Abstract
Background:
Oxford shoulder score is a specific 12-item patient-reported tool for evaluation of patients with inflammatory and degenerative disorders of the shoulder. Since its introduction, it has been translated and culturally adapted in some Western and Eastern countries. The aim of this study was to translate the Oxford Shoulder Score (OSS) in Persian and to test its validity and reliability in Persian speaking population in Iran.
Methods:
One hundred patients with degenerative or inflammatory shoulder problem participated in the survey in 2012. All patients completed the Persian version of OSS, Persian DASH and the SF-36 for testing validity. Randomly, 37 patients filled out the Persian OSS again three days after the initial visit to assess the reliability of the questionnaire.
Results:
Cronbach’s alpha coefficient was 0.93. The intraclass correlation coefficient was 0.93. In terms of validity, there was a significant correlation between the Persian OSS and DASH and SF-36 scores (P<0.001).
Conclusion:
The Persian version of the OSS proved to be a valid, reliable, and reproducible tool as demonstrated by high Cronbach’s alpha and Pearson’s correlation coefficients. The Persian transcript of OSS is administrable to Persian speaking patients with shoulder condition and it is understandable by them.
Keywords: Shoulder pain, Oxford shoulder score, Validation, Reliability, Iran
Introduction
Shoulder pain and disability are common chief complains presenting in current orthopedic practices. Shoulder pain is reported to be the third most frequent musculoskeletal symptom after low back and neck pain. In addition, shoulder pain is common in patients with degenerative or inflammatory disorders with 7% prevalence in the population. 1-3
Current literature shows that in the operative management of shoulder disorders, including arthroscopic shoulder procedures for rotator cuff, instability, adhesive capsulitis, biceps tendon disease, subacromion impingement and glenohumeral joint replacement, patient-reported shoulder specific clinical measures are being used widely. This indicates the importance of patients’ opinions regarding their health status and quality of life related to their presenting disease in order to assess treatment efficacy.
With recent trends toward multicentre, multidisciplinary, regional and international clinical studies, systemic reviews and meta-analysis, the standardization, validation and cultural adaptation of a patient-reported shoulder clinical outcome instrument is felt more than ever. Among these patient-based instruments, the Oxford Shoulder Score (OSS) is the only one that covers, not only shoulder pain frequency and severity, but also quality of life and activity of daily living affected by shoulder illness.
The OSS is a simple questionnaire that includes the perception of patients concerning their shoulder and related quality of daily activities; moreover, it is easy to administer by untrained people. This clinical measure, as a joint specific instrument, minimizes the influence of other simultaneous morbidities in the upper limb and has been reported as valid and reliable for degenerative and inflammatory disorders of the shoulder in many global studies.
Presently, there is not a shoulder-related quality of life assessment available for the Persian speaking population who live in Iran, Afghanistan, and Tajikistan. Hence, the purpose of this current study was to translate and culturally adapt the OSS in the Persian speaking population in Iran and consequently to evaluate its psychometric properties, reliability, and validity.
Material and Methods
Patients
The study included 100 consecutive patients referred to the shoulder clinic from January to August 2012. The inclusion criteria were having an inflammatory or degenerative shoulder disorder, and being a native literate Persian speaker. The exclusion criteria were patients with neuropathic pain, neoplasm, systemic inflammatory disease, and shoulder instability. The Internal Review Board (IRB) of Mashhad University of Medical Sciences has approved the protocol. Patients were consented before filling the questionnaire.
Translation
The original English OSS was developed by Dawson et al. and subsequently translated according to the guidelines and recommendations in the related literature. 4-6 Translators of the Persian version, included two Iranian orthopedic surgeons and an independent professional translator whose mother language was Persian. A coordination meeting was held and a common version of the Persian translation for the OSS was produced. We sent this Persian translated draft to an English-Persian translator, whose mother tongue was American English, to translate this Persian version to English. She was not aware of the study details and had not seen the English transcript of the OSS. Next, a second meeting of the translators was held and we compared the original English version and backward translated transcript. There was not a remarkable difference between the two. Finally, a consensus was reached for a final version of the Persian OSS (figure 1).
Figure 1.
Persian version of Oxford Shoulder Score that is validated for Persian speaking population.
