Cross-cultural adaptation and validation of Singapore English and Chinese Versions of the Oxford Knee Score (OKS) in knee osteoarthritis patients undergoing total knee replacement

OBJECTIVE: To cross-culturally adapt and validate Singapore English and Chinese versions of the Oxford Knee Score (OKS) in patients with knee osteoarthritis (OA) undergoing total knee replacement (TKR) surgery. METHODS: Singapore English and Chinese OKS versions were cross-culturally adapted from the source English version following standard guidelines (including cognitive debriefing), and validated by interviewing patients in English or Chinese using an identical, pretested questionnaire containing the OKS, Short Form 36, and EQ-5D. Reliability was assessed using Cronbach's alpha, dimensionality using principal component factor analysis and item-total correlations, convergent and divergent construct validity by assessing six and three a priori hypotheses, respectively. RESULTS: The Singapore English and Chinese OKS were well accepted by patients in pilot testing. When administered to a consecutive sample of 127 English and 131 Chinese-speaking Singaporeans with knee OA (mean age 66 years, 83% female, mean duration of OA 6 years, Chinese:Malay:Indian:Others=78:7.9:11:3.1% for English version), Cronbach's alpha exceeded 0.8 and factor analysis yielded three factors for both versions. Hypothesized item-total correlations (Spearman's rho > or = 0.4) were observed for all items except limping, kneeling, and night knee pain in both versions. Convergent construct validity was supported by the presence of hypothesized moderate/strong correlations (rho=0.37-0.73) for six and five a priori hypotheses in English and Chinese versions, respectively. Divergent construct validity was supported by the presence of weak correlations (rho=0.09-0.30) for all three a priori hypotheses in both versions. CONCLUSION: Singapore English and Chinese OKS demonstrated good patient acceptability and psychometric properties (including construct validity) among multiethnic Asian patients with knee OA undergoing TKR.     

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

OBJECTIVE: To cross-culturally adapt and validate Singapore English and Chinese versions of the Lequesne Algofunctional Index of knee in patients with knee osteoarthritis (OA) in Singapore. METHODS: Singapore English and Chinese versions were cross-culturally adapted from the source English version following standard guideline (including cognitive debriefing). Patients were asked to complete an identical, pretested questionnaire containing the Lequesne index, Short Form 36 Health Survey (SF-36), and EQ-5D twice within 6 days. Reliability was assessed using Cronbach's alpha and intraclass correlation coefficients (ICC). Dimensionality was assessed by principal component factor analysis. Construct validity was tested by item-to-scale correlations and 12 and six a priori hypotheses for convergent and divergent construct validities, respectively. RESULTS: Singapore English and Chinese Lequesne indices were well accepted by patients in pilot testing and were therefore administered to a consecutive sample of 127 English- and 131 Chinese-speaking Singaporeans with knee OA. Acceptable internal consistency was observed for activities of daily living and the global index (alpha=0.72-0.82), and the good test-retest reliability for all scales in both versions (ICC=0.66-0.94). Expected item-to-scale correlations were presented only in activities of daily living in both versions. Factor analysis yielded two factors for both versions. Convergent and divergent construct validities were supported by the presence of hypothesized correlations between the Lequesne index and SF-36 and EQ-5D scales. CONCLUSION: Both versions of the Lequesne index demonstrated acceptable reliability and validity among multiethnic Asian patients with knee OA, which suggests that it could be used as a global index in the health-related quality of life (HRQoL) measurements in Singapore and possibly other Asian countries.     

Validation of the Western Ontario and Mcmaster University osteoarthritis index in Asians with osteoarthritis in Singapore

OBJECTIVE: To assess the reliability and validity of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) as an outcome measure in Asian patients with knee or hip osteoarthritis (OA) in Singapore. DESIGN: The WOMAC was administered twice 7 days apart to 66 consecutive English-speaking Chinese, Malay or Indian inpatients and outpatients with knee or hip OA seen at a tertiary referral centre through a structured interview, which also assessed demographic and other characteristics. Internal consistency was assessed using Cronbach's alpha, reliability using Spearman's correlations, intraclass correlations and repeatability coefficients, and relationships between WOMAC domains and known determinants of function using Spearman's correlations and the Mann-Whitney U-test. RESULTS: The WOMAC showed good internal consistency (alpha=0.70 to 0.93) and good reliability, with intraclass correlations of 0.83 to 0.90 and mean test-retest score differences of 0.02 to 0.13 points (possible range 4 points). Results of Likert scoring assessment supported the validity of the WOMAC when interpreted in the context of the close association between pain and physical function. Eight of nine a priori hypotheses relating WOMAC Pain and Physical Function scores to known determinants of function were present, supporting construct validity of this scale. CONCLUSION: The WOMAC is a valid and reliable outcome measure in Asian patients with OA in Singapore.     

