgery; or Day 1–2 after surgery
• Visit 3 - Test-of-Cure-Visit (TOC) (Clinical Surgical Control) - Day 42 (+/- 14 days)
• Follow-up for implant-related or bone surgery after 1 year (+/- 2 months).
Enrolment (Visit 1)
The information collected during the routine pre-surgical consultation, and during orthopedic surgery, is not study-specific. This general data will be used as general demographic information and medical history within the study; in case of study participation. If a patient appears to be eligible the following study-specific procedures are performed:
1. Patient information and obtaining written informed consent.
2. Assign a study identification number.
3. Record/complete medical history and demographics.
4. Review inclusion/exclusion criteria.
5. Randomize the patient and handout the decolonization set and the questionnaire.
Visit 2 (End-of-Treatment)
1. Record any additional interventions required.
2. Recuperate the empty packages and the questionnaires (only for decolonized patients).
3. Assess all adverse events of decolonization and related to the trial.
Visit 3 (Test-of-Cure)
Every effort will be made to ensure that the final efficacy assessments (i.e., primary outcome data) are available for all study participants. Outpatients should return to the clinic (assessments can be also performed in the hospital), where the following assessments will be performed:
1. Assess all past adverse events of surgery, hospitalization and of decolonization
2. Record all clinical and microbiological SSIs, its treatment and wound problems (if any).
For The Study Database, We Will Have Assessed The Following Variables:
Patient’s characteristics (age, biological sex, body mass index, renal insufficiency, cirrhosis, other immune-suppressions, diabetes, pregnancy), indication of surgery, presence of osteosynthesis, all postoperative complications, SSI and pathogens, all adverse events during the study period, length of hospital stay, duration of eventual VAC (vacuum-assisted closure) / PICO use [20], and the patient’s opinion on the decolonization set (questionnaire) immediately after surgery. The Table 3 indicates the timepoints of different assessments.
Questionnaire
The previously validated questionnaire will be in German language with a total of seven predefined and open questions regarding the difficulties of decolonization, the completeness of scheduled actions, all adverse events during decolonization and surgery, and two questions regarding the scientific comprehension about the procedure (indication for decolonization, potential benefit expected in the individual case). The Infection Control nurses hands out the questionnaire at enrolment. If the patient has not filled it in until hospitalization, the Infection Control nurses will fill it in together with the patient, bed-side and immediately after surgery.
Follow-up For Bone Surgeries With Implants In Place
Usually, patient with implant-related orthopedic surgery return for a routine surgical control after one year. If this is not the case, the study nurse, or the study investigators might phone the patient for a follow-up information regarding the study outcomes.
Risks Of The Trial For Participants
All patients can witness adverse events related to decolonization products or the surgical procedures. One theoretical risk could be a transient skin irritation, or allergy, to octenidin, which we assess in full detail. Overall, we expect no substantial adverse events according to reports from other centers and colleagues who already use the set for decolonization. Of note, the commercial set is in widespread use since 2016 and freely available on the Swiss market.
Participant timetable
For this trial, we probably need 24 months; starting on February, 27th 2023 (Table 4).
Monitoring and potential Audits
The Unit for Clinical and Applied Research (UCAR) will assign an independent monitor with experience in prospective-randomized trials. The monitor verifies all, or a part of the Case Report Forms (CRF), data and written Informed Consents. According to the Monitoring Plan, the first visit will occur prior to the start, the second during the interim analyses, and the last visit at the study end (Table 5). A quality assurance audit/inspection may be conducted by the competent authority. The auditor/inspectors have access to all medical records, the investigator's study files and correspondence, and the Informed Consent Forms. The Principal Investigator and the Sponsor will allow the persons being responsible for the audit to have access to the source data. All involved parties will keep the patient data strictly confidential.
Study period
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Time
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Monitoring
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Table 5
Before study
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January to February 2023
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Monitoring will be informed about study conduct concerning data sampling and safety reporting.
Monitor controls if
- Documents are approved
- Documents are at site
Investigators are familiar with study protocol and safety reporting
Investigators know their duties and responsibilities
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During Study
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Spring 2024
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All subjects: SDV for existence and informed consent
First trial participant and at least 10% of trial participants recruited at the time of the monitoring visit, as far as available: eligibility, primary endpoint, SAEs
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Study end
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December 2024 to January 2025
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Control for completeness of source data
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Statistical analyses, sample size calculations, and recruitment potential
Main Hypotheses
Among our selected study participants with an elevated risk for SSI and wound revisions, the pre-surgical decolonization may reduce the incidence of unplanned surgical revisions by 5% (from 10% without decolonization to 5% with decolonization).
