Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-2946-0
HIP
Transcultural adaptation of the Korean version of the Hip Outcome Score Young-Kyun Lee • Yong-Chan Ha • RobRoy L. Martin • Deuk-Soo Hwang Kyung-Hoi Koo
•
Received: 18 April 2013 / Accepted: 10 March 2014 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The Hip Outcome Score (HOS) is a questionnaire commonly used to assess the clinical outcome of patients after hip arthroscopy. However, a Korean version of the HOS is not available. The aim of this study was to translate and adapt the HOS questionnaire into the Korean language and then assess the psychometric properties of this instrument. Methods Translation and transcultural adaptation of the HOS into Korean (HOS-K) was performed in accordance with the international recommendations. Sixty patients (mean age 38.4 years) planning hip arthroscopy participated in evaluating the psychometric properties of the HOS-K. Psychometric analyses consisted of assessing for the following: (1) floor/ceiling effects, (2) internal consistency Electronic supplementary material The online version of this article (doi:10.1007/s00167-014-2946-0) contains supplementary material, which is available to authorized users. Y.-K. Lee K.-H. Koo Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea Y.-C. Ha (&) Department of Orthopaedic Surgery, College of Medicine, Chung-Ang University, 224-1 Heukseok-dong, Dongjak-gu, Seoul 156-755, South Korea e-mail: [email protected] R. L. Martin Department of Physical Therapy, Duquesne University, UPMC Center for Sports Medicine, Pittsburgh, PA, USA D.-S. Hwang Department of Orthopedic Surgery, School of Medicine, Chungnam National University, 33 Munhwa-ro, Jung-gu, Taejon 301-721, South Korea
using Cronbach’s alpha, (3) test–retest reliability over 2–3 weeks with intraclass correlation coefficient (ICC), (4) convergent validity by correlation with the SF-36 and Hip disability and Osteoarthritis Outcome Score (HOOS), (5) construct validity by assessing for a difference in HOS-K scores based on a rating of hip function, and (6) responsiveness with a change in score over a 6-month period. Results The English version of the HOS was translated and adapted to Korean without notable discrepancies. The HOS-K scores were reliable with ICC of 0.946 for the activities of daily living (ADL) subscale and 0.929 for the sports subscale. Internal consistency was confirmed by Cronbach’s alpha [0.90 for both subscales. Both subscales had a strong correlation to the five subscales of SF-36, except the general health subscale. The ADL subscale showed strong correlations with all the subscales of the HOOS, and sports subscale showed strong correlations with all subscales of the HOOS, except the symptom subscales of HOOS. The HOS-K also demonstrated evidence for responsiveness without floor and ceiling effects. Conclusion The HOS-K can be recommended as an outcome instrument in hip arthroscopy for Korean-speaking individuals. Surgeons can use the HOS-K to evaluate the outcome of hip arthroscopy in Korea. Level of evidence Therapeutic case series with no comparison group, Level IV. Keywords Hip Outcome Score Reliability Validity Responsiveness Transcultural adaptation
Introduction The Hip Outcome Score (HOS) was developed specifically to evaluate the clinical outcomes for hip arthroscopy in
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Knee Surg Sports Traumatol Arthrosc
English-speaking patients [11]. The HOS has been widely used in research [10, 16, 19] and had evidence of its reliability, validity, and responsiveness to support its use [12, 13, 19]. For a wider application of such assessment tools and questionnaires, translation and transcultural adaptation from its original version is necessary. In addition, international guidelines suggest that the transculturally adapted version be tested in terms of psychometric properties [1]. Hip arthroscopy is a well-established surgical option for the treatment of intraarticular pathology, such as femoroacetabular impingement and labral tears, and it is one of the most commonly performed orthopaedic surgical procedures in the Asian countries [3, 4, 18]. Currently, there is a lack of evidence to support the use of a questionnaire to assess outcomes for Korean-speaking individuals after hip arthroscopy. The information acquired from an outcome questionnaire is useful only if there is evidence to support interpretation of the obtained scores. Although the HOS is used worldwide and has been translated into different languages [16], no study has evaluated the HOS in an Asian population. Furthermore, there is no Korean version of the HOS. The aim of this study was to translate and adapt the HOS questionnaire into the Korean language and test the psychometric properties of the Korean version of HOS (HOSK), in terms of reliability, validity, and responsiveness.
