PREP2 Basic: SAFE score

 

The SAFE score is calculated by scoring Shoulder Abduction and Finger Extension of the paretic upper limb using the Medical Research Council grades.

The patient’s strength in each of these movements is scored between 0 and 5. You can use the grades below. Avoid using + and – signs to keep things simple.

0 = no palpable muscle activity
1 = palpable muscle activity, but no movement
2 = limited active range of motion without gravity
3 = full active range of motion against gravity, but no resistance
4 = full active range of motion against gravity and resistance, but weaker than the   other side
5 = normal power

Each movement is graded separately, and then the two scores are added to calculate the SAFE score out of 10.

For patients with inattention or fatigue, effort needs to be made to ensure the patient is focused on the arm to give the most accurate indication of strength.[

Shoulder abduction should be tested with resistance applied proximal to the elbow and taken through a full range of motion.

If shoulder range of motion is limited by a pre-existing musculoskeletal condition, evaluate power within the patient’s pain-free passive range of motion.

 

 

Finger extension should be tested with the wrist stabilised, resistance applied distal to metacarpal phalangeal (MCP) joints and taken through a full range of motion.

If the fingers have unequal strength, use a majority rule: If three fingers have the same score, use this score; if two fingers have a lower score than the other two fingers, use the lower score.

 

 

If the patient has a SAFE score of 5 or more on Day 3 after stroke, you can use the PREP2 prediction tool to make either an Excellent or Good prediction, depending on their age.

 

FAQs

Who can obtain the SAFE score?
Physiotherapists, occupational therapists, or those with qualifications in neuromuscular assessment can obtain the SAFE score. It is most likely that those working in the acute stroke setting will perform SAFE testing, though other staff that provide cover to this area or a weekend therapy service may be required to obtain scores. It is recommended that those performing SAFE testing receive training so that testing is standardised.

When should the SAFE score be obtained?
We count the day of the stroke as Day 0, the next day as Day 1, and so on. It’s important to get the SAFE score each day until you are able to give a prediction, or you get to Day 3, whichever occurs first.

If someone is found to have had a stroke and was last seen well the previous day or a few days ago, which day is taken as Day 0 for obtaining SAFE scores?
If the patient is unable to remember when the stroke symptoms started, then as a general rule Day 0 is taken as the date when the patient was found rather than when they were last seen well. This can depend on how long it has been since the patient was last seen well.

For example, consider a patient who lives alone and can’t recall when their symptoms started. Their brother spoke with them on the phone three days ago, and says they sounded fine. The brother then visited the patient at home this morning and found them with stroke symptoms. In this situation, today is Day 0, as they were found by their brother this morning.

Which day is taken as Day 0 if a patient has a wake-up stroke?
For PREP2, stroke onset is considered differently to how clinical teams may consider stroke onset for the purposes of giving thrombolysis or clot retrieval interventions. If someone has developed new stroke symptoms on waking, then the date they wake up is taken as day 0 rather than the previous day when they went to sleep. However, this can depend on when the patient went to sleep and when they wake up. For example, if someone goes to sleep at 8pm and wakes up at 1am the next day with symptoms the date of stroke is likely the date they went to sleep.

What if the fingers have unequal strength?
Use a majority rule. If three fingers have the same score, use this score. If two fingers have a lower score than the other two fingers, use the lower score.

What do you do if the patient’s overall strength is weaker than ‘normal’ and I would score them 4/5 on the non-affected side?
Score the affected arm relative to the non-affected arm. If the movement on the affected arm is weaker than the non-affected arm (but still has full range of movement against gravity and some resistance) score it as 4/5. If they can only move against gravity and not resistance, then they would score a 3/5. Discussing with a colleague or obtaining a second opinion is useful any time a SAFE score isn’t clear. Make your scoring rationale clear in any documentation.

What grade do you give if a patient has some movement against gravity but can’t achieve a full active range of motion due to weakness from the stroke?
Score the affected movement as 2/5. For a score of 3/5 the patient needs to be able to achieve full range of motion against gravity.

How should you record a SAFE score when a patient has pre-existing pain, orthopaedic or musculoskeletal issues?
If the patient has a pre-existing biomechanical restriction or pain, you will need to perform a more thorough assessment to determine any influences from pain, passive joint restrictions or previous strength deficit that influences your current SAFE score. Discussing with a colleague or obtaining a second opinion is useful any time a SAFE score isn’t clear. Make sure your scoring rationale is clear in the documentation.

For example, consider a patient who has bilateral osteoarthritis of the shoulders. In their words, prior to their stroke they were able to move both arms to about half-way and then it was too stiff and sore to go further. When scoring shoulder abduction review their pain-free passive range of shoulder abduction motion first and assess their MRC relative to this. For example, if they had a passive range of motion of 90 degrees but active range of motion of 45 degrees with gravity eliminated, they would score 2/5. Whereas if they had active movement through their full available range of motion (90 degrees) against gravity but not resistance they would score 3/5. When sharing their prediction their predicted upper limb outcome would need to be considered in context with their pre-existing condition i.e. an excellent recovery would likely be a return to their pre-existing level of hand and arm function.

If you know the prediction at Day 1 is Excellent should you deliver it then, or wait until Day 3?
Receiving an early Excellent prediction may be suitable for most patients, and even helpful to their rehabilitation. It may be particularly useful if a patient is likely to be discharged before Day 3. However, it is worthwhile considering any factors that may alter their prediction. If they are medically unstable, or if there is a considerable risk of further stroke or haemorrhagic transformation it might be better to wait until Day 3. A new stroke or progression of stroke symptoms which results in worsening upper limb weakness means that the PREP2 prediction tool should be started again.

What do you do if a patient has a Day 2 SAFE = 4 and then is discharged to another facility?
Contact the therapist at the new facility and provide a handover of PREP2, and the information collected to date. Ideally have the therapist do a SAFE score on Day 3. They might to be given instructions on how to do this, and you can refer them to www.presto.auckland.ac.nz for more information.

• If the SAFE score on Day 3 is at least 5, and the patient is less than 80 years old, then they can be given verbal and written information for an Excellent prediction.
• If the SAFE score on Day 3 is at least 5, and the patient is 80 years or more, then they need a SAFE score of at least 8 to be given an Excellent prediction. Otherwise, they can be given a Good prediction.
• If the SAFE score on Day 3 is less than 5, they require TMS to obtain an upper limb prediction so PREP2 may need to be discontinued at this stage if the facility is not trained in TMS for PREP2

What if Day 3 falls on the weekend, but there is no weekend therapy service to obtain the SAFE score?
If a Day 3 SAFE score is due on Saturday, then obtain the score on Friday. If a Day 3 SAFE score is due on Sunday, then obtain the SAFE score on Monday.

How many people can get a PREP2 prediction with the SAFE score alone?
The SAFE score and age can give an upper limb prediction for around two thirds of patients.

 

Case Examples
Here are some case examples illustrating how the SAFE score can be used to predict upper limb functional outcomes.

Mrs Peters (74 y)

Day 0 (day of symptom onset): Unable to get a SAFE score, as she was admitted late that night and no staff were available.
Day 1 (day after symptom onset): SAFE = 2
Day 2: SAFE = 4
Day 3: SAFE = 5. Now we can give her an Excellent prediction, as she has achieved a 5 on Day 3, just in time, and is less than 80 years old.

 

Mx Jackson (87 y)

Day 0 (day of symptom onset): SAFE = 6
Day 1 (day after symptom onset): SAFE = 8, so we can give then an Excellent prediction right now, even though it’s only Day 1. This is assuming they don’t deteriorate over the next couple of days, in which case we’d have to re-assess then. But assuming they’re stable, we expect them to remain at 8 or above, so they are most likely to have an Excellent functional outcome for their upper limb.

 

Mr Lee (63 y)

Day 0 (day of symptom onset): Unable to get a SAFE score, it was a Sunday and no staff were available.
Day 1 (day after symptom onset): SAFE = 2
Day 2: SAFE = 3
Day 3: SAFE = 4, so we can’t give him an Excellent prediction, and we remain unsure of his prediction if we don’t have TMS available. All we know for sure is that he’s not in the excellent category.

If TMS was available we would obtain his NIHSS score on Day 3, then wait to find out whether he was MEP+ or MEP- to determine if was ‘Good’ (if MEP+), ‘Limited‘ (if MEP- and NIHSS < 7), or ‘Poor’ (if MEP- and NIHSS ≥ 7)

Quiz

Click here for a quiz to assess your learning on the SAFE score.

Once the practice quiz has been completed with at least 70% correct you will be emailed a link to the final quiz for this section.

If you pass the final quiz with at least 80% correct you will be emailed a certificate of completion for the SAFE score section. There is no limit to the number of attempts for the practice or final quiz.