Western Ontario Rotator Cuff (WORC) Index

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Top Contributors - Amanda Ager, Kim Jackson and Nikhil Benhur Abburi  

Objective

Shoulder pain remains one of the main reasons to consult a physician or physiotherapist today, with up to one-quarter of the Western population reporting a shoulder problem at any one time.¹ Among shoulder disorders, a rotator cuff (RC) tendinopathy remains the leading source of shoulder pain.^2-5 The Western Ontario Rotator Cuff (WORC) Index is a questionnaire that was purposely developed to help understand the particular signs, symptoms, and functional limitations associated with an RC tendinopathy.

It is an Outcome Measure used by clinicians to evaluate the condition of individuals affected by this pathology. It can help establish goals, prognostic indicators, and an overall rehabilitation plan for individuals affected by an RC tendinopathy. 

Intended Population

the WORC Index, is a disease-specific quality of life questionnaire, evaluating the change in symptoms specific to a RC tendinopathy.

This questionnaire has been used with individuals with a clinical diagnosis of an impingement syndrome, RC tendinopathy as well as arthroscopic RC repairs. 

Method of Use

The WORC Index is a self-administering health questionnaire.

It has 21 items, exploring 5 different domains:

(1) Physical symptoms

(2) Sports and recreation

(3) Work

(4) Social function

(5) Emotions

Each question uses a visual analogue scale (VAS) - which is a straight line, representing a 100-point scale, ranging from 0-100.

The maximum score is 2100 (worst possible symptoms). Zero (0) represents no symptoms at all.

To make the final score more clinically friendly, some minor math is involved.  The score can be reported as a percentage by subtracting the total from 2100, dividing by 2100, and multiplying by 100. This will give you an overall percentage. Total final WORC scores can, therefore, range from 0% ( lowest functional status level) to 100% (the highest functional status).⁶

Difficulty of administration: Easy.

Clarity: Very clear directions.

Scoring: Using the VAS, measure the distance from left to right, along the line. The total score is out of 100 (record the value to the nearest 0.5mm).

Final Score - 2100 (max) / 21, x 100%.

For example: A score of 1625.

(1625/2100)/21 = 22.6% (therefore, overall low functional status).

Reliability / Validity / Responsiveness

Reliability

Validity

The WORC Index is highly reliable and supports an Intra-class correlation coefficient (ICC) of 0.96.⁷

Responsiveness can best be understood as the ability of an instrument to detect clinically important changes.⁸

The WORC Index sports a Minimally Clinically Important Difference (MCID) of 245 points of the total score,⁹ or 11.7% (11.7 points on the scaled index with maximum value of 100).¹⁰ This is the amount of change in the results of the final score of the questionnaire, that can be said to be clinically important (an important change for the patient).

An interested study by Wessel and colleagues (2018) found that patients undergoing a RC repair need to improve more than 35 points to see a clinically important change. The WORC Index has a high responsiveness in patients undergoing rotator cuff repair and patients with disease of the rotator cuff without rotator cuff tears.¹¹

Miscellaneous

The WORC is used in research¹² and has already been translated into Canadian French,⁷  German,¹³ Iranian,¹⁴ Norwegian,¹⁵  Portuguese¹⁶ and Turkish¹⁷. Because of it's language versatility, it is a good tool to use for international studies and comparisons.

For more information on the subject, you can look into the Western Ontario Shoulder Tools (WORC, WOOS, WOSI)!¹⁸

Did you know that a Short Form version (7-times) of the WORC Index (Short-WORC) is up and coming? For more information, please read:

https://experts.mcmaster.ca/display/publication180754

Where did it all begin? Western University, in London, ON Canada. Check it out!

http://www.uwo.ca

Links

Are you looking for more on this Outcome Measure? Happy reading!

https://openaccess.leidenuniv.nl/bitstream/handle/1887/32283/08.pdf;jsessionid=AB13164F83375BED15641A053FCF03D9?sequence=12

References

1.         Luime JJ, Koes, B.W., Hendriksen, I.L., et al. . Prevalence and incidence of shoulder pain in the general population, a systematic review. Scand J Rheumatol. 2004;33:73-81.