The Oxford Shoulder Score (OSS)
The OSS was first developed by Dawson et al. in 1996.7 It is a patient reported questionnaire including 12 descriptors of pain and disability for shoulder ailments. Item rating ranges from 1 to 5 and the total score is from the summation of all 12 rated items from 12 (the best) to 60 (the worst).
Disabilities of the Arm Shoulder and Hand (DASH) Outcome Measure
The DASH (disabilities of the arm, shoulder and hand) outcome measure is a 30-item, self-report questionnaire designed to measure physical function and symptoms in patients with musculoskeletal disorders of the upper limbs. 8 The questionnaire was designed to describe the disability experienced by people with upper-limb disorders and to monitor changes in symptoms and function over time following treatments. 9 It is a reliable instrument for clinicians and clinical researchers that can be used to assess any or all joints in the upper extremity. 10,11 Furthermore, the DASH has been tested and approved in terms of construct validity and internal reliability in the Persian language by Mousavi et al. 12
The SF-36
The SF-36 is a generic, short-form health survey with only 36 questions that includes an 8-scale profile of functional health and well-being scores as well as psychometrically-based physical and mental health summary measures. The SF-36 has proven useful in surveys of general and specific populations, comparing the relative burden of diseases, and in differentiating the health benefits produced by a wide range of different treatments. 13 Among the most frequently used conditions are chronic musculoskeletal conditions, including osteoarthritis, back pain, and knee and shoulder disorders. 14-16 Moreover, its validity and reliability has been documented in many countries including Iran. 17
Psychometric Analysis
Construct Validity
Construct validity involves empirical and theoretical support for the interpretation of the construct of the clinical instrument. Convergent validity is testing the ratio of correlation between a new measure and other related measures, which are supposed to be correlated in a same field. In this study, we have used the already approved valid Persian DASH and Persian SF-36 survey to test the validity of the OSS. We assessed the statistical validity by calculating the Pearson correlation coefficient between OSS, DASH and SF-36.
Reliability
Reliability refers to the consistency of a measure; hence, a test is considered reliable if we could get the same result repeatedly. In our study, to measure test-retest reliability or reproducibility, the Persian OSS was administered twice at two different times. This kind of reliability is used to assess the consistency of a test across time. This type of reliability assumes that there will be no change in the quality or construct being measured. For this purpose, we randomly asked 37 participants to fill out the Persian OSS three days after the main study. Meanwhile, this retest portion of the patients did not receive major treatment such as surgery that may change their quality of health and symptoms substantially.
Internal Consistency
Internal consistency is a part of reliability testing that tests the consistency of the ratings across items in a same measure. In other words, we are comparing question items that measure the same construct to determine that the tests are internally consistent. Internal consistency was tested by means of the Cronbach’s alpha coefficient that calculates the internal correlations of all the items on the same scale (the Persian OSS). The Cronbach’s alpha coefficient indirectly evaluates the extent to which all of the 12 questions of the OSS measure the same construct. A high Cronbach’s alpha coefficient (range from 0 to 1) indicates more consistency.
The Cronbach’s alpha coefficient was also calculated for the elimination of 1 item out of the 12 questions. All question items were tested for correlation with the overall OSS. Statistical analyses were performed using SPSS 11.5 software (SPSS Inc, Chicago, IL). The value of P<0.05 was considered a significant difference.
Results
In the translation and cultural adaptation of the OSS to Persian, there was not a major problem. A total of 100 patients, who met the inclusion criteria for the study, filled out the Persian OSS, DASH and the SF-36 consequently. The range of the patients` age was between 25 to 77 years with an average of 43 table 1. The average time required for patients to complete the OSS form was 4 minutes and 40 seconds (range: 2-15 min).
Table 1.
Demographic characteristics of the patients with shoulder problems (N=100)
| Age, mean (SD) | 43 (15) |
| Gender, no. (%) | |
| Male | 49 (49) |
| Female | 51 (51) |
| Education, no. (%) | |
| Below high school | 72 (72) |
| High school and up | 28 (28) |
| Clinical diagnosis, no. (%) | |
| Subacromion Bursitis/impingement without RCT | 24 (24) |
| Rotator cuff tear (RCT) | 23 (23) |
| Biceps tenosynovitis | 11 (11) |
| Frozen shoulder | 30 (30 |
| Shoulder DJD | 5 (5) |
| ACJ DJD | 7 (7) |
| Side involved, no. (%) | |
| Dominant limb | 52 (52) |
| Nondominant limb | 30 (30) |
| Bilateral limbs | 18 (18) |
Reliability: Internal Consistency and Cronbach’s Alpha
For each item, test-retest assessment was performed with both of the ICCs and their internal consistency was high (Cronbach’s alpha = 0.93). The intraclass coefficient was 0.93 (95% confidence interval; range = 0.90-0.96).