Cross-cultural adaptation and validation of the French version of the Knee injury and Osteoarthritis Outcome Score (KOOS) in knee osteoarthritis patients

OBJECTIVE: To adapt the Knee injury and Osteoarthritis Outcome Score (KOOS) into French and to evaluate the psychometric properties of this new version. METHODS: The French version of the KOOS was developed according to cross-cultural guidelines by using the "translation-back translation" method to ensure content validity. KOOS data were then obtained in patients with symptomatic knee osteoarthritis (OA). The translated questionnaire was evaluated in two knee OA population groups, one with no indication for joint replacement (medicine), and the other waiting for joint replacement (surgery). The psychometric properties evaluated were feasibility: percentage of responses, floor and ceiling effects; construct validity: internal consistency using Cronbach's alpha, correlations with osteoarthritis knee and hip quality of life domains using Spearman's rank test, and known group comparison between medicine and surgery groups; reliability: intra-class correlation coefficient (ICC), Bland and Altman representation; responsiveness using data obtained prior to and 3 months after surgery: standardized response mean (SRM), and effect size. RESULTS: Thirty-seven patients were included in the medicine group (68% women, mean age=70+/-10 years) and 30 in the surgery group (73% women, mean age=71+/-10 years). The percentage of responses was excellent. Neither a floor nor a ceiling effect was observed, except for the sport and recreation subscale (20.6% of patients with the worst possible score in the medicine group, 40 and 0% in the surgery group prior to and after surgery, respectively). Results for internal consistency (Cronbach's alpha ranging from 0.76 to 0.93), and convergent and divergent construct validity were satisfactory. The patients waiting for knee surgery presented with significantly lower scores in all KOOS domains. The reproducibility of measurements of all KOOS subscales was good to excellent, with ICC ranging from 0.755 to 0.914. The responsiveness was high, with SRM ranging from 0.89 to 1.93, and effect size from 1.31 to 2.8. CONCLUSION: The French version of KOOS is a valid, reliable, and responsive instrument to capture specific aspects of functional disability affecting quality of life of knee OA patients.     

Development and preliminary psychometric testing of a new OA pain measure--an OARSI/OMERACT initiative

OBJECTIVE: To evaluate the measurement properties of a new osteoarthritis (OA) pain measure. METHODS: The new tool, comprised of 12 questions on constant vs intermittent pain was administered by phone to 100 subjects aged 40+ years with hip or knee OA, followed by three global hip/knee questions, the Western Ontario and McMaster Universities (WOMAC) pain subscale, the symptom subscales of the Hip Disability and OA Outcome Score (HOOS) or Knee Injury and OA Outcome Score (KOOS), and the limitation dimension of the Late Life Function and Disability Instrument (LLFDI). Test-retest reliability was assessed by re-administration after 48-96h. Item response distributions, inter-item correlations, item-total correlations and Cronbach's alpha were assessed. Principle component analysis was performed and test-retest reliability was assessed by intra-class correlation coefficient (ICC). RESULTS: There was good distribution of response options across all items. The mean intensity was higher for intermittent vs constant pain, indicating subjects could distinguish the two concepts. Inter-item correlations ranged from 0.37 to 0.76 indicating no item redundancy. One item, predictability of pain, was removed from subsequent analyses as correlations with other items and item-total correlations were low. The 11-item scale had a corrected inter-item correlation range of 0.54-0.81 with Cronbach's alpha of 0.93 for the combined sample. Principle components analysis demonstrated factorial complexity. As such, scoring was based on the summing of individual items. Test-retest reliability was excellent (ICC 0.85). The measure was significantly correlated with each of the other measures [Spearman correlations -0.60 (KOOS symptoms) to 0.81 (WOMAC pain scale)], except the LLFDI, where correlations were low. CONCLUSIONS: Preliminary psychometric testing suggests this OA pain measure is reliable and valid.     