Materials and methods Translation and transcultural adaptation from English to Korean was conducted according to the standardized international recommendations [1]. Similar procedures have been successfully completed with other instruments [8, 9]. The study was divided into two parts: (1) translation and transcultural adaptation of the English version of the HOS instrument into the Korean language and (2) testing of the psychometric properties of the HOS-K in patients planning to undergo hip arthroscopy. Based on recommendations by Beaton et al [1], 60 adult patients (34 men and 26 women; median age 37 years, and range 16–80 years) planning to undergo hip arthroscopy in two hospitals between June 2011 and February 2012 were enroled to test the psychometric properties of the HOS-K. The diagnosis for these individuals was labral tear (n = 39), FAI (n = 19) and snapping hip (n = 2). Translation and transcultural adaptation Forward translation and reconciliation were done by two individuals (native Korean speakers fluent in English; one orthopaedic surgeon, and one non-orthopaedic translator) who independently translated the English version of HOS
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into Korean. At a consensus meeting attended by the two translators who performed the forward translation, and three orthopaedic surgeons (YKL, YCH, and KHK), a single Korean version was obtained by reconciling these two Korean versions. The reconciled Korean version was then translated back into English by two bilingual native English speakers, who were both Korean-Americans fluent in Korean (one a medical personnel and the other a nonmedical personnel) and were blinded to the original English version. To assess for harmonization, the back-translated and original versions of the HOS were reviewed by a consensus committee, which included the two translators, three orthopaedic surgeons, one medical personnel, and a research assistant specialized in orthopaedic scoring systems. Each committee member independently compared the back-translated and original HOS versions on an itemby-item basis and scored the equivalence with the originals semantically, idiomatically, experientially, and conceptually [1], as follows: ‘‘not equivalent at all’’ (0), ‘‘mildly equivalent’’ (1), ‘‘moderately equivalent’’ (2), ‘‘nearly equivalent’’ (3), and ‘‘totally equivalent’’ (4) [8, 9]. After averaging the individual item scores, the translated Korean expressions for the items with an average equivalence score of less than 3 (nearly equivalent) were discussed and revised to establish the final version of the HOS-K. During the harmonization process for transcultural adaptation, the average of the transcultural equivalence scores was less than 3 (nearly equivalent) in two items (‘‘running one mile’’ and ‘‘cutting/lateral movements’’ of the sports subscales). During the discussion of these two items, the committee checked that the translation was comprehensive and confirmed the transcultural equivalence of the original English and final Korean versions. The final HOS-K was pretested by 20 Korean outpatients visiting the Department of Orthopedic Surgery at our hospital. The patients completed the questionnaire and were then interviewed for a complete comprehension and to identify any possible difficulties in completing the HOS-K. Psychometric evidence Once enroled in the study, all subjects completed the HOS-K. Two to three weeks later, at the time of hospital admission for surgery, subjects completed the HOS-K again to evaluate test–retest reliability. This time, the subjects did not receive any intervention. Subjects then underwent hip arthroscopy and completed the HOS-K 6 months after their surgery. At the second administration of the HOS-K (2–3 weeks interval), subjects also completed the Korean version of Short Form-36 (SF-36) [6], the Korean version of Hip disability and Osteoarthritis Outcome Score (HOOS) [8], and a rating of overall hip
Knee Surg Sports Traumatol Arthrosc
function (normal, nearly normal, abnormal, or severely abnormal) to evaluate convergent and construct validities. The SF-36 is a valid and reliable generic health status questionnaire containing eight subscales: physical function (PF), role limitations because of physical problems (RP), bodily pain (BP), general health perception (GH), vitality (V), social function (SF), role limitations because of emotional problems (RE), and mental health (MH) [21]. The Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire was a hip-specific questionnaire, which was developed as an extension of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire to provide improved validity for young and active patients with high physical function demands [2, 7, 17]. The HOOS includes five subscales, i.e. symptoms, pain, activity of daily living (ADL), sports/ recreation, and quality of life (QoL). This study was approved by the institutional review board of our hospital (Seoul National University Bundang Hospital, B-1003-095-001), and written informed consent was obtained from all patients.
validity, the correlation between the HOS-K and all HOOS subscales and the subscales of the SF-36 questionnaire was tested using the Spearman’s rank correlation. A Spearman’s rho of [0.50, 0.35–0.50, and \0.35 was considered strong, moderate, and weak correlations, respectively [22]. Construct validity was assessed with hypothesis testing to determine whether the HOS-K would perform as expected with significantly different scores based on the category of an overall rating of hip function. Differential ability for individuals with different status was tested by one-way analysis of variance (ANOVA) and post hoc analysis. The responsiveness, which is a measure of the changes that occur in an individual over a period of time, was evaluated by comparing the pre-arthroscopy and 6-month post-arthroscopy results of the HOS, as determined by using the Wilcoxon signed-rank test. Statistical analysis was performed using SPSS version 15.0 (SPSS, Chicago, IL), and p values of \0.05 were considered significant.
Results Statistical analysis Translation and transcultural adaptation Floor and ceiling effects, the internal consistency, test– retest reliability, convergent validity, construct validity, and responsiveness were evaluated to test the psychometric properties of the HOS-K. The scores from the initial administration of the HOS-K were used to asses for floor and ceiling effects and internal consistency. The proportion of individuals who achieved the highest and lowest possible score was calculated to determine floor and ceiling effects. Floor and ceiling effects were considered present when more than 15 % of the respondents reached the highest or lowest possible score [14]. The internal consistency, which is the degree of homogeneity of the items within each subscale, was assessed using Cronbach’s alpha coefficient. A Cronbach’s alpha coefficient of ]0.7 was considered satisfactory [5]. The test–retest reliability was assed using the scores obtained initially and those obtained 2–3 weeks later. Three weeks was considered long enough to prevent recall, but sufficiently short to ensure that the hip status would not change significantly [15]. Test–retest reliability is the stability across repeated measures and was evaluated using the intraclass correlation coefficient (ICC) (two-way random effect model, assuming a single measurement and absolute agreement) with 95 % confidence intervals. An ICC of[0.70 was considered to indicate good reliability [8]. The convergent validity, which is a type of construct validity, suggests that the value of one parameter would have a quantitative relationship with another similar value of a different parameter. To measure the convergent
During the harmonization process for transcultural adaptation, two items (‘‘running one mile’’ and ‘‘cutting/lateral movements’’) had an average transcultural equivalence score of less than 3 (nearly equivalent). During the discussion of these items, the consensus committee checked that the translation was comprehensive, and a liberal translation was necessary. The committee confirmed the transcultural equivalence of the original English and final Korean versions (supplementary material). Test of the psychometric properties of the final Korean version of the HOS All 60 patients completed the questionnaire for assessment of internal consistency. All 60 patients were admitted for hip arthroscopy and completed the second HOS questionnaire for assessment of test–retest reliability. At this time, all 60 subjects also completed the SF-36, HOOS, and a rating of overall hip function for assessment of validity (Table 1). The final HOS-K was completed by 52 subjects for an assessment of responsiveness 6 months post-operatively (Table 3). No floor or ceiling effect was observed. Cronbach’s alpha was 0.948 in ADL subscale and 0.958 in sports subscale, indicating no heterogeneity. The test–retest reliability was confirmed with an ICC of 0.946 (95 % CI 0.905–0.969) in ADL subscale and 0.929 (95 % CI 0.877–0.959) in sports subscale.