Reproducibility
Thirty-seven patients once again filled out the Persian OSS 48 h later in order to test the test-retest reliability. The Pearson correlation was 0.86 (P<0.001) (table 2).
Table 2.
Correlation of OSS questions with each other (N=100)
| Indices | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 | Q10 | Q11 | Q12 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1 | |||||||||||
| r | 0.21 | 0.20 | 0.27 | 0.20 | 0.23 | 0.18 | 0.63 | 0.25 | 0.20 | 0.30 | 0.5 |
| P* | 0.039 | 0.046 | 0.0060 | 0.044 | 0.024 | 0.079 | <0.001 | 0.014 | 0.047 | 0.0030 | <0.001 |
| Q2 | |||||||||||
| r | 0.57 | 0.42 | 0.48 | 0.45 | 0.53 | 0.26 | 0.55 | 0.56 | 0.33 | 0.35 | |
| P* | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.010 | <0.001 | <0.001 | 0.0010 | <0.001 | |
| Q3 | |||||||||||
| r | 0.54 | 0.51 | 0.57 | 0.55 | 0.27 | 0.58 | 0.64 | 0.41 | 0.34 | ||
| P* | <0.001 | <0.001 | <0.001 | <0.001 | 0.0060 | <0.001 | <0.001 | <0.001 | <0.001 | ||
| Q4 | |||||||||||
| r | 0.51 | 0.58 | 0.47 | 0.31 | 0.45 | 0.46 | 0.42 | 0.32 | |||
| P* | <0.001 | <0.001 | <0.001 | 0.0020 | <0.001 | <0.001 | <0.001 | 0.0010 | |||
| Q5 | |||||||||||
| r | 0.74 | 0.43 | 0.20 | 0.53 | 0.50 | 0.44 | 0.29 | ||||
| P* | <0.001 | <0.001 | 0.042 | <0.001 | <0.001 | <0.001 | 0.0040 | ||||
| Q6 | |||||||||||
| r | 0.58 | 0.34 | 0.60 | 0.56 | 0.55 | 0.39 | |||||
| P* | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | |||||
| Q7 | |||||||||||
| r | 0.34 | 0.83 | 0.70 | 0.55 | 0.39 | ||||||
| P* | 0.0010 | <0.001 | <0.001 | <0.001 | <0.001 | ||||||
| Q8 | |||||||||||
| r | 0.38 | 0.28 | 0.44 | 0.50 | |||||||
| P* | <0.001 | 0.0040 | <0.001 | <0.001 | |||||||
| Q9 | |||||||||||
| r | 0.67 | 0.46 | 0.44 | ||||||||
| P* | <0.001 | <0.001 | <0.001 | ||||||||
| Q10 | |||||||||||
| r | 0.53 | 0.43 | |||||||||
| P* | <0.001 | <0.001 | |||||||||
| Q11 | |||||||||||
| r | 0.36 | ||||||||||
| P* | <0.001 | ||||||||||
Correlation is significant at the 0.05 level (2tailed).
Validity
In terms of construct validity, the Persian OSS revealed a good convergent validity with the individual scores of DASH (P<0.001). In addition, we compared the total average of the OSS scores with the eight dimensions of the SF-36 scores. There was a significant correlation (P = 0.025) between the Persian OSS to the domains of PF, RP, BP, SF, and PCS and insignificant correlation to the domains of GH, VT, and MH (table 3).
Table 3.