Determination Of Sample Size
In our hospital, postoperative wound problems occur in at least 5% percent of all orthopedic interventions. However, the incidence for revision surgery in our particular study population is 10%; according to our clinical experience. We perform a superiority RCT with a power of 80% in favor of the decolonization. With 95% event-free surgeries in the decolonization arm versus 90% in the standard arm, we formally need 2 x 474 orthopedic surgery episodes, which we round up to 2 x 500 surgeries (n = 1,000). For the secondary outcomes (adverse events, questionnaires), we have no formal, or minimal, sample sizes required.
Planned Statistical Analyses
First, all analyses will be performed for the entire study population. In a second step, all analyses will be separately performed within substrata of patients, which are based on the type of orthopedic procedures (e.g. arthroplasties, implant-related surgeries) and the patients’ demographic parameters (elderly patients, immune suppression, high ASA-Scores). We will use descriptive statistics and compare groups using the Pearson-χ2-test, the Fischer-exact-test, or the Wilcoxon-ranksum-test, as appropriate. We will also recur to composite (SSI and wound problems) and separated (SSI; wound problems) multivariate analyses using a Cox regression model targeting the primary outcome variables. Variables with a p-value ≤ 0.2 in univariate analysis will be included in a stepwise forward selection process for multivariate analysis. Key variables will be checked for interaction. The number of variables in the final model is limited to the ratio of 1 outcome variable to 5 to 8 events [23]. The significance level is p ≤ 0.05 (two-tailed). We will use STATA™ (Version 15, College Station, Texas, USA).
Interim Analysis And Early Termination
We will perform one interim analysis 1 year (+/- 2 months) after the inclusion of the first patient. If the result of group comparison between the decolonization and non-decolonization arms are statistically significant regarding the study objectives, the independent Data Monitoring committee will decide upon the interruption, or early termination, of the trial. Otherwise, the study continues. This committee will be composed of physicians and nurses with clinical experience in orthopedic infections and related research, who are not part of the Investigators of the BALGDEC trial. The Data Monitoring committee has also the right to call on a premature, additional interim analysis. We might also perform a futility analysis to check if the expected statistical power for the final analysis will not be < 30%. If it is lower than 30%, we will consider the trial will not be able to demonstrate the result, and the recruitment is no more ethical [24]. To balance (at least partially) for a potential power loss, we also may recruit 100 supplementary patients per arm; i.e. 600 episodes in each randomization arm.
Final Analyses
The intent-to-treat (ITT) population will consist of all randomized patients. Patient disposition and baseline characteristics will be based on the ITT population. The per-protocol (PP) population will consist of all patients who complete the study (or who are otherwise defined as a treatment failure) according to the clinical investigation plan and who have not deviated significantly from the protocol. All efficacy analyses will be repeated using the PP population.
Handling Of Missing Data And Drop-outs
Significant missing data regarding the decolonization and outcomes will lead to a patient dropout. Drop-outs will be reported in the *Methods* section and excluded from both, the ITT and the PP populations. However, due to the relatively short intervention period, we do not expect many missing data, and renounce on imputations. The independent Data Monitoring Committee may help in case of difficult interpretations of available data.
Ethical and regulatory aspects
Study Registration
The study is registered in the Swiss Federal Complementary Database (BASEC 2023-00095) and in the international registry ClinicalTrials.gov (Number NCT05647252). Supplementary File 1 is the original study protocol.
Categorization Of This Study, Safety Reports And Eventual Amendments
This study makes use of a decolonization set that is already authorized in Switzerland. The indication and the dosage are used in accordance with the prescribing information. The study protocol will not be changed or amended without prior Ethical Committee’s approval. Premature interruption is reported within 30 days. The regular study end is reported to the Ethical Committee within 90 days, the final study report within one year. The Ethical Committee and authorities will receive annual safety reports. The study will be carried out in accordance with the Declaration of Helsinki, the guidelines of Good Clinical Practice, and the Swiss regulatory authority’s requirements.