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Knee Surg Sports Traumatol Arthrosc Table 1 Convergent validity of Korean HOS (n = 60)
Score (mean ± SD)
ADL subscale of HOS
70.5 ± 18.7
Sports subscale of HOS
50.1 ± 28.2
Correlation with sports subscale
Spearman R
Spearman R
p value
p value
SF-36 PF
36.7 ± 10.7
0.685
\0.001
0.646
\0.001
SF-36 RP
35.9 ± 12.4
0.574
\0.001
0.718
\0.001
SF-36 BP
39.4 ± 10.6
0.585
\0.001
0.623
\0.001
SF-36 GH
42.0 ± 7.6
0.129
n.s.
0.121
n.s.
SF-36 VT SF-36 SF
45.0 ± 11.1 38.3 ± 12.6
0.446 0.518
0.006 0.001
0.440 0.672
0.006 \0.001 \0.001
SF-36 RE
33.5 ± 15.3
0.522
0.001
0.665
SF-36 MH
41.8 ± 10.3
0.426
0.010
0.351
0.036
HOOS symptom
64.7 ± 19.6
0.569
\0.001
0.385
0.020
HOOS pain
64.7 ± 22.2
0.649
\0.001
0.545
\0.001
HOOS ADL
68.0 ± 21.5
0.784
\0.001
0.620
\0.001
HOOS Sports
54.1 ± 22.5
0.762
\0.001
0.593
\0.001
HOOS QoL
38.5 ± 24.0
0.589
\0.001
0.568
\0.001
HOOS total
63.4 ± 19.5
0.684
\0.001
0.529
0.001
Table 2 Mean Korean HOS according to rating of overall hip function ADL (mean ± SD)
Table 3 Responsiveness of the Korean HOS
Sports (mean ± SD)
Normal
97.5 ± 3.5
97.5 ± 3.5
Nearly normal
78.7 ± 4.7
69.5 ± 13.9
Abnormal
69.3 ± 13.8
47.5 ± 16.1
Severely abnormal
15.0 ± 7.1
17.5 ± 3.5
The convergent validity for the HOS was observed by the strong correlations between the ADL and sports subscale of HOS scores and the five relevant SF-36 subscales, including the PF, RP, BP, SF, and RE. The general health subscale was the subscale that did not correlate with the ADL and sports activity subscale of HOS (n.s) (Table 1). In terms of the convergent validity with the HOOS, all subscales of the HOOS showed strong correlations with the ADL subscale of HOS scores. All subscales of the HOOS showed strong correlations with the sports subscale of HOS scores, except the symptom subscales of HOOS (Table 1). Overall hip function of patients was rated as normal in 2 patients (3.3 %), nearly normal in 20 (33.3 %), abnormal in 36 (60 %), and severely abnormal in 2 (3.3 %). One-way ANOVA and post hoc comparison showed that the scores for patients were significantly different from one another for both ADL and sports subscales (p \ 0.05), except those between patients rating their hip function as normal and those rating it as nearly normal (Table 2). For the responsiveness, each item of the HOS score improved significantly after hip arthroscopy (Table 3).