Validity expressed by Pearson correlation between the Persian OSS and DASH and SF36 (N=100)
| Indices | Dashwork | Dashmusic | PF | RP | BP | GH | VT | SF | RE | MH | PCS | MCS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OSS | ||||||||||||
| r | −0.59 | −0.49 | 0.48 | 0.43 | 0.63 | 0.13 | 0.20 | 0.35 | 0.22 | 0.13 | 0.55 | 0.12 |
| P | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.21 | 0.052 | <0.001 | 0.025 | 0.21 | <0.001 | 0.23 |
OSS: Oxford shoulder score, DASH: Disabilities of the arm shoulder and hand, PF: Physical functioning, RP: Rolephysical, BP: Bodily pain, GH=General health, VT: Vitality, SF: Social functioning, RE: Role emotional, MH: Mental health, PCS: Physical component summary, MCS: Mental component summary
Discussion
Shoulder pain and discomfort account for 7-25% of the general population. 18 In a study conducted by WHO-ILAR COPCORD on the prevalence of musculoskeletal complaints in a rural area in Iran, the shoulder was reported as the second most common and was as high as 22.7%. 19 As a result, modern shoulder surgery, arthroscopic sport medicine shoulder surgery, and joint replacement have drawn the attention of orthopedic surgeons in the recent two decades. Moreover, with the current trend toward multicenter studies and international meta-analysis, the need for the standardization of clinical measures has been felt more than before.
In shoulder medicine and surgery, it has been reported that clinical instruments are responsive, reproducible, reliable, and comprehensive. 20-22 The OSS is a short questionnaire that consists of 12 items. It covers both general health related to shoulder impairment and specific questions on shoulder pain and function. The context of the questions is easy, simple, and comprehensible for patients; hence, explanatory instructions are not needed for independent usage by the patient. Although the OSS was first introduced for prospective studies, Wilson et al. recently reported that it is valid for retrospective application such as shoulder acute trauma wherein a prospective measurement is not possible. 23 Younis et al. recently studied the range of the OSS in the asymptomatic population in the UK,24 the benefit of the study is that disease severity can be gauged in relation to the normal population of the index community and post-operative improvements can be predicted more accurately.
The OSS was presented by Dawson et al. as a disease specific patient-based questionnaire to evaluate inflammatory and degenerative disorders of the shoulder in 1996.7 Since then, it has been widely used in the clinical assessment results of both operative and conservative treatments. It has been validated in several languages and cultures, including French, Turkish, German, Dutch, Italian, and Korean. 25-30 However, to date, there is not a Persian transcript of the OSS available with psychometric properties testing.
Different static measurements have been reported to examine the agreement and reliability of the questionnaires. In our study, the Cronbach`s alpha coefficient of 0.93 and the intraclass coefficients of each score of the OSS ranged from 0.90 to 0.96, being an excellent value for the Persian OSS to show reliability, which confirms a high internal consistency of the Persian OSS. The Pearson correlation between test and retest was calculated as -0.86. Persian version of the OSS has sufficient agreement and reliability when compared with the original and other culturally adapted versions (figure 2).
Figure 2.
Cronbach’s alpha of the original and other culturally adapted versions are illustrated in the diagram.
In terms of construct validity, which is an important index for achieving a comprehensive a clinical score, we have calculated the Pearson`s correlation between the total score achieved by the Persian OSS to the 8 dimensions of the Persian SF-36 as well as the Persian DASH, which was simultaneously filled out by our patients. There was a significant Pearson`s correlation coefficient between the total Persian OSS to PF, RP, BP, SF, PCS domains and insignificant correlation to GH, VT, MH domains. In addition, the Persian OSS revealed a good convergent validity with the individual scores of DASH. Pearson`s correlation for validity testing in other versions of the OSS was calculated in relation with the SF-36 and DASH.
The strength of our study is that we have included two generic health related quality of life measures; the SF-36 and DASH, which generally express mental and general health conditions, vitality, and social functioning of the patient and these two, were used to test the construct validity of the Persian OSS. The limitation of our study was the diversity of cultures and Persian accents among the patients because they were referred to a level-I hospital.
Conclusion
This study indicates that our Persian transcript of the Oxford Shoulder Score is as valid version to be applied among the Iranian population.
Conflict of Interest: None declared.
