The aim is to evaluate the study design, procedure and measurements in a randomised controlled pilot study.

Despite that mild traumatic brain injury (mTBI) is a common condition managed in various healthcare settings, early team based neurorehabilitation (TbNR) in post-concussion syndrom (PCS) is sparely investigated. Therefore we aim to design a high quality randomised controlled study (RCT) investigating the effect of early TbNR in PCS. Prior this RCT a pilot study will be conducted with the aim to evaluate the study design, procedure and measurements.

Method:

Thirty consecutive patients visiting Alingsås hospital emergency department due to head injury caused by fall, trauma to the head, traffic accident or abuse, and diagnosed with brain concussion (ICD10 S060, S0600) for the first time or after repeated trauma, will be asked to participate in the study. The patient will receive a written study information when discharged, and asked if an occupational therapist can contact the patient by phone for further information and screening questions 14 days after trauma. If the patient meet the inclusion criteria and wish to participate in the study a written informed consent will be obtained.

Test procedure:

A structured interview and the assessment described below will be performed at baseline 3-4 weeks after the trauma and after 16 weeks by an occupational therapist. Participant's characteristics such as age, gender, work ability, education, social status, previous trauma to the head and known comorbidity are collected. The classification of the mTBI will be collected from the patients' medical journal, as well as the result and time of the CT examination if it has been performed. Information about previous sick leave will be collected from the Swedish health insurance office. The number of visits to the occupational therapist (OT) and the physiotherapist (PT) will be recorded from the participant's medical journal.

Study protocol In this pilot study we plan to evaluate broadly as the persons with mTBI may suffer from a complex symptomatology, and the causes of persisting symptoms are unclear.

The following data will be collected:

• The number of patients who meet the inclusion criteria.
• The number of patients consenting participation in the study.
• The number of patients completing questionnaires at baseline and post-test.
• The number of patients who participate in the intervention.

Randomisation:

After screening for eligibility, fulfilling inclusion criteria and consenting to participation the baseline assessment will be conducted by an OT at enrolment. After this the patients will be randomised either to the intervention or control group in using lots in sealed envelopes based on a computer generated group allocation. The lots are kept in sealed envelopes prepared by a person not involved in the study. An OT will open the envelope and inform the patient about group allocation. All care providers will be blinded for baseline and post-test outcomes. A research co-worker who are involved in data management will be blinded for group allocation.

Interventions:

The patients randomised to the intervention group (n=15) will be treated by the PT and OT in TbNR. At the first visits a medical history will be taken, there after a structured interview will be made by the OT about activity level, and an examination of the patients bodily and neurological symptoms will be made by the PT. Based on this result a TbNR a rehabilitation plan is established consisting of the patient's goals, and the purpose that the patient shall be as active as possible without triggering symptoms. An individual exercise program is prescribed. Number of visits to TbNR will depend on the individual need for rehabilitation.

Between each appointment with TbNR, the patient will have personal tasks to accomplish with the purpose of being active based on symptoms and the adaptation to the current level of energy. Information about underlying causes of perceived symptoms will be present at the visits, and the patient will be given help to analyze the tasks that has been performed during the past week. The perceived symptoms will be logged in an activity log including estimation of fatigue and headache. A week-schedule will be created in the purpose of helping the patient to a balanced activity level in relation to their current capacity.

The PT assesses physical activity level and reactions to physical strain. Adaptations are made to the exercise program and advice is given on physical activity and exercises. When appropriate the OT advices about returning to work and adaptations concerning work.

Control:

Participants will be treated as usual, which is that they can search health care by themself.

Statistics:

Ratio and interval data are presented as mean ± 1 standard deviation (SD), ordinal data are presented as median, and 25th and 75th percentile, nominal data are presented in absolute and relative numbers.

Change between baseline and post-test will be analyzed for each outcome measure and between the groups. Depending if the data are normal distributed or not parametric or non-parametric tests will be used for differences between group.

Effect sizes and 95% confidence intervals will be calculated. Cohen's d will be used to estimate the effect size using mean difference between groups and pooled standard deviation of the mean differences. The magnitude of effect size will be considered small for d = 0.2 - 0.49, medium for d = 0.5-0.79, and large for d = 0.8-1.1 (16).

Odds ratio will be used to estimate effect size for binary dependent variable using logistic regression. Linear regression analysis will be used for change of outcome measurements adjusting for gender, number of head trauma and if the injury has been caused by another person or not. The Statistical Package for Social Science (SPSS) for Windows, Version 22.0, 2013. IBM Corp, Armonk, NY: USA will be used for statistical analyses. A p-value < 0.05 is considered statistical significant.

Sample size:

In the planned pilot study 30 participants will be enrolled. This sample size is considered to be sufficient to analyze effect size for the included outcome measurements which will be used for planning the full-scale randomized controlled study involving more emergency hospitals and neuro teams.

Inclusion criteria:

• Head injury for the first time or repeated trauma.
• Diagnosed with brain concussion (ICD10 S060, S0600) by a physician.
• Persistent symptoms after mTBI or decreased activity level at time for inclusion.

Exclusions criteria:

• No remaining symptoms after mTBI at time for inclusion.
• Returned to previous activity daily living level as before trauma.
• Other serious illness.
• Unwillingness to participate in the study.

After screening for eligibility, fulfilling inclusion criteria and consenting to participation the baseline assessment will be conducted by an OT at enrolment. After this the patients will be randomised either to the intervention or control group in using lots in sealed envelopes based on a computer generated group allocation. The lots are kept in sealed envelopes prepared by a person not involved in the study. An OT will open the envelope and inform the patient about group allocation. All care providers will be blinded for baseline and post-test outcomes. A research co-worker who are involved in data management will be blinded for group allocation.