2.         Chard MD, Halzleman, R., Hlazleman, B.L., King, R.H., & Reiss, B.B. Shoulder disorders in the elderly: a community survey. Arthritis Rheum. 1991;34(6):766-769.

3.         van der Windt DA, Koes, B.W., de Jong, B.A., & Bouter, L.M. Shoulder disorders in general practice: incidence, patient characteristics, and management. . Ann Rheum Dis. 1995;54(12):959-964.

4.         Arcuni SE. Rotator cuff pathology and subacromial impingement. Nurse Pract. 2000;25(5):58-66.

5.         Anderson VBW, E. . Impaired joint proprioception in higher shoulder elevations in chronic rotator cuff pathology. . Arch Phys Med Rehabil 2011;92:1146-1152.

6.         Holtby R RH. Measurement properties of the Western Ontario rotator cuff outcome measure: a preliminary report. Journal of shoulder and elbow surgery/American Shoulder and Elbow Surgeons. 2005;14(5):506-510.

7.         St-Pierre C, Dionne, C.E., Desmeules, F., & Roy, J.S. Reliability, validity, and responsiveness of a Canadian adaptation of the Western Ontario Rotator Cuff (WORC) index. Journal of Hand Therapy. 2015;28(3):292-298.

8.         Wessel RN, Lim, T.E., van Mameren, H., & de Bie, R.A. . Validation of the Western Ontario Rotator Cuff Index in patients with arthroscopic rotator cuff repair: A study protocol. BMC Musculoskeletal Disorders. 2011;12(64).

9.         Kirkley A, Alvarez C, Griffin S. The development and evaluation of a disease-specific quality-of-life questionnaire for disorders of the rotator cuff: The Western Ontario Rotator Cuff Index. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. Mar 2003;13(2):84-92.

10.       Harris JD, Pedroza, A., & Jones, G.L. Predictors of pain and function in patients with symptomatic, atraumatic full-thickness rotator cuff tears. Am J Sports Med. 2012;40(2):359-366.

11.       Wessel RN, Wolterbeek, N., Fermont, A.J.M., Lavrijsen, L., van Mameren, H., & de Bie, R.A. Responsiveness and disease specific of the Western Ontario Rotator Cuff Index. Journal of Orthopaedics. 2018;15(2):337-342. .

12.       Razmjou H BA, van Osnabrugge V, MacDermid JC, & Holtby R. Cross-sectional and longitudinal construct validity of two rotator cuff disease-specific outcome measures. BMC Musculoskeletal Disorders. 2006;7(26).

13.       Huber W HJ, Hanslik-Schnabel B, Posch M, & Wurnig C. [Translation and psychometric testing of the Western Ontario Rotator Cuff Index (WORC) for use in Germany]. Zeitschrift fur Orthopadie und ihre Grenzgebiete. 2005;143(4):453-460.

14.       Mousavi SJ HM, Abedi M, & Montazeri A. Translation and validation study of the Persian version of the Western Ontario Rotator Cuff Index. . Clinical Rheumatology. 2009;28(3):293-299.

15.       Ekeberg OM B-HE, Tveita EK, Keller A, Juel NG, & Brox JI. Agreement, reliability and validity in 3 shoulder questionnaires in patients with rotator cuff disease. . BMC Musculoskeletal Disorders. 2008;9(68).

16.       Lopes AD CR, Carrera EF, Griffin S, Faloppa F, & Dos Reis FB. . Validity and reliability of the Western Ontario Rotator Cuff Index (WORC) for use in Brazil. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. 2008;18(3):266-272.

17.       El O BC, Gulbahar S, Demiral Y, Sahin E, Baydar M, Kizil R, Griffin S, & Akalin E. The reliability and validity of the Turkish version of the Western Ontario Rotator Cuff Index. Rheumatol Int. 2006;26(12):1101-1108.

18.       Kirkley A GS, & Dainty K. Scoring systems for the functional assessment of the shoulder. Athroscopy. 2003;19(10):1109-1120.