References
- 1.Luime JJ, Koes BW, Hendriksen IJ, Burdorf A, Verhagen AP, Miedema HS, et al. Prevalence and incidence of shoulder pain in the general population;a systematic review. Scand J Rheumatol. 2004;33:73–81. doi: 10.1080/03009740310004667. [DOI] [PubMed] [Google Scholar]
- 2.Greving K, Dorrestijn O, Winters JC, Groenhof F, van der Meer K, Stevens M, et al. Incidence, prevalence, and consultation rates of shoulder complaints in general practice. Scand J Rheumatol. 2012;41:150–5. doi: 10.3109/03009742.2011.605390. [DOI] [PubMed] [Google Scholar]
- 3.Feleus A, Bierma-Zeinstra SM, Miedema HS, Bernsen RM, Verhaar JA, Koes BW. Incidence of non-traumatic complaints of arm, neck and shoulder in general practice. Man Ther. 2008;13:426–33. doi: 10.1016/j.math2007.05.010. [DOI] [PubMed] [Google Scholar]
- 4.Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health-related quality of life measures:literature review and proposed guidelines. JClin Epidemiol. 1993;46:1417–32. doi: 10.1016/0895-4356(93)90142-N. [DOI] [PubMed] [Google Scholar]
- 5.Acquadro C, Jambon B, Ellis D, Marquis P. Language and translation issues. In: Spilker B, editor. Quality of life and pharmacoeconomics in clinical trials. Philadelphia: Lippincott; 1996. pp. 575–85. [Google Scholar]
- 6.Anderson RT, MacFarlane M, Naughton MJ, Shumaker SA. 2nd ed. Philadelphia: Lippincott; 1996. Conceptual issues and considerations in cross-cultural validation of generic health-related quality of life instruments. [Google Scholar]
- 7.Dawson J, Fitzpatrick R, Carr A. Questionnaire on the perceptions of patients about shoulder surgery. J Bone Joint Surg Br. 1996;78:593–600. [PubMed] [Google Scholar]
- 8.Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure:the DASH (disabilities of the arm, shoulder and hand) [corrected] The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602–8. doi: 10.1002/(SICI)1097-0274(199606)29:6<602::AID-AJIM4>3.0.CO;2-L. [DOI] [PubMed] [Google Scholar]
- 9.Kennedy CA, Beaton DE, Smith P, Van Eerd D, Tang K, Inrig T, et al. Measurement properties of the QuickDASH (disabilities of the arm, shoulder and hand) outcome measure and cross-cultural adaptations of the QuickDASH:a systematic review. Qual Life Res. 2013;22:2509–47. doi: 10.1007/s11136-013-0362-4. [DOI] [PubMed] [Google Scholar]
- 10.Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure:the DASH (disabilities of the arm, shoulder and hand) [corrected] The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602–8. doi: 10.1002/(SICI)1097-0274(199606)29:6<602::AID-AJIM4>3.0.CO;2-L. [DOI] [PubMed] [Google Scholar]
- 11.Alotaibi NM. The cross-cultural adaptation of the disability of arm, shoulder and hand (DASH):a systematic review. Occup Ther Int. 2008;15:178–90. doi: 10.1002/oti.252. [DOI] [PubMed] [Google Scholar]
- 12.Mousavi SJ, Parnianpour M, Abedi M, Askary-Ashtiani A, Karimi A, Khorsandi A, et al. Cultural adaptation and validation of the Persian version of the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure. Clin Rehabil. 2008;22:749–57. doi: 10.1177/0269215508085821. [DOI] [PubMed] [Google Scholar]
- 13.Ebrahimzadeh MH, Shojaei BS, Golhasani-Keshtan F, Soltani-Moghaddas SH, Fattahi AS, Mazloumi SM. Quality of life and the related factors in spouses of veterans with chronic spinal cord injury. Health Qual Life Outcomes. 2013;11:48. doi: 10.1186/1477-7525-11-48. [ PMC Free Article] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Diniz Lopes A, Ciconelli RM, Carrera EF, Griffin S, Faloppa F, Baldy dos Reis F. Comparison of the responsiveness of the Brazilian version of the Western Ontario Rotator Cuff Index (WORC) with DASH, UCLA and SF-36 in patients with rotator cuff disorders. Clin Exp Rheumatol. 2009;27:758–64. [PubMed] [Google Scholar]
