Acceptability, reliability, validity and responsiveness of the Turkish version of WOMAC osteoarthritis index

OBJECTIVE: To evaluate the acceptability, reliability, validity and responsiveness of the Turkish version of Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index in physiotherapy outpatient practice in Turkey. METHOD: Data were obtained from 72 patients with OA of the knee. They were asked to answer two disease-specific questionnaires (WOMAC LK 3.1 and Lequesne-Algofunctional Index of Severity for the knee) and one generic instrument (Medical Outcomes study SF-36 Survey-SF-36). Acceptability was assessed in terms of refusal rate, rates of missing responses, and administration time. Reliability was assessed using Cronbach's alpha. Content validity was assessed by examining the floor and ceiling effects, and skew of the distributions. Convergent and divergent validity was assessed by examining the Pearson's correlation coefficients. Responsiveness was determined by examining effect size (ES), standardized response means (SRM) and P values generated using Wilcoxon's test. RESULTS: The overall response rate was 100%. Alpha values for all WOMAC subscales exceeded the value of 0.70 at both baseline and follow-up assessments. Frequency distributions of scores were symmetrical. Subscales had negligible floor and ceiling effects. Both pain and physical function subscales were fairly correlated with the subscales measuring similar constructs of SF-36, whereas they were weakly correlated with other dimensions of SF-36. A good correlation was obtained between WOMAC total and Lequesne index. The pain and physical function subscales of WOMAC index were the most responsive subscales. CONCLUSION: The Turkish WOMAC OA index is acceptable, valid, reliable and responsive for use in Turkish patients with knee 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.     

A comparison of outcomes in osteoarthritis patients undergoing total hip and knee replacement surgery

OBJECTIVE: The aims of this study were to assess changes in physical function and quality of life with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the instrument of the Medical Outcomes Study SF-36 Health Survey (MOS SF-36), respectively, in patients undergoing hip anf knee joint replacement surgery and to compare the responsiveness of these two outcome measures 1 year after surgery. DESIGN: One hundred and ninety-four patients with osteoarthritis (OA knee 108, OA hip 86) admitted to four hospitals in Sydney were followed over a period of 1 year at 3 monthly intervals. RESULTS: WOMAC measures improved significantly after 1 year for OA hip and OA knee: there was reduction in pain of 71% and 53%, reduction of stiffness of 55% and 43% and improvement in physical function of 68% and 43%, respectively. MOS SF-36 measures in those having hip surgery improved significantly for pain (222%), physical function (247%), physical role functioning (402%), general health (110%), vitality (143%0, social functioning (169%) and mental health (114%). For those in the knee surgery group, significant improvement was seen for pain (175%), physical function (197%), physical role functioning (275%), vitality (125%) and social functioning (119%). The WOMAC was a more responsive measure than the MOS SF-36. CONCLUSION: WOMAC and MOS SF-36 detect significant and clinically meaningful changes in outcome after hip and knee replacement. WOMAC requires a smaller sample size and is more responsive in the short term. For a follow-up longer than 6 months MOS SF-36 provides additional information. The improvement in outcomes following hip joint surgery were significantly greater than those following knee surgery.     

Relative efficiency and validity properties of a visual analogue vs a categorical scaled version of the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index: Spanish versions

OBJECTIVE: To compare the performance of visual analogue (VAS) vs categorical (CT) scaled versions of the three subscales (pain, stiffness and difficulty) of the WOMAC Index in patients with knee osteoarthritis. MATERIAL AND METHODS: Patients with knee OA (at least grade II of Kellgren & Lawrence classification) were treated for a 6-weeks period with an NSAID. The following measures were applied at baseline and after treatment: VAS and CT WOMAC scales, Lequesne Index, pain on VAS, and global assessment by patient and observer. Construct Validity was determined by correlation of each of the subscale scores with the other outcomes both at baseline and after treatment (Pearson's test); responsiveness comparing baseline vs final status by Wilcoxon's test; reliability by analysis of the internal consistency using Cronbach's alpha at baseline and after the treatment period; and test-retest reliability by Kendall's Tau-c statistics. Finally, correlation and analysis of the relative efficiency (RE) between the subscales of both formats were tested. RESULTS: Seventy-three (8 men and 65 women) patients with a mean disease duration from first diagnosis of 69 months (3 to 254) completed the study. The following were the observed values for the instruments' psychometric properties: (1) construct validity: correlations ranged from 0.30 to 0.84 for VAS and 0.27 to 0.77 for CT subscales; (2) responsiveness: achieved P values for the pain, stiffness and difficulty scales were P<0.0001, P=0.002 and P<0.0001 in VAS and P=0.003, P<0.0001 and P=0.001 in CT format respectively; (3) internal consistency: the obtained Cronbach's alpha coefficients ranged from 0.71 to 0.97 for the VAS and 0.64 to 0.95 for the CT subscales; (4) test-retest reliability: correlation coefficients ranged from 0.36 to 0.76 for VAS and 0.34 to 0.52 for CT subscales; and (5) the relative efficiency of the subscales in VAS vs CT format were 2.20, 0.91 and 1.91 for pain, stiffness and difficulty respectively. Significant correlations between subscales in both formats ranging from 0.72 to 0.86 were observed. CONCLUSION: We have shown that both the VAS version of WOMAC have adequate evaluative and discriminative properties. We found the pain and physical function scales in VAS format and the stiffