Using standardized measurement tools has been regarded is an indication of proper physiotherapy practice (Stokes, 2009). In fact, the use of standardized outcome measures is recommended as a way of promoting evidence- based practice and is part of good clinical practice (Smith, Watson & Connell, 2013). While measurements tools are used in assessments in physiotherapy they are not just limited to assessment. Some of these tools are used to measure other aspects of practice. Verheyaden & Tyson, (2018) states that outcome measurements is just one contribution that measurement tools can make to clinical practice and there are other ways that these tools can be used.
What are standardized outcome measures?
Let’s say you are helping a stroke patient improve the range of motion of his shoulder, so you design an intervention plan. However, one thing is still left, how are you to gauge that you are making some progress? Maybe through goniometry, right? In this case goniometry is the outcome measure. You will use the measurements, before and after the treatment to determine progress. Simply speaking, the outcome measure will help you compare before and after treatment.
As the overarching goal is to improve functioning, outcome measures should capture recovery and restoration, and the results of the interventions we use (Lexell & Brogardh, 2014). The benefits of using outcome measures include; providing a common language to define patients’ problems, and for proper communication between the multidisciplinary team. Helping promote person centered care and helping in decision making and treatment planning.
The ICF and outcome measures.
The problems that neurological therapy aims to treat are covered within the ICF and can be used as a basis to understand the patients’ difficulties and identify appropriate measurement tools. Outcome measures often focus on impairments (as defined in the ICF) and can be both objective (i.e. performed by staff) and self-report (i.e., based on the patient’s subjective perception)(Lexell & Brogardh, 2014).
Factors to consider when choosing an outcome measure.
The purpose of the measure.
To properly understand your purpose of your measure you should understand:
- Why do you want to evaluate practice?
- What specifically can be measured to meet your purpose?
- What type of information will you collect?
- When will the information be collected?
- What decisions might be made using the information collected?
You can use the ICF framework to guide you on what you are aiming to measure. Components of the framework such as impairments, activity limitations and participation restrictions can be very good guides.
Clinical utility of a measure
To be useful within the clinical setting the measure should be simple, easy to use. It should also be cost effective as some of the measurement tools might require payment before use.
Scientific properties of a measure
The measure should possess these scientific properties:
Reliability refers to the stability of the scores obtained when a tool is used to take a measurement more than once. Basically, how reliable will the tool be if it’s used by another therapist, interrater reliability, or if used by the same therapist, intrarater reliability, to assess the same patient/s.
The question being:
- Do I know the rate of error detected with scores?
The term validity refers to consideration of whether (or to what extent) a measurement tool measures the construct (or issue/ idea) it intends to measure. This is sometimes described as ‘Does it do what it says on the label?
The question being:
- Does it measure what I want it to measure?
Important aspects while assessing validity.
Sensitivity is the ability of a tool to correctly predict whether a diagnosis, outcome or event is present (i.e. the number of true positives).
Specificity is the ability of a tool to correctly predict whether a diagnosis, outcome or event is not present.
Positive predictive value
Positive predictive value is the proportion of evaluated subjects with a positive test result and who have the disease, outcome or event (i.e. the proportion of true positives).
Negative predictive value
Negative predictive value is the proportion of evaluated subjects with a negative test result and who do not have the disease, outcome or event (i.e. the proportion of true negatives)
Responsiveness is the ability to measure clinically meaningful or important change. The question being:
- what is the minimum meaningful clinical change can it detect?
Standardization procedures provide clear, explicit instructions on how to undertake every part of the measure. It is advantageous to choose a measure that is widely known (for example the Medical Research Council muscle strength grading system)
5. Other factors to consider are:
- The time it takes to complete the measure
- Difficulty in using the measure
- Resources or specialized tools/experience needed to carry out the measure.
|Ataxia/Coordination||Scale for the assessment and rating of ataxia (SARA)|
Finger nose test Gagnon et al (2004)
|Muscle tone impairments/ spasticity||Modified ashworth scale (validity and responsiveness limited (Verheyden & Tyson, 2018)) |
Arm Activity Measure
Leg Activity Measure
|Fatigue||Fatigue severity scale|
Neurological Fatigue Index (NFI) for multiple sclerosis, Mills et al 2010)
|Muscle weakness||Motricity Index (Wade 1992)|
|Sensation impairments||Rivermead Assessment of Somatosensory Perception (RASP),Tyson and Busse (2009)|
|Shoulder subluxation||manual palpation|
|Walking||Six-Minute (or Two-Minute) Walk Test.|
5-m or 10-m walk test
|Falls||Forward Reach and Arm Raise Tests (in sitting & standing)|
Timed Up and Go
|Upper limb function (grip)||Nine Hole Peg Test|
Fawcett, A. J. L. (n.d.). Principles of Assessment and Outcome Measurement for Occupational Therapists and physiotherapists.
Gagnon, C., Mathieu, J., Desrosiers, J., 2004. Standardized finger-nose test validity for coordination assessment in an ataxic disorder. Can. J. Neuro. Sci. 31 (4), 484–489
Lexell, J., & Brogardh, C. (2014). The use of ICF in the neurorehabilitation process The use of ICF in the neurorehabilitation process. https://doi.org/10.3233/NRE-141184
Mills, R.J., Young, C.A., Pallant, J.F., et al., 2010. Development of a patient reported outcome measure scale for fatigue in multiple sclerosis: The Neurological Fatigue Index (NFI?MS). Health Qual. Life. Outcomes. 8, 22.
Smith, C., Watson, A., & Connell, L. (2013). Neurological physiotherapy. In Tidy’s Physiotherapy (15 th).
Stokes, E. K. (2009). Outcome measurement. In Pocketbook of Neurological Physiotherapy (pp. 191–201). https://doi.org/10.1016/C2009-0-37172-X
Stokes, E. K. (2010). Rehabilitation Outcome Measures. https://doi.org/10.1016/B978-0-443-06915-4.00001-2
Tyson, S., Busse, M., 2009. How many body locations need to be tested when assessing sensation after stroke? An investigation of redundancy in the Rivermead Assessment of Somato sensory Perception. Clin. Rehabil. 23, 91–95
Tyson, S., Watson, A., Moss, S., Troop, H., Dean-lofthouse, G., Jorritsma, S., & Shannon, M. (2008). Development of a framework for the evidence-based choice of outcome measures in neurological physiotherapy. 30(2), 142–149. https://doi.org/10.1080/09638280701216847
Verheyden, G., & Tyson, S. F. (2018). Measurement Tools. In Physical Management for Neurological Conditions (pp. 77–88).
Wade, D.T., 1992. Measurement in Neurological Rehabilitation. Oxford University Press, Oxford.
Yoward, L. S., Doherty, P., & Boyes, C. (2008). A survey of outcome measurement of balance , walking and gait amongst physiotherapists working in neurology in the UK. 94, 125–132. https://doi.org/10.1016/j.physio.2007.08.005