- 15.Gandhi R, Tsvetkov D, Dhottar H, Davey JR, Mahomed NN. Quantifying the pain experience in hip and knee osteoarthritis. Pain Res Manag. 2010;15:224–8. doi: 10.1155/2010/578167. [ PMC Free Article] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Becerra Fontal JA, BagóGranell J, GarréOlmo J, Roig Busquets R, Peris Prats F, Villanueva Leal C. Evaluation of health-related quality of life in patients candidate for spine and other musculoskeletal surgery. Eur Spine J. 2013;22:1002–9. doi: 10.1007/s00586-012-2617-0. [ PMC Free Article] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Montazeri A, Goshtasebi A, Vahdaninia M, Gandek B. The Short Form Health Survey (SF-36):translation and validation study of the Iranian version. Qual Life Res. 2005;14:875–82. doi: 10.1007/s11136-004-1014-5. [DOI] [PubMed] [Google Scholar]
- 18.Bjelle A. Epidemiology of shoulder problems. Baillieres Clin Rheumatol. 1989;3:437–51. doi: 10.1016/S0950-3579(89)80003-2. [DOI] [PubMed] [Google Scholar]
- 19.Davatchi F, Tehrani Banihashemi A, Gholami J, Faezi ST, Forouzanfar MH, Salesi M, et al. The prevalence of musculoskeletal complaints in a rural area in Iran:a WHO-ILAR COPCORD study (stage 1, rural study) in Iran. Clin Rheumatol. 2009;28:1267–74. doi: 10.1007/s10067-009-1234-8. [DOI] [PubMed] [Google Scholar]
- 20.Ekeberg OM, Bautz-Holter E, Tveitå EK, Keller A, Juel NG, Brox JI. Agreement, reliability and validity in 3 shoulder questionnaires in patients with rotator cuff disease. BMC Musculoskelet Disord. 2008;9:68. doi: 10.1186/1471-2474-9-68. [ PMC Free Article] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Roy JS, MacDermid JC, Woodhouse LJ. Measuring shoulder function:a systematic review of four questionnaires. Arthritis Rheum. 2009;61:623–32. doi: 10.1002/art.24396. [DOI] [PubMed] [Google Scholar]
- 22.Linsell L, Dawson J, Zondervan K, Rose P, Randall T, Fitzpatrick R, et al. Prevalence and incidence of adults consulting for shoulder conditions in UK primary care;patterns of diagnosis and referral. Rheumatology (Oxford) 2006;45:215–21. doi: 10.1093/rheumatology/kei139. [DOI] [PubMed] [Google Scholar]
- 23.Wilson J, Baker P, Rangan A. Is retrospective application of the Oxford Shoulder Score valid?J Shoulder Elbow Surg. 2009; 18:577–80. doi: 10.1016/j.jse.2009.02.024. [DOI] [PubMed] [Google Scholar]
- 24.Younis F, Sultan J, Dix S, Hughes PJ. The range of the Oxford Shoulder Score in the asymptomatic population:a marker for post-operative improvement. Ann R Coll Surg Engl. 2011;93:629–33. doi: 10.1308/003588411X13165261994193. [ PMC Free Article] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Huber W, Hofstaetter JG, Hanslik-Schnabel B, Posch M, Wurnig C. The German version of the Oxford Shoulder Score--cross-cultural adaptation and validation. Arch Orthop Trauma Surg. 2004;124:531–6. doi: 10.1007/s00402-004-0716-z. [DOI] [PubMed] [Google Scholar]
- 26.Tuğay U, Tuğay N, Gelecek N, Özkan M. Oxford Shoulder Score:cross-cultural adaptation and validation of the Turkish version. Arch Orthop Trauma Surg. 2011;131:687–94. doi: 10.1007/s00402-010-1242-9. [DOI] [PubMed] [Google Scholar]
- 27.Murena L, Vulcano E, D'Angelo F, Monti M, Cherubino P. Italian cross-cultural adaptation and validation of the Oxford Shoulder Score. J Shoulder Elbow Surg. 2010;19:335–41. doi: 10.1016/j.jse.2009.07.068. [DOI] [PubMed] [Google Scholar]
- 28.Frich LH, Noergaard PM, Brorson S. Validation of the Danish version of Oxford Shoulder Score. Dan Med Bull. 2011;58:A4335. [PubMed] [Google Scholar]
- 29.Berendes T, Pilot P, Willems J, Verburg H, te Slaa R. Validation of the Dutch version of the Oxford Shoulder Score. J Shoulder Elbow Surg. 2010;19:829–36. doi: 10.1016/j.jse.2010.01.017. [DOI] [PubMed] [Google Scholar]
- 30.Roh YH, Noh JH, Kim W, Oh JH, Gong HS, Baek GH. Cross-cultural adaptation and validation of the Korean version of the Oxford shoulder score. Arch Orthop Trauma Surg. 2012;132:93–9. doi: 10.1007/s00402-011-1393-3. [DOI] [PubMed] [Google Scholar]