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Correlation with ADL subscale
ADL subscale Sports subscale
Preoperative score (mean ± SD)
Post-operative score (mean ± SD)
p value
70.5 ± 18.7
78.6 ± 12.8
0.006
50.1 ± 28.2
65.6 ± 28.6
0.001
Discussion The most important finding of the present study was that the transculturally adapted Korean version of HOS was a reliable, valid, and responsive questionnaire without floor and ceiling effects. These results are similar to those found in other language version of the HOS [12, 16]. The HOS-K can be recommended as an outcome instrument in hip arthroscopy for Korean-speaking individuals. The HOOS and Oxford hip score are hip-specific instruments that have been translated into Korean [8, 9]. However, systematic reviews found the HOS to have the most robust evidence and to be the best available outcome questionnaire for evaluating hip arthroscopy [10, 19, 20]. Evidence of its reliability, validity, and responsiveness is available for the original English HOS [11–13] as well as the German version (HOS-D) [16]. Similar to the results of this study of the HOS-K, the English HOS and HOS-D also correlated appropriately to generic outcome measures [12, 16], with HOS-D also correlating to scores on hip-specific measures [16]. Related to evidence for responsiveness,
Knee Surg Sports Traumatol Arthrosc Table 4 Comparison with other language version of HOS HOS ADL
HOS-D Sports
ADL
HOS-K Sports
ADL
Sports
Internal consistency
0.96
0.95
0.95
0.91
0.948
0.958
Test–retest reliability
0.98
0.92
0.94
0.89
0.946
0.929
Scores according to reported level of function Normal 96 94 96.6 95.3 Nearly normal
89
78
83.8
64
97.5
97.5
78.7
69.5
Abnormal
64
40
66.7
41.1
69.3
47.5
Severely abnormal
31
6
62.1
34.3
15
17.5
significant differences between pre- and post-operative scores were noted for both the English HOS and HOS-K [13]. Similar results were also found when defining internal consistency, test–retest reliability, and ability to differentiate individuals based on reported levels of function when comparing the English HOS, HOS-D, and HOS-K [11–13, 16] (Table 4). The most noticeable difference between the three instruments was the scores obtained from those with severely abnormal function. The higher scores obtained for the HOS-D may be attributed to a younger groups of subjects (mean age 33 years) used in the study [16]. The mean ages of the subjects in this study of the HOS-K and the study providing similar evidence for English HOS were 38.4 and 44.2 years, respectively [12]. During the translation and transcultural adaptation process, a careful discussion of some items was required to ensure that their meanings were retained accurately. Since many Koreans cannot understand the anatomic term ‘‘hip’’, as they use other terms, corresponding to the groin, inguinal, buttocks, and thigh to indicate the hips, a sentence defining the anatomic term ‘‘hip’’ was added to the header of the HOS-K, as has been done elsewhere [8, 9]. In addition, Korean culture differs substantially from that in the West, particularly in terms of length unit. Although the term ‘‘running one mile’’ appears in the original HOS, unlike the West, many Koreans do not use the imperial unit system (mile), but rather use the metric unit system (kilometre). We changed ‘‘running one mile’’ to ‘‘running 1 to 2 km’’. The term ‘‘cutting/lateral movements’’ appears in the original HOS. However, unlike the West, many Asian people interpret ‘‘cutting’’ as ‘‘sever’’. Therefore, we used Korean wordings that mean ‘‘block the way’’, instead of ‘‘cutting’’. All these crosslanguage and transcultural issues were addressed and discussed to achieve consensus. This study has limitations. First, this study was conducted in Korea, and thus, caution should be exercised when making generalizations in other Asian countries.
Second, we included the small number of patients with extraarticular pathology such as snapping hip. The results of this research offer evidence to support the use of the HOS-K in hip arthroscopy for Korean-speaking individuals. This study shows that the HOS is a relevant questionnaire in the Eastern as well as in the Western populations, after carrying out the required transcultural adaptation process. In the present study, HOS was translated and adapted transculturally into the Korean language according to the international guidelines. Furthermore, the HOS-K demonstrated relevant internal consistency, reliability, convergent validity, construct validity, and responsiveness, which was comparable to versions written in different languages. Physicians can therefore use the HOS-K to evaluate the outcome of hip arthroscopy in Korea.
Conclusion This study has demonstrated that the Korean version of HOS translated according to the international guidelines was a reliable, valid, and responsive questionnaire without floor and ceiling effects.
References 1. Beaton DE, Bombardier C, Guillemin F, Ferraz MB (2000) Guidelines for the process of cross-cultural adaptation of selfreport measures. Spine (Phila Pa 1976) 25(24):3186–3191 2. Bellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW (1988) Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol 15(12):1833–1840 3. Byrd JW, Jones KS (2009) Hip arthroscopy for labral pathology: prospective analysis with 10-year follow-up. Arthroscopy 25(4):365–368 4. Colvin AC, Harrast J, Harner C (2012) Trends in hip arthroscopy. J Bone Joint Surg Am 94(4):e231–e235 5. Cronbach L, Warrington W (1951) Time-limit tests: estimating their reliability and degree of speeding. Psychometrika 16(2):167–188 6. Han CW, Lee EJ, Iwaya T, Kataoka H, Kohzuki M (2004) Development of the Korean version of Short-Form 36-Item Health Survey: health related QOL of healthy elderly people and elderly patients in Korea. Tohoku J Exp Med 203(3):189–194 7. Klassbo M, Larsson E, Mannevik E (2003) Hip disability and osteoarthritis outcome score. An extension of the Western Ontario and McMaster Universities Osteoarthritis Index. Scand J Rheumatol 32(1):46–51 8. Lee YK, Chung CY, Koo KH, Lee KM, Lee DJ, Lee SC, Park MS (2011) Transcultural adaptation and testing of psychometric properties of the Korean version of the Hip Disability and Osteoarthritis Outcome Score (HOOS). Osteoarthr Cartil 19(7):853–857 9. Lee YK, Chung CY, Park MS, Lee KM, Lee DJ, Lee SC, Koo KH (2012) Transcultural adaptation and testing of psychometric properties of the Korean version of the Oxford hip score. J Orthop Sci 17(4):377–381