Patient Information And Early Termination Of The Study
The investigators will inform potential participants about the study, its voluntary nature, procedures involved, expected duration, potential risks and benefits and any potential discomfort. All participants will be provided an Information Sheet and Informed Consent Form. The original Form stays in the study records. The investigators uphold the principle of the participant's right to privacy and that they shall comply with applicable privacy laws. Subject confidentiality will be further ensured by code numbers corresponding to the computer files. For verification, the Ethics Committee and regulatory authorities may require access to medical records, including the medical history. The Sponsor may terminate the study prematurely in certain circumstances, e.g. ethical concerns, insufficient recruitment, safety issues, alterations in accepted clinical practice making the continuation unwise, or early evidence of benefit or harm of the experimental intervention. All patients are free to withdraw from participation in this study at any time, for any reason, and without prejudice. The withdrawal will not affect the actual medical assistance or future surgical treatments. On rare occasions, the investigators may terminate a patient’s participation to protect his/her best interest. After study termination, the evaluations required at the clinical visits will remain.
Risk/ benefits of the BALGDEC trial
All patients can witness adverse events related to surgical procedures and decolonization. A theoretical risk could be a higher incidence of SSI and related wound problems in the non-decolonization arm. Patients in the decolonization arm could witness more skin irritation, intolerance to octenidin and/or ingredients of the formulations. Their potential benefits are a reduction of SSIs and wound problems in the decolonization arm. Supplementary File 2 is the “Model Consent Form” in English language of the original form in German language.
Safety
All orthopedic surgeries will be performed in the participation of experienced surgeons. The decolonization set is a commercial product in use since 2016. We expect no major adverse events of the product. An annual safety report is submitted once a year to the local Ethics Committee via the Lead Investigator. We, moreover, will perform interim (futility) analyses.
Reporting And Handling Of Pregnancies
The use of topical formulations containing octenidin is not a known danger for the fetus and the breast-fed newborn [7, 8]. However, for purely formality reasons, we will exclude pregnant and/or breastfeeding women. Any pregnancy during the treatment phase of the study and within 30 days after discontinuation of study medication will be reported to the Sponsor-Investigator within 24 hours. The course and out-come of the pregnancy will be followed up carefully, and any abnormal outcome regarding the mother or the child should be reported.
Definition And Assessment Of (Serious) Adverse Events And Other Safety Related Events
An Adverse Event (AE) is any medical occurrence in a study participant, which does not necessarily have a causal relationship with the study procedure. A Serious Adverse Event (SAE) is classified as any untoward medical occurrence that: results in death, is life-threatening, hospitalization or a significant prolongation of hospitalization, persistent or significant disability. The investigators make a causality assessment. All SAEs are reported within 24 hours to the Sponsor-Investigator. SAEs resulting in death are reported to the Ethics Committee within seven days. The Sponsor-Investigator reports the safety signals within seven days to the local Ethics Committee. Patients with AE and leaving the study, will be treated off-study, without restriction, at the study site.
Follow Up Of (Serious) Adverse Events
Participants terminating the study (either regularly or prematurely) with reported ongoing SAE, or any ongoing AEs of laboratory values or of vital signs being beyond the alert limit, will return for a follow-up investigation. This visit will take place up to 30 days after terminating the treatment period. Follow-up information on the outcome will be recorded on the respective AE page in the Case Report Forms. Source data have to be available upon request. In case of participants are lost to follow-up, efforts will be made and documented to contact the participant to encourage him/her to continue study participation as scheduled. In case of minor AE, a telephone call to the participants is acceptable. All new SAE or pregnancies that the investigators will be notified of within 30 days after discontinuation of investigational product will be reported in appropriate report forms.
Data Handling And Record Keeping / Archiving
Data is only saved, and stored, using the secured software REDCap®. Data can only be accessed by defined investigators. An electronic Case Report Form is generated for every study participant. All data will be recorded by study nurses of the UCAR. The ID numbers are assigned by the REDCap® system. Corrections can only be made by authorized persons.
Analysis And Archiving
For data analysis, subject-related data from REDCap® will be exported and analyzed in a statistic software (STATA™). All health-related data will be archived in the REDCap®. Before data export, all patient identifiers are removed. All data will be stored for a minimum of 10 years. Collection, disclosure, storage of data is carried out in accordance with Swiss data protection regulations and the Human Research Act.