Validation of the Spanish Version of the Knee Injury and Osteoarthritis Outcome Score (KOOS) for Elderly Patients With Total Knee Replacement

The purpose of this study was to validate the Knee Injury and Osteoarthritis Outcome Score (KOOS) for elderly patients who undergo total knee replacement (TKR). The validated Spanish versions of the KOOS and Medical Outcomes Study 36‐Item Short‐Form Health Survey (SF‐36) questionnaires were applied to 137 patients (mean age 72.3, SD 7.5 years). Test–retest data were collected with an intermediate period of 1–2 weeks. To evaluate the clinimetric properties of the KOOS, internal consistency (Cronbach's α), reproducibility (intraclass correlation coefficient [ICC]), construct validity (Spearman's correlation), responsiveness (effect sizes [ES], and standardized response mean [SRM]), and floor and ceiling effects (<15%) were assessed. As result, Cronbach's coefficients of the KOOS subscales ranged from 0.78 to 0.93, and ICC from 0.76 to 0.91. Construct validity was supported by the confirmation of the three predefined hypotheses involving expected correlations between KOOS subscale and SF‐36 physical health subscales. Spearman's correlations were strong between KOOS Pain and SF‐36 Bodily Pain (r = 0.81), KOOS Pain and SF‐36 Physical Functioning (r = 0.67), KOOS activities of daily living (ADL) and SF‐36 Bodily Pain (r = 0.69), KOOS ADL and SF‐36 Physical Functioning (r = 0.74), and KOOS Sports/Recreation and SF‐36 Physical Functioning (r = 0.76). Responsiveness at 1 year after TKR was large with the ES ranging from 0.81 to 2.12, and the SRM from 0.70 to 1.91. Floor and ceiling effects were low. In conclusion, the Spanish version of KOOS has successful psychometric characteristics and is a reliable and valid instrument for assessment of patient‐relevant outcomes in elderly patients with advanced OA who undergo TKR. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2157–2162, 2019     

Cross-cultural adaptation and validation of the Japanese Knee Injury and Osteoarthritis Outcome Score (KOOS)

Background

In Japan, only few cross-culturally adapted, internationally used orthopaedic patient self-assessed outcome scores are available. In addition, the high incidence of knee osteoarthritis (OA) suggests the need for validated outcome measures such as the widely used Knee Injury and Osteoarthritis Outcome Score (KOOS) for Japanese populations. The purpose of this study was to provide a cross-culturally adapted and validated KOOS questionnaire for further use in national and international clinical projects involving Japanese patients.

Methods

The Japanese KOOS was developed according to the standard cross-cultural adaptation guidelines. For validation, the KOOS was tested on 58 patients diagnosed with OA. Reliability was tested using the intraclass correlation coefficient (ICC). Internal consistency or homogeneity was assessed using Cronbach’s alpha. Construct validity was evaluated by quantifying the correlation between the KOOS and the Japanese OKS and SF-36 questionnaires with Spearmann’s correlation coefficients.

Results

No major difficulties were encountered during the translation and pre-testing stages. All five KOOS subscales showed adequate reproducibility with ICC values greater than 0.85, high internal consistency with Cronbach’s alpha values around 0.90, and high Spearmann’s coefficients over 0.50 signifying good correlation between the KOOS subscales and the OKS as well as the majority of the established subscales of the SF-36. No floor and ceiling effects were observed for the five subscales.

Conclusions

Our validated Japanese KOOS is a reliable and stable outcomes measure that provides a valuable basis for national and international clinical projects focusing on patient-based assessments in knee OA.

     

Assessment of the test-retest reliability and construct validity of a modified Lequesne index in knee osteoarthritis

OBJECTIVES: To assess the test-retest reliability and the construct validity of a modified version of the Lequesne index. METHODS: Patients with symptomatic knee osteoarthritis (OA) fulfilling the revised criteria of the American College of Rheumatology completed the Lequesne index twice at a 3-h interval. Impairment outcome measures and patients' perceived discomfort in walking and handicap were recorded. An item-by-item analysis was performed. Items having insufficient psychometric properties were excluded. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC) and the Bland and Altman method. Construct validity was investigated using Spearman rank correlation coefficient and a factor analysis was performed. RESULTS: Eighty-eight patients were included. One question assessing pain (question IE) had a weak reliability (Kappa (kappa) = 0.39) and was excluded. The test-retest reliability of the modified questionnaire was excellent (ICC = 0.95). Expected convergent and divergent correlations were achieved except for visual analog scale pain (VAS P) and VAS handicap (VAS H) (0.46 and 0.40, respectively), and the "a priori" double stratification was confirmed by factor analysis, explaining 48.7% of the variance. CONCLUSION: The modified form of the Lequesne index has sufficient psychometric properties to be used to assess pain and function in knee OA in a French population.     