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Knee Surg Sports Traumatol Arthrosc 10. Lodhia P, Slobogean GP, Noonan VK, Gilbart MK (2011) Patient-reported outcome instruments for femoroacetabular impingement and hip labral pathology: a systematic review of the clinimetric evidence. Arthroscopy 27(2):279–286 11. Martin RL, Kelly BT, Philippon MJ (2006) Evidence of validity for the hip outcome score. Arthroscopy 22(12):1304–1311 12. Martin RL, Philippon MJ (2007) Evidence of validity for the hip outcome score in hip arthroscopy. Arthroscopy 23(8):822–826 13. Martin RL, Philippon MJ (2008) Evidence of reliability and responsiveness for the hip outcome score. Arthroscopy 24(6):676–682 14. McHorney CA, Tarlov AR (1995) Individual-patient monitoring in clinical practice: are available health status surveys adequate? Qual Life Res 4(4):293–307 15. McKelvie SJ (1992) Does memory contaminate test-retest reliability? J Gen Psychol 119(1):59–72 16. Naal FD, Impellizzeri FM, Miozzari HH, Mannion AF, Leunig M (2011) The German Hip Outcome Score: validation in patients undergoing surgical treatment for femoroacetabular impingement. Arthroscopy 27(3):339–345 17. Nilsdotter AK, Lohmander LS, Klassbo M, Roos EM (2003) Hip disability and osteoarthritis outcome score (HOOS)–validity and
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responsiveness in total hip replacement. BMC Musculoskelet Disord 4:10 Philippon MJ, Schroder ESBG, Briggs KK (2012) Hip arthroscopy for femoroacetabular impingement in patients aged 50 years or older. Arthroscopy 28(1):59–65 Thorborg K, Roos EM, Bartels EM, Petersen J, Holmich P (2010) Validity, reliability and responsiveness of patient-reported outcome questionnaires when assessing hip and groin disability: a systematic review. Br J Sports Med 44(16):1186–1196 Tijssen M, van Cingel R, van Melick N, de Visser E (2011) Patient-reported outcome questionnaires for hip arthroscopy: a systematic review of the psychometric evidence. BMC Musculoskelet Disord 12:117 Ware JE Jr, Sherbourne CD (1992) The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 30(6):473–483 Xie F, Thumboo J, Lo NN, Yeo SJ, Yang KY, Yeo W, Chong HC, Fong KY, Li SC (2007) Cross-cultural adaptation and validation of Singapore English and Chinese versions of the Lequesne Algofunctional Index of knee in Asians with knee osteoarthritis in Singapore. Osteoarthr Cartil 15(1):19–26
HIP
Transcultural adaptation of the Korean version of the Hip Outcome Score Young-Kyun Lee • Yong-Chan Ha • RobRoy L. Martin • Deuk-Soo Hwang Kyung-Hoi Koo
•
Received: 18 April 2013 / Accepted: 10 March 2014 Ó Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The Hip Outcome Score (HOS) is a questionnaire commonly used to assess the clinical outcome of patients after hip arthroscopy. However, a Korean version of the HOS is not available. The aim of this study was to translate and adapt the HOS questionnaire into the Korean language and then assess the psychometric properties of this instrument. Methods Translation and transcultural adaptation of the HOS into Korean (HOS-K) was performed in accordance with the international recommendations. Sixty patients (mean age 38.4 years) planning hip arthroscopy participated in evaluating the psychometric properties of the HOS-K. Psychometric analyses consisted of assessing for the following: (1) floor/ceiling effects, (2) internal consistency Electronic supplementary material The online version of this article (doi:10.1007/s00167-014-2946-0) contains supplementary material, which is available to authorized users. Y.-K. Lee K.-H. Koo Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea Y.-C. Ha (&) Department of Orthopaedic Surgery, College of Medicine, Chung-Ang University, 224-1 Heukseok-dong, Dongjak-gu, Seoul 156-755, South Korea e-mail: [email protected] R. L. Martin Department of Physical Therapy, Duquesne University, UPMC Center for Sports Medicine, Pittsburgh, PA, USA D.-S. Hwang Department of Orthopedic Surgery, School of Medicine, Chungnam National University, 33 Munhwa-ro, Jung-gu, Taejon 301-721, South Korea
using Cronbach’s alpha, (3) test–retest reliability over 2–3 weeks with intraclass correlation coefficient (ICC), (4) convergent validity by correlation with the SF-36 and Hip disability and Osteoarthritis Outcome Score (HOOS), (5) construct validity by assessing for a difference in HOS-K scores based on a rating of hip function, and (6) responsiveness with a change in score over a 6-month period. Results The English version of the HOS was translated and adapted to Korean without notable discrepancies. The HOS-K scores were reliable with ICC of 0.946 for the activities of daily living (ADL) subscale and 0.929 for the sports subscale. Internal consistency was confirmed by Cronbach’s alpha [0.90 for both subscales. Both subscales had a strong correlation to the five subscales of SF-36, except the general health subscale. The ADL subscale showed strong correlations with all the subscales of the HOOS, and sports subscale showed strong correlations with all subscales of the HOOS, except the symptom subscales of HOOS. The HOS-K also demonstrated evidence for responsiveness without floor and ceiling effects. Conclusion The HOS-K can be recommended as an outcome instrument in hip arthroscopy for Korean-speaking individuals. Surgeons can use the HOS-K to evaluate the outcome of hip arthroscopy in Korea. Level of evidence Therapeutic case series with no comparison group, Level IV. Keywords Hip Outcome Score Reliability Validity Responsiveness Transcultural adaptation
Introduction The Hip Outcome Score (HOS) was developed specifically to evaluate the clinical outcomes for hip arthroscopy in
123
Knee Surg Sports Traumatol Arthrosc
English-speaking patients [11]. The HOS has been widely used in research [10, 16, 19] and had evidence of its reliability, validity, and responsiveness to support its use [12, 13, 19]. For a wider application of such assessment tools and questionnaires, translation and transcultural adaptation from its original version is necessary. In addition, international guidelines suggest that the transculturally adapted version be tested in terms of psychometric properties [1]. Hip arthroscopy is a well-established surgical option for the treatment of intraarticular pathology, such as femoroacetabular impingement and labral tears, and it is one of the most commonly performed orthopaedic surgical procedures in the Asian countries [3, 4, 18]. Currently, there is a lack of evidence to support the use of a questionnaire to assess outcomes for Korean-speaking individuals after hip arthroscopy. The information acquired from an outcome questionnaire is useful only if there is evidence to support interpretation of the obtained scores. Although the HOS is used worldwide and has been translated into different languages [16], no study has evaluated the HOS in an Asian population. Furthermore, there is no Korean version of the HOS. The aim of this study was to translate and adapt the HOS questionnaire into the Korean language and test the psychometric properties of the Korean version of HOS (HOSK), in terms of reliability, validity, and responsiveness.
