Patient Specific Functional Scale

Clinical intent

Patient Specific Functional Scale was developed by Stratford et al 1995 as a self-report outcome measure of function that could be used in patients with varying levels of independence [1]. The aim of PSFS is to provide clinicians with a valid, reliable, responsive and efficient outcome measure that would be easy to use and applicable to a large number of clinical presentations [2].

Method of use

1. Patients are asked to identify up to five important activities they are unable to perform or are having difficulty with as a result of their problem eg putting socks on, shopping.
2. Patients are asked to rate (on an 11-point scale, [0,10]) the current level of difficulty associated with each activity.
3. "0" represents “unable to perform” and "10" represents “able to perform at prior level”
4. Patients select a value that best describes their current level of ability on each activity assessed.

Calculation

The calculation will return the following:

1. Sum of all the activity scores
2. Number of activities that were indicated by the patient
3. Total score where the sum of the activity scores is divided by the number of activities

Clinical interpretation

A lower score indicates problems performing the activities.

References

[1] Stratford P, Gill C, Westaway M, Binkley J. Assessing disability and change on individual patients: a report of a patient specific measure. Physiotherapy canada. 1995 Oct;47(4):258-63.
[2] Horn KK, Jennings S, Richardson G, Van Vliet D, Hefford C, Abbott JH. The patient-specific functional scale: psychometrics, clinimetrics, and application as a clinical outcome measure. journal of orthopaedic & sports physical therapy. 2012 Jan;42(1):30-D17.