Accuracy and Validity of Computer Adaptive Testing for Outcome Assessment in Patients Undergoing Total Knee Arthroplasty

BackgroundComputerized adaptive test (CAT) questionnaires may allow standardization of patient-reported outcome measures and reductions in questionnaire burden. We evaluated the validity, accuracy, and efficacy of a CAT system in patients with end-stage osteoarthritis undergoing total knee arthroplasty.MethodsCAT Knee Osteoarthritis Outcome Scores (KOOS) and CAT KOOS-JR questionnaires were applied to 1871 standard form KOOS and 1493 KOOS-JR patient responses, respectively. Mean, standard deviations, Pearson’s correlation coefficients, interclass correlation coefficients (ICCs), frequency distribution plots, and Bland-Altman plots were used to compare the precision, validity, and accuracy between CAT scores and full-form scores.ResultsThere was a mean reduction of 14 questions (33%) in the CAT KOOS and 1.4 questions (20%) with the CAT KOOS-JR version, compared with the standard KOOS and KOOS-JR surveys, respectively. There were no significant differences between KOOS and CAT KOOS scores with respect to pain (P = .66), symptoms (P = .43), quality of life (P = .99), activities of daily living (P = .68), and sports (P = .84). Similarly, there were no significant differences between the standard form KOOS-JR and CAT KOOS-JR scores (P = .94). There were strong correlations with minimal variability between the CAT KOOS and standard KOOS questionnaires for pain (r = 0.98, ICC: 0.98), symptoms (r = 0.97, ICC: 0.97), quality of life scores (r = 0.99, ICC: 0.99), activities of daily living scores (r = 0.99, ICC: 0.99), and sports scores (r = 0.99, ICC: 0.99). Similarly, there were strong correlations between the KOOS-JR and the CAT KOOS-JR scores (r = 0.99, ICC: 0.99).ConclusionCAT KOOS and the CAT KOOS-JR versions are accurate and reduce questionnaire burden up to one-third compared with standard surveys. CAT versions may improve patient compliance and decrease fatigue.     

简体中文版King健康问卷在膀胱过度活动症患者中应用的信度和效度分析

目的 评价简体中文版King健康问卷(KHQ)在膀胱过度活动症(OAB)患者中应用的信度和效度.方法 采用"WHO-QOL跨文化生活质量研究问卷翻译法"将英文版KHQ翻译成简体中文,随机抽取就诊于泌尿外科门诊的OAB患者,在第0周和第2周对其进行2次简体中文版KHQ问卷调查.通过Cronbach's α系数评价问卷的内部一致性;用组内相关系数(ICC)评价重测信度;计算各问题得分与所属领域得分的Spearman等级相关系数(rs)评价内容效度;用因子分析评价结构效度.结果 48例符合纳入标准的OAB患者参与本研究,40例完成2次调查,男7例,女33例,年龄(49.6±14.3)岁.KHQ各亚量表和各领域均具有较好的内部一致性(Cronbach's α:0.7l8～0.924)、中到高的重测信度(ICC:0.567～0.995,P<0.01)以及中到高的内容效度(r:0.462～0.964,P<0.01).因子分析法显示简体中文版KHQ具有可接受的结构效度.结论简体中文版KHQ具有较好的信度和效度,可作为评估OAB患者生活质量的专用量表.     

Cultural adaptation and validation of a German version of the Arthritis Impact Measurement Scales (AIMS2)