Materials and methods Translation and transcultural adaptation from English to Korean was conducted according to the standardized international recommendations [1]. Similar procedures have been successfully completed with other instruments [8, 9]. The study was divided into two parts: (1) translation and transcultural adaptation of the English version of the HOS instrument into the Korean language and (2) testing of the psychometric properties of the HOS-K in patients planning to undergo hip arthroscopy. Based on recommendations by Beaton et al [1], 60 adult patients (34 men and 26 women; median age 37 years, and range 16–80 years) planning to undergo hip arthroscopy in two hospitals between June 2011 and February 2012 were enroled to test the psychometric properties of the HOS-K. The diagnosis for these individuals was labral tear (n = 39), FAI (n = 19) and snapping hip (n = 2). Translation and transcultural adaptation Forward translation and reconciliation were done by two individuals (native Korean speakers fluent in English; one orthopaedic surgeon, and one non-orthopaedic translator) who independently translated the English version of HOS
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into Korean. At a consensus meeting attended by the two translators who performed the forward translation, and three orthopaedic surgeons (YKL, YCH, and KHK), a single Korean version was obtained by reconciling these two Korean versions. The reconciled Korean version was then translated back into English by two bilingual native English speakers, who were both Korean-Americans fluent in Korean (one a medical personnel and the other a nonmedical personnel) and were blinded to the original English version. To assess for harmonization, the back-translated and original versions of the HOS were reviewed by a consensus committee, which included the two translators, three orthopaedic surgeons, one medical personnel, and a research assistant specialized in orthopaedic scoring systems. Each committee member independently compared the back-translated and original HOS versions on an itemby-item basis and scored the equivalence with the originals semantically, idiomatically, experientially, and conceptually [1], as follows: ‘‘not equivalent at all’’ (0), ‘‘mildly equivalent’’ (1), ‘‘moderately equivalent’’ (2), ‘‘nearly equivalent’’ (3), and ‘‘totally equivalent’’ (4) [8, 9]. After averaging the individual item scores, the translated Korean expressions for the items with an average equivalence score of less than 3 (nearly equivalent) were discussed and revised to establish the final version of the HOS-K. During the harmonization process for transcultural adaptation, the average of the transcultural equivalence scores was less than 3 (nearly equivalent) in two items (‘‘running one mile’’ and ‘‘cutting/lateral movements’’ of the sports subscales). During the discussion of these two items, the committee checked that the translation was comprehensive and confirmed the transcultural equivalence of the original English and final Korean versions. The final HOS-K was pretested by 20 Korean outpatients visiting the Department of Orthopedic Surgery at our hospital. The patients completed the questionnaire and were then interviewed for a complete comprehension and to identify any possible difficulties in completing the HOS-K. Psychometric evidence Once enroled in the study, all subjects completed the HOS-K. Two to three weeks later, at the time of hospital admission for surgery, subjects completed the HOS-K again to evaluate test–retest reliability. This time, the subjects did not receive any intervention. Subjects then underwent hip arthroscopy and completed the HOS-K 6 months after their surgery. At the second administration of the HOS-K (2–3 weeks interval), subjects also completed the Korean version of Short Form-36 (SF-36) [6], the Korean version of Hip disability and Osteoarthritis Outcome Score (HOOS) [8], and a rating of overall hip
Knee Surg Sports Traumatol Arthrosc
function (normal, nearly normal, abnormal, or severely abnormal) to evaluate convergent and construct validities. The SF-36 is a valid and reliable generic health status questionnaire containing eight subscales: physical function (PF), role limitations because of physical problems (RP), bodily pain (BP), general health perception (GH), vitality (V), social function (SF), role limitations because of emotional problems (RE), and mental health (MH) [21]. The Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire was a hip-specific questionnaire, which was developed as an extension of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire to provide improved validity for young and active patients with high physical function demands [2, 7, 17]. The HOOS includes five subscales, i.e. symptoms, pain, activity of daily living (ADL), sports/ recreation, and quality of life (QoL). This study was approved by the institutional review board of our hospital (Seoul National University Bundang Hospital, B-1003-095-001), and written informed consent was obtained from all patients.
validity, the correlation between the HOS-K and all HOOS subscales and the subscales of the SF-36 questionnaire was tested using the Spearman’s rank correlation. A Spearman’s rho of [0.50, 0.35–0.50, and \0.35 was considered strong, moderate, and weak correlations, respectively [22]. Construct validity was assessed with hypothesis testing to determine whether the HOS-K would perform as expected with significantly different scores based on the category of an overall rating of hip function. Differential ability for individuals with different status was tested by one-way analysis of variance (ANOVA) and post hoc analysis. The responsiveness, which is a measure of the changes that occur in an individual over a period of time, was evaluated by comparing the pre-arthroscopy and 6-month post-arthroscopy results of the HOS, as determined by using the Wilcoxon signed-rank test. Statistical analysis was performed using SPSS version 15.0 (SPSS, Chicago, IL), and p values of \0.05 were considered significant.
