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OrthoMeasure

Patient-reported outcome measure

WOSI Calculator

Western Ontario Shoulder Instability Index

The Western Ontario Shoulder Instability Index is a 21-item patient-reported measure of the quality-of-life effects of shoulder instability, each item rated 0 to 100 across four domains — physical symptoms, sports and work, lifestyle and emotions — and usually reported as a percentage of normal in which 100% means no impairment.

Licence unconfirmed21 items~8 min0–100, higher is better

Physical symptoms

The following questions concern the symptoms you have experienced due to your shoulder problem. In all cases, please enter the amount of the symptom you have experienced in the last week, from 0 to 100.

0 = no pain, 100 = extreme pain.

of 100

0 = no aching/throbbing, 100 = extreme aching/throbbing.

of 100

0 = no weakness, 100 = extreme weakness.

of 100

0 = no fatigue, 100 = extreme fatigue.

of 100

0 = no clicking, 100 = extreme clicking.

of 100

0 = no stiffness, 100 = extreme stiffness.

of 100

0 = no discomfort, 100 = extreme discomfort.

of 100

0 = no instability, 100 = extreme instability.

of 100

0 = not at all, 100 = extreme.

of 100

0 = no loss, 100 = extreme loss.

of 100

Sports, recreation and work

0 = not limited, 100 = extremely limited.

of 100

0 = not affected, 100 = extremely affected. If your shoulder affects both sports and work, consider the area that is most affected.

of 100

0 = not at all, 100 = extreme.

of 100

0 = no difficulty, 100 = extreme difficulty.

of 100

Lifestyle

0 = no fear, 100 = extreme fear.

of 100

0 = no difficulty, 100 = extreme difficulty.

of 100

0 = no difficulty, 100 = extreme difficulty.

of 100

0 = no difficulty, 100 = extreme difficulty.

of 100

Emotions

0 = not conscious, 100 = extremely conscious.

of 100

0 = no concern, 100 = extremely concerned.

of 100

0 = no frustration, 100 = extremely frustrated.

of 100

What the WOSI score means

WOSI totals run from 0 to 100, where a higher score is better. No severity bands are shown because no cut-offs have been published that we can verify — read the total against the source studies and your own protocol, as described below.

    How the score is calculated

    Stated in full so the calculation can be independently checked, and reproduced by hand if needed.

    Each of the 21 items is rated by marking a 100 mm line from no symptom (0) to the extreme (100), so each item contributes 0 to 100 and the raw total runs from 0 to 2100, where 0 is no impairment. The items fall into four domains: physical symptoms (items 1 to 10, out of 1000), sports, recreation and work (items 11 to 14, out of 400), lifestyle (items 15 to 18, out of 400) and emotions (items 19 to 21, out of 300). Each score is converted to a percentage of normal as (maximum − raw score) ÷ maximum × 100, so 100% is no impairment and a higher percentage is better. An 11-point numerical scale of 0 to 10 is also used, in which case the raw total runs to 210. The raw total and the percentage run in opposite directions, so state which is being reported.

    Missing data

    No missing-data rule has been published, so a total is shown only when all 21 items are answered. A domain score is shown as soon as every item in that domain is answered.

    Instrument profile

    Developer
    Alexandra Kirkley, Sharon Griffin, Heidi McLintock and Linda Ng
    Institution
    University of Western Ontario, Canada
    First published
    1998
    Custodian
    No custodian known to us; the form is distributed by the American Academy of Orthopaedic Surgeons among its preferred measures
    Items
    21
    Response format
    Visual analogue scale, 0 to 100 per item
    Score range
    0 to 100
    Direction
    Higher score = better
    Recall period
    The last week
    Completion time
    About 8 minutes
    Age range
    Adults
    Regions
    Shoulder
    Conditions
    Shoulder instability, Recurrent anterior shoulder dislocation, Glenohumeral instability
    Procedures
    Arthroscopic Bankart repair, Open Bankart repair, Latarjet procedure, Shoulder stabilisation
    Languages
    English
    Test–retest (ICC)
    High in later reviews; not reproduced here for the same reason.
    Internal consistency
    High in later reviews of the index; the figures are not reproduced here because we have not checked them against the primary studies.
    Validity
    Developed to measure the quality-of-life consequences of shoulder instability specifically, as distinct from general shoulder function, with items on fear, protection of the arm and the effect on sport.
    Responsiveness
    Widely used to report results of instability surgery. No minimal clinically important difference is shown here because we could not verify a published value.

    When to use the WOSI

    Well suited to

    • Patients with recurrent shoulder instability, before and after stabilisation surgery, where the question is the effect on quality of life rather than recurrence alone.
    • Reading the instability literature, where the WOSI is the most commonly reported disease-specific measure.

    Limitations and poor fits

    • Shoulder problems that are not instability — use the SPADI, ASES or Constant score.
    • Recording whether the shoulder has redislocated and how it moves: the Rowe score weights those directly.
    • Comparing totals across studies without checking whether the raw total or the percentage of normal was reported, since they run in opposite directions.

    WOSI compared with other instruments

    Instruments measuring a related construct, with the practical difference between them.

    InstrumentItemsRangeWhat it adds
    Rowe Score30–100The Rowe score is a 100-point clinician-administered rating for shoulder instability that awards 50 points for stability, 20 for range of motion and 30 for function, where 100 represents a stable, fully mobile and unrestricted shoulder.
    SPADI130–100The SPADI is a 13-item patient-reported questionnaire that measures shoulder pain and disability over the past week on two subscales — 5 pain items and 8 disability items — each rated 0–10 and transformed to a 0–100% score in which a higher score means more pain and greater disability.
    ASES Score110–100The ASES score is a patient-reported shoulder index running from 0 to 100 in which a single 0–10 pain rating supplies 50 points and ten activities of daily living rated 0–3 supply the other 50, so that 100 represents a pain-free shoulder with no functional difficulty.
    SST120–12The Simple Shoulder Test asks twelve yes-or-no questions about everyday shoulder functions and scores the number answered yes, giving a total from 0 to 12 where 12 means all twelve functions are retained.
    Oxford Shoulder Score120–48The Oxford Shoulder Score is a 12-item patient-reported questionnaire about shoulder pain and everyday function over the past four weeks, each item scored 0 to 4 and summed to a total of 0 to 48 in which 48 represents the best possible shoulder — it is licensed by Oxford University Innovation, so the item wording is not reproduced here.

    Copyright and permitted use

    Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.

    Licence unconfirmed

    The index is distributed on the American Academy of Orthopaedic Surgeons’ outcome-measures site and used throughout the instability literature. We have not asked the developers for written permission, so we cannot say it is free of copyright for every use; if a rights holder objects, the item wording will be removed and the page reduced to a profile.

    References

    1. Kirkley A, Griffin S, McLintock H, Ng L. The development and evaluation of a disease-specific quality of life measurement tool for shoulder instability: the Western Ontario Shoulder Instability Index (WOSI). American Journal of Sports Medicine. 1998.

    Editorial status

    Not yet reviewedQueued for clinical review by Sam Tuffun, PT, DPT. Sign-off has not taken place — this is a placeholder assignment, not a completed review.