OBJECTIVE: To validate a translated and culturally adapted version of the Arthritis Impact Measurement Scale (AIMS) 2 in primary care patients with osteoarthritis (OA) of the hip and knee. METHOD: The AIMS2 was translated into German and culturally adapted. The questionnaire then was administered to 220 primary care patients with OA of the knee or hip. Two hundred and nine questionnaires were returned and analysed. Test-retest reliability was tested in 50 randomly selected patients, of those 42 completed the questionnaire after 2 weeks for a second time. RESULTS: Item-scale correlations were reasonably good as well as the discriminative power of separate scales. The assessment of internal consistency reliability also revealed satisfactory values; Cronbach's alpha was 0.77 or higher for all scales. The test-retest reliability, estimated in an intraclass correlation coefficient (ICC), exceeded 0.90, except the "social activities" scale (0.87). Since only patients with OA of the lower limb were enrolled, substantial floor effects occurred in the "arm function" (28.2%) and the "hand and finger function" scale (29.2%). The principal factor analysis confirmed the postulated three-factor structure with a physical, physiological and social dimension, explaining 48.5%, 13.9% and 6.8% of the variation, respectively. External validity was assessed by calculating correlations to the Western Ontario and MacMaster (WOMAC) osteoarthritis questionnaire a pain visual analogue scale (VAS) and the Kellgren score as well as to disease duration. Spearman's "R" achieved satisfactory values for the corresponding WOMAC scales and the pain-VAS. Correlations with disease duration as well as with the radiological grading were low. CONCLUSION: The GERMAN-AIMS2 is a reliable and valid instrument to assess the quality of life (QoL) in primary care patients suffering from OA.     

Reliability and validity of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index in Italian patients with osteoarthritis of the knee

OBJECTIVE: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis (OA) Index is a tested questionnaire to assess symptoms and physical functional disability in patients with OA of the knee and the hip. We adapted the WOMAC for the Italian language and tested its metric properties in 304 patients with symptomatic OA of the knee. METHODS: Three hundred and four consecutive patients, attending 29 rheumatologic outpatient clinic in northern, central, and southern Italy, were asked to answer two disease-specific questionnaires (WOMAC and Lequesne algofunctional index) and one generic instrument (Medical Outcomes Study SF-36 Health Survey-MOS SF-36). A sample of 258 patients was readministered the WOMAC 7-10 days after the first visit and the structured interview, which also assessed demographic and other characteristics. Internal consistency was assessed using Cronbach's alpha, reliability using intraclass correlation coefficients (ICCs), and construct and discriminant validity using Spearman's correlations, Wilcoxon rank sum test, and Kruskal-Wallis test. RESULTS: All WOMAC subscales (pain, stiffness, and physical function) were internally consistent with Cronbach's coefficient alpha of 0.91, 0.81, and 0.84, respectively. Test-retest reliability was satisfactory with ICCs of 0.86, 0.68, and 0.89, respectively. In comparison with the SF-36, the expected correlations were found when comparing items measuring similar constructs, supporting the concepts of convergent construct validity. Very high correlations were also obtained between WOMAC scores and Lequesne OA algofunctional index. WOMAC physical function, but not WOMAC stiffness and pain subscales, was weakly associated with radiological OA severity (P=0.03). Also, WOMAC pain score was inversely correlated (P=0.01) with years of formal education. Examination of discriminant validity showed that the scores on the WOMAC and SF-36 followed hypothesized patterns: the WOMAC discriminated better among subjects with varying severity of knee problems, whereas the SF-36 discriminated better among subjects with varying levels of self-reported health status and comorbidity. CONCLUSION: The Italian version of WOMAC is a reliable and valid instrument for evaluating the severity of OA of the knee, with metric properties in agreement with the original, widely used version.     

Algo-functional assessment of knee osteoarthritis: comparison of the test-retest reliability and construct validity of the WOMAC and Lequesne indexes

OBJECTIVE: To assess and compare the test-retest reliability and the construct validity of the Lequesne and the French-Canadian version of the WOMAC indexes. DESIGN: Patients with symptomatic knee osteoarthritis (OA) fulfilling the revised criteria of the American College of Rheumatology completed both the Lequesne and the French-Canadian version of the WOMAC indexes twice at a 3-h interval. Impairment outcome measures, patients' perceived discomfort in walking and handicap were recorded. For both questionnaires, an analysis was performed item by item. Repeatability was assessed using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Construct validity was investigated using the Spearman rank correlation coefficient and a factor analysis was performed. RESULTS: 88 patients were included. Eight questions of the WOMAC section C and one question of the Lequesne index had insufficient psychometric properties. Although repeatability of questionnaires was fair to excellent (0.82, 0.68, 0.74, 0.95 for the WOMAC sections A, B, C and Lequesne index respectively), construct validity could not be demonstrated. Factor analysis of the WOMAC extracted five factors which differed from the a priori triple stratification. Factor analysis of the WOMAC section C extracted two factors explaining 71% of the variance which could not be clinically characterized. For the Lequesne index, expected convergent correlations were not always achieved. Three factors were extracted by factor analysis explaining 58% of the variance. CONCLUSION: Despite their good test-retest reliability, the two composite indexes evaluated are not valid to assess the concept of functional disability induced by knee OA in a French population.     

The effects of knee arthroplasty on walking speed: A meta-analysis

Background

The WOMAC is the most widely used self-report measure to evaluate physical functioning in hip or knee osteoarthritis, however its ability to discriminate pain and physical functioning (i.e. discriminate validity) has repeatedly been questioned. Little to no data is available on the discriminant validity of alternative questionnaires that measure the same construct, for instance the Hip and Knee Osteoarthritis Outcome Score (HOOS and KOOS, respectively) and the Lower Extremity Function Scale (LEFS). Therefore, we translated the LEFS to Dutch and studied its psychometric properties (i.e. validity, reliability and responsiveness). In addition, we assessed the discriminate validity of the LEFS, HOOS and KOOS.

Methods

After translation with a forward/backward protocol, 401 individuals with hip or knee osteoarthritis completed the LEFS, HOOS/KOOS, SF-36, Hospital Anxiety and Depression Scale and Checklist Individual Strength questionnaires. To assess reliability and responsiveness, a sample of 106 and 108 patients completed a comparable set of questionnaires within 3?weeks and 3?months, respectively. Feasibility, validity, reliability and responsiveness were evaluated. Discriminant validity of the LEFS, HOOS and KOOS was examined by contrasting the scales?? correlations with the physical functioning subscale of the SF-36 with the scales?? correlations with the bodily pain subscale of the SF-36.

Results

The Dutch version of the LEFS was feasible, had good internal consistency (0.96), good reliability (ICC?=?0.86), good construct and discriminant validity, and showed no floor or ceiling effects. The minimal detectable change (MDC₉₀) was ten points. Area under the receiver operating characteristic curve (AUC) analyses revealed good (AUC?=?0.76) and fair (AUC?=?0.63) responsiveness for the LEFS in improved and worsened patients, respectively. Discriminant validity for pain was apparent for the LEFS (p?<?0.01), but not for the HOOS and KOOS (p?=?0.21 and p?=?0.20, respectively).

Conclusions

Considering the LEFS?? good psychometric qualities and ability to discriminate between pain and functioning, we recommend the LEFS as the outcome measure of choice to assess self-reported physical functioning in individuals with hip or knee osteoarthritis.     

The Short Form KOOS,JR Is Valid for Revision Knee Arthroplasty

BackgroundThe Knee Injury Osteoarthritis Outcome Survey, Joint Replacement (KOOS, JR) is a reliable, responsive, and validated patient-reported outcome measure (PROM) of knee health in patients with knee osteoarthritis undergoing unilateral primary total knee arthroplasty (TKA). The validity of the KOOS, JR for revision TKA remains unknown.MethodsWe identified 314 patients who underwent revision TKA and had completed preoperative and 2-year postoperative PROMs. Validation included assessment of local dependence, unidimensionality, internal consistency, external construct validity, responsiveness, and floor effects preoperatively and ceiling effects at 2 years postoperatively.ResultsAmong patients undergoing revision TKA, the KOOS, JR demonstrated an absence of residual item correlation, adequate unidimensionality, high internal consistency (Person Separation Index: 0.897), and high external construct validity with existing validated PROMs, including KOOS Pain (Spearman’s correlation coefficient 0.89) and KOOS activities of daily living (0.90) domains. The KOOS, JR was more responsive (standardized response means: 1.14) to revision TKA than other common knee PROMs. Three percent of revision TKA patients were at the floor (lowest score) preoperatively and 9% reached the ceiling (highest possible score) postoperatively.ConclusionsKOOS, JR performs well in revision TKA patients with regard to internal consistency, external validity, responsiveness, and floor and ceiling effects. Our results support extending its use to revision TKA in both clinical and research settings.     