Results Statistical analysis Translation and transcultural adaptation Floor and ceiling effects, the internal consistency, test– retest reliability, convergent validity, construct validity, and responsiveness were evaluated to test the psychometric properties of the HOS-K. The scores from the initial administration of the HOS-K were used to asses for floor and ceiling effects and internal consistency. The proportion of individuals who achieved the highest and lowest possible score was calculated to determine floor and ceiling effects. Floor and ceiling effects were considered present when more than 15 % of the respondents reached the highest or lowest possible score [14]. The internal consistency, which is the degree of homogeneity of the items within each subscale, was assessed using Cronbach’s alpha coefficient. A Cronbach’s alpha coefficient of ]0.7 was considered satisfactory [5]. The test–retest reliability was assed using the scores obtained initially and those obtained 2–3 weeks later. Three weeks was considered long enough to prevent recall, but sufficiently short to ensure that the hip status would not change significantly [15]. Test–retest reliability is the stability across repeated measures and was evaluated using the intraclass correlation coefficient (ICC) (two-way random effect model, assuming a single measurement and absolute agreement) with 95 % confidence intervals. An ICC of[0.70 was considered to indicate good reliability [8]. The convergent validity, which is a type of construct validity, suggests that the value of one parameter would have a quantitative relationship with another similar value of a different parameter. To measure the convergent
During the harmonization process for transcultural adaptation, two items (‘‘running one mile’’ and ‘‘cutting/lateral movements’’) had an average transcultural equivalence score of less than 3 (nearly equivalent). During the discussion of these items, the consensus committee checked that the translation was comprehensive, and a liberal translation was necessary. The committee confirmed the transcultural equivalence of the original English and final Korean versions (supplementary material). Test of the psychometric properties of the final Korean version of the HOS All 60 patients completed the questionnaire for assessment of internal consistency. All 60 patients were admitted for hip arthroscopy and completed the second HOS questionnaire for assessment of test–retest reliability. At this time, all 60 subjects also completed the SF-36, HOOS, and a rating of overall hip function for assessment of validity (Table 1). The final HOS-K was completed by 52 subjects for an assessment of responsiveness 6 months post-operatively (Table 3). No floor or ceiling effect was observed. Cronbach’s alpha was 0.948 in ADL subscale and 0.958 in sports subscale, indicating no heterogeneity. The test–retest reliability was confirmed with an ICC of 0.946 (95 % CI 0.905–0.969) in ADL subscale and 0.929 (95 % CI 0.877–0.959) in sports subscale.
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Knee Surg Sports Traumatol Arthrosc Table 1 Convergent validity of Korean HOS (n = 60)
Score (mean ± SD)
ADL subscale of HOS
70.5 ± 18.7
Sports subscale of HOS
50.1 ± 28.2
Correlation with sports subscale
Spearman R
Spearman R
p value
p value
SF-36 PF
36.7 ± 10.7
0.685
\0.001
0.646
\0.001
SF-36 RP
35.9 ± 12.4
0.574
\0.001
0.718
\0.001
SF-36 BP
39.4 ± 10.6
0.585
\0.001
0.623
\0.001
SF-36 GH
42.0 ± 7.6
0.129
n.s.
0.121
n.s.
SF-36 VT SF-36 SF
45.0 ± 11.1 38.3 ± 12.6
0.446 0.518
0.006 0.001
0.440 0.672
0.006 \0.001 \0.001
SF-36 RE
33.5 ± 15.3
0.522
0.001
0.665
SF-36 MH
41.8 ± 10.3
0.426
0.010
0.351
0.036
HOOS symptom
64.7 ± 19.6
0.569
\0.001
0.385
0.020
HOOS pain
64.7 ± 22.2
0.649
\0.001
0.545
\0.001
HOOS ADL
68.0 ± 21.5
0.784
\0.001
0.620
\0.001
HOOS Sports
54.1 ± 22.5
0.762
\0.001
0.593
\0.001
HOOS QoL
38.5 ± 24.0
0.589
\0.001
0.568
\0.001
HOOS total
63.4 ± 19.5
0.684
\0.001
0.529
0.001
Table 2 Mean Korean HOS according to rating of overall hip function ADL (mean ± SD)
Table 3 Responsiveness of the Korean HOS
Sports (mean ± SD)
Normal
97.5 ± 3.5
97.5 ± 3.5
Nearly normal
78.7 ± 4.7
69.5 ± 13.9
Abnormal
69.3 ± 13.8
47.5 ± 16.1
Severely abnormal
15.0 ± 7.1
17.5 ± 3.5
The convergent validity for the HOS was observed by the strong correlations between the ADL and sports subscale of HOS scores and the five relevant SF-36 subscales, including the PF, RP, BP, SF, and RE. The general health subscale was the subscale that did not correlate with the ADL and sports activity subscale of HOS (n.s) (Table 1). In terms of the convergent validity with the HOOS, all subscales of the HOOS showed strong correlations with the ADL subscale of HOS scores. All subscales of the HOOS showed strong correlations with the sports subscale of HOS scores, except the symptom subscales of HOOS (Table 1). Overall hip function of patients was rated as normal in 2 patients (3.3 %), nearly normal in 20 (33.3 %), abnormal in 36 (60 %), and severely abnormal in 2 (3.3 %). One-way ANOVA and post hoc comparison showed that the scores for patients were significantly different from one another for both ADL and sports subscales (p \ 0.05), except those between patients rating their hip function as normal and those rating it as nearly normal (Table 2). For the responsiveness, each item of the HOS score improved significantly after hip arthroscopy (Table 3).
