This study will investigate the effect of simulation-based training with mastery learning (SBML) on novice performers' lumbar puncture (LP) performance in a clinical setting. The study will investigate the effect on operators' performance, stress level, and on patient experienced stress, confidence in operator, and patient-related outcomes of pain, and risk of subsequent Post Dural Puncture Headache (PDPH), and days of sickness leave.

The study will compare the effect of the training to a control group of novices receiving standard training and additionally to an intermediate and an expert group.

The study will provide insight into the translational effect from the simulation based setting to clinical performance. Further, the study will explore: if stress decreases operators' performance; if operators stress affects the patient stress level; and the effect of SBML on patient-related outcomes.

The lumbar puncture procedure is considered a complex procedure. Junior doctors hold uncertainties in performing the procedure and perform below stakeholders expectations. This conflicts with the potential need for immediate performance on critical patients.

The traditional training for junior physicians has been guided by the expectation that experience will lead to mastery. This assumption has been disproved by simulation based and observational studies calling for more educational research including its impact on patient outcomes. A contrast to the maxim of "see one, do one, teach one" is mastery learning (ML). ML implies that learners should practice and re-test until they reach a designated mastery level, making the final level the same for all, although the time taken to reach that level may vary.

Novices trained by simulation based training with mastery learning (SBML) achieve a higher performance level than more experienced physicians only having received clinical training. However, the translational effect into the clinical context is unknown as the training and assessment of competence was performed in the simulation based setting, not integrating aspects as patient communication and positioning. For the lumbar puncture, the complexity of the procedure pertains to both technical and non-technical aspects as patient interaction, communication, the corporation with the assistant and environmental conditions.

Hence, there is a need for more knowledge on the effect of simulation-based training with mastery learning for junior doctors' performance in the clinical setting which should include the effect on patient-related outcomes.

As novices describe a fear of doing harm and hold performance related uncertainty, they may be susceptible to experience a stress sensation. Stress during performance of clinical procedures reduces the working memory and is associated with impaired performance. Expert performers' reports that stress during the procedure performance might be transmitted to the patient. Patients experiencing stress during the procedure holds a significantly increased risk of a prolonged duration of post dural puncture headache.

Stress- stimuli, experience, and responses are complex, as the judgment on whether a situation is perceived as pleasant or threatening depends on the individuals' appraisal, which is based: on previous experience; previous learning; the setting and expectations of the outcome. Stress stimuli arise when the appreciation of the situation is negative. Performers holding a strategy for their performance during stress are less prone to experience a stress sensation. Hence, the integration of a strategy for performing the procedure, based on the experts' process goals might benefit novices' risk of experiencing stress during procedure performance. The effect on such stress reduction to the patient experience of stress and the risks of procedure-related side effects has never been investigated.

The aim of this study is to investigate the effect of simulation-based training with mastery learning on novices' lumbar puncture performance, patient related outcomes and stress experienced by the physicians and patients during the procedure. The effect and outcomes will be compared with intermediate and expert lumbar puncture performers.

For the medical doctors randomized:

Inclusion Criteria:

• MD, or Medical student working as substitute junior medical officer, or having clinical rotation at the study sites.
• Speaking Danish fluently

Exclusion Criteria:

• Previous Lumbar Puncture experience
• Previous formal training in the lumbar puncture procedure

Eligible patients:

Inclusion criteria:

• Glasgow Coma Scale 15
• Referred to the outpatient clinic for a lumbar puncture.
• Proficiency in the Danish Language
• Age between 18 and 80 years
• Understand study implications and co-operate without a need for personal assistance.
• Providing written and orally informed consent

Exclusion criteria for patients:

• Lumbar puncture intended on suspicion of Alzheimer or other dementia diagnosis.
• Cognitive impairment, assessed by the study investigator or local nurse/doctor
• Physical disabilities, requiring personal assistance.