Patient-reported outcome measures for the knee

In the past 20 years, there has been considerable growth in the number of knee instruments and rating scales designed to measure outcomes from the perspective of the patient. Only a few of these instruments have been evaluated for reliability, validity, and responsiveness. The purpose of this systematic review was to examine the psychometric evidence of patient-reported outcome measures for the knee and identify the best scores for specific knee conditions. A literature search was performed to retrieve references relating to the development and evaluation of knee-specific instruments. Twenty-four unique instruments were identified, and most have satisfactory evidence for internal (alpha > or = 0.82) and test-retest reliability (intraclass correlation coefficient > or = 0.80). Face/content validity was typically assessed during the item selection process, and construct validity was evaluated through strict hypothesis testing or correlations with other clinical measures. For many instruments, effect sizes and standardized response means measuring responsiveness were large (> or = 0.80) within disease-specific populations. Based on the psychometric data, recommendations include the Cincinnati Knee Rating System, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm Knee Score for anterior cruciate ligament (ACL) injuries, the Kujala Anterior Knee Pain Scale for anterior knee pain, the International Knee Documentation Committee (IKDC) Subjective Knee Form, KOOS, and Lysholm Knee Score for focal chondral defects, the Western Ontario Meniscal Evaluation Tool (WOMET) for meniscal injuries, and the KOOS for osteoarthritis (OA). Although the IKDC can be used as a general knee measure, no instrument is currently universally applicable across the spectrum of knee disorders and patient groups. Clinicians and researchers looking to use a patient-based score for measurement of outcomes must consider the specific patient population in which it has been evaluated. Using a diagnostic algorithm that measures the anatomic parts of the knee as separate constructs may solve this dilemma, allowing for measurement of treatment outcomes across patient groups and selection of the optimal clinical intervention.     

Reliability, validity, and responsiveness of the Lysholm knee scale for various chondral disorders of the knee

BACKGROUND: The Lysholm knee scale is a condition-specific outcome measure that was originally designed to assess ligament injuries of the knee. The purpose of this study was to determine the psychometric properties of the Lysholm knee scale for various chondral disorders of the knee. METHODS: Test-retest reliability, internal consistency, content validity, criterion validity, construct validity, and responsiveness to change were determined for the Lysholm knee scale within subsets of an overall study population of 1657 patients with chondral disorders of the knee. The study population was a heterogeneous group of patients with various types of traumatic and degenerative chondral lesions, including isolated lesions and those associated with meniscal and ligament injuries. RESULTS: The overall Lysholm knee scale and six of the eight domains had acceptable test-retest reliability (intraclass correlation coefficient = 0.91) and internal consistency (Cronbach alpha = 0.65). The overall Lysholm knee scale demonstrated acceptable floor (0%) and ceiling (0.7%) effects; however, the floor effects for the domain of squatting and the ceiling effects for the domains of limp, instability, support, and locking were unacceptable (>30%). There was acceptable criterion validity with significant (p < 0.05) correlations between the overall Lysholm knee scale and the physical functioning, role-physical, and bodily pain domains of the Short Form-12 scale; the pain, stiffness, and function domains of the Western Ontario and McMaster Universities Osteoarthritis Index; and the Tegner activity scale. The overall Lysholm knee scale had acceptable construct validity, with all nine hypotheses demonstrating significance (p < 0.05), and it had acceptable responsiveness to change (effect size, 1.16; standardized response mean, 1.10), with large effects (> or = 0.80) for the domains of pain, limping, swelling, and squatting and a small effect (> or = 0.20) for the domain of instability. CONCLUSIONS: The Lysholm knee scale demonstrated overall acceptable psychometric performance for outcomes assessment of various chondral disorders of the knee, although some domains demonstrated suboptimal performance. Psychometric testing of other condition-specific knee instruments in patients with chondral disorders of the knee would be helpful to allow for comparison of psychometric properties.     

Cross-cultural adaptation and validation of Korean Western Ontario and McMaster Universities (WOMAC) and Lequesne Osteoarthritis Indices for Clinical Research

OBJECTIVE: Our aims were to translate WOMAC and Lequesne osteoarthritis (OA) indices into Korean (KWOMAC, KLequesne) and confirm their reliability, validity, and responsiveness. DESIGN: The WOMAC and Lequesne indices were translated into Korean by three translators and translated back into English by three different translators. Fifty consecutive patients with OA were asked to rate the comprehensibility of the questions on a 4-point scale. The comprehensibility (responding with 'good' and 'very good') ranged from 78% to 99%. Test-retest was performed in another 47 patients with knee OA. The final 53 patients with knee OA, within the context of a clinical trial of two non-steroidal antiinflammatory drugs for 4 weeks, were studied to assess the internal consistency, construct validity, and responsiveness of the Korean versions. RESULTS: The test-retest reliability of the KWOMAC 3 subscales and the KLequesne yielded intraclass correlation coefficients of 0.79-0.89 and 0.87. The Cronbach standardized alphas were 0.81-0.96 and 0.75, respectively. For the construct validity, the correlation coefficients of both the KWOMAC subscales and the KLequesne with patient pain assessment and patient global assessment were between 0.30 and 0.70 and the KWOMAC subscales correlated with the KLequesne (0.41-0.55). For responsiveness, the KWOMAC and KLequesne scores significantly improved by 4-week post-treatment compared with pre-treatment; effect size values were between 0.41 and 0.69 for the KWOMAC subscales and 0.70 for the KLequesne; and the relative efficiency values of the KWOMAC subscales vs the KLequesne were between 0.87 and 0.90. CONCLUSIONS: The reliability, validity, and responsiveness of the KWOMAC and the KLequesne are confirmed.     