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Correlation with ADL subscale
ADL subscale Sports subscale
Preoperative score (mean ± SD)
Post-operative score (mean ± SD)
p value
70.5 ± 18.7
78.6 ± 12.8
0.006
50.1 ± 28.2
65.6 ± 28.6
0.001
Discussion The most important finding of the present study was that the transculturally adapted Korean version of HOS was a reliable, valid, and responsive questionnaire without floor and ceiling effects. These results are similar to those found in other language version of the HOS [12, 16]. The HOS-K can be recommended as an outcome instrument in hip arthroscopy for Korean-speaking individuals. The HOOS and Oxford hip score are hip-specific instruments that have been translated into Korean [8, 9]. However, systematic reviews found the HOS to have the most robust evidence and to be the best available outcome questionnaire for evaluating hip arthroscopy [10, 19, 20]. Evidence of its reliability, validity, and responsiveness is available for the original English HOS [11–13] as well as the German version (HOS-D) [16]. Similar to the results of this study of the HOS-K, the English HOS and HOS-D also correlated appropriately to generic outcome measures [12, 16], with HOS-D also correlating to scores on hip-specific measures [16]. Related to evidence for responsiveness,
Knee Surg Sports Traumatol Arthrosc Table 4 Comparison with other language version of HOS HOS ADL
HOS-D Sports
ADL
HOS-K Sports
ADL
Sports
Internal consistency
0.96
0.95
0.95
0.91
0.948
0.958
Test–retest reliability
0.98
0.92
0.94
0.89
0.946
0.929
Scores according to reported level of function Normal 96 94 96.6 95.3 Nearly normal
89
78
83.8
64
97.5
97.5
78.7
69.5
Abnormal
64
40
66.7
41.1
69.3
47.5
Severely abnormal
31
6
62.1
34.3
15
17.5
significant differences between pre- and post-operative scores were noted for both the English HOS and HOS-K [13]. Similar results were also found when defining internal consistency, test–retest reliability, and ability to differentiate individuals based on reported levels of function when comparing the English HOS, HOS-D, and HOS-K [11–13, 16] (Table 4). The most noticeable difference between the three instruments was the scores obtained from those with severely abnormal function. The higher scores obtained for the HOS-D may be attributed to a younger groups of subjects (mean age 33 years) used in the study [16]. The mean ages of the subjects in this study of the HOS-K and the study providing similar evidence for English HOS were 38.4 and 44.2 years, respectively [12]. During the translation and transcultural adaptation process, a careful discussion of some items was required to ensure that their meanings were retained accurately. Since many Koreans cannot understand the anatomic term ‘‘hip’’, as they use other terms, corresponding to the groin, inguinal, buttocks, and thigh to indicate the hips, a sentence defining the anatomic term ‘‘hip’’ was added to the header of the HOS-K, as has been done elsewhere [8, 9]. In addition, Korean culture differs substantially from that in the West, particularly in terms of length unit. Although the term ‘‘running one mile’’ appears in the original HOS, unlike the West, many Koreans do not use the imperial unit system (mile), but rather use the metric unit system (kilometre). We changed ‘‘running one mile’’ to ‘‘running 1 to 2 km’’. The term ‘‘cutting/lateral movements’’ appears in the original HOS. However, unlike the West, many Asian people interpret ‘‘cutting’’ as ‘‘sever’’. Therefore, we used Korean wordings that mean ‘‘block the way’’, instead of ‘‘cutting’’. All these crosslanguage and transcultural issues were addressed and discussed to achieve consensus. This study has limitations. First, this study was conducted in Korea, and thus, caution should be exercised when making generalizations in other Asian countries.
Second, we included the small number of patients with extraarticular pathology such as snapping hip. The results of this research offer evidence to support the use of the HOS-K in hip arthroscopy for Korean-speaking individuals. This study shows that the HOS is a relevant questionnaire in the Eastern as well as in the Western populations, after carrying out the required transcultural adaptation process. In the present study, HOS was translated and adapted transculturally into the Korean language according to the international guidelines. Furthermore, the HOS-K demonstrated relevant internal consistency, reliability, convergent validity, construct validity, and responsiveness, which was comparable to versions written in different languages. Physicians can therefore use the HOS-K to evaluate the outcome of hip arthroscopy in Korea.
Conclusion This study has demonstrated that the Korean version of HOS translated according to the international guidelines was a reliable, valid, and responsive questionnaire without floor and ceiling effects.
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