Assessment of the test-retest reliability and construct validity of a modified WOMAC index in knee osteoarthritis

OBJECTIVE: To assess the test-retest reliability and the construct validity of a modified version of the French-Canadian version of the WOMAC index. METHODS: Open prospective study conducted in departments of Rheumatology, Rehabilitation and Orthopedic surgery of a tertiary care teaching hospital. Eighty-eight patients with symptomatic knee osteoarthritis (OA) fulfilling the revised criteria of the American College of Rheumatology were included. The French-Canadian version of the WOMAC index was completed twice at a 3-h interval. Impairment outcome measures, patients' perceived discomfort in walking and handicap were recorded. An item-by-item analysis was performed. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC) and the Bland and Altman method. Construct validity was investigated using the Spearman rank correlation coefficient and a factor analysis was performed. RESULTS: Eight questions assessing function (section C) and the two questions assessing stiffness (section B) had insufficient psychometric properties and were excluded. Although test-retest reliability of the questionnaire was fair to good (0.82, 0.85, for the WOMAC section A, and modified section C, respectively), construct validity could not be demonstrated. Factor analysis of the modified form of the WOMAC extracted four factors, which differed from the a priori stratification. However, factor analysis of the modified section C extracted two factors explaining 68.4% of the variance, which could be clinically characterized. CONCLUSION: Despite its good test-retest reliability, the modified WOMAC index is not valid for assessing pain and disability induced by knee OA in a French population. Section A and modified section C could be used separately to assess, respectively, pain and function.     

Reliability and validity of the National Institutes of Health: Chronic Prostatitis Symptom Index in a Malaysian population

The objective of the study is to determine the short- and long-term utility of the Chinese, Malay and English versions of the National Institutes of Health—Chronic Prostatitis Symptom Index (NIH-CPSI) in our ethnically diverse population. The NIH-CPSI was translated into Chinese and Malay, and then verified by back translation into English. Subjects included 100 new chronic prostatitis/chronic pelvic pain (CP/CPPS) patients, 71 new benign prostatic hyperplasia patients and 97 healthy individuals. Reliability was evaluated with test–retest reproducibility (TR) by calculating intraclass correlation coefficients (ICC). Internal consistency was evaluated by calculating Cronbach’s alpha (α). Validity assessments included discriminant and construct validity. (Presented in the order of Chinese, Malay then English). ICC values for short-term (1 week) TR were 0.90, 0.80 and 0.89, while ICC values for long-term (14 weeks) TR were 0.54, 0.61 and 0.61. Cronbach’s α values were 0.63, 0.62 and 0.57. The NIH-CPSI total score discriminated CP/CPPS patients (P<0.001) from the control groups with receiver operating curve values of 0.95, 0.98 and 0.94, respectively. Construct validity, reflected by the correlation coefficient values between the International Prostate Symptom Score and the NIH-CPSI of CP/CPPS patients were 0.72, 0.49 and 0.63 (all P<0.05). The Chinese, Malay and English versions of the NIH-CPSI each proved effective in our population. Short-term TR and discriminant validity were excellent for all three versions. However, long-term TR was only moderate, which might reflect variation in patients’ perceptions of symptoms over time. Source of Funding: This study was supported, in part, by an unrestricted grant from Abbott Laboratories, Malaysia and the US National Institutes of Health, Bethesda. *Phaik Yeong Cheah was pursuing a doctorate degree at University of Science Malaysia at the time the study was conducted. She is now an employee of Abbott Laboratories Malaysia. This work was presented, in part, at the American Urological Association Meeting, San Francisco, May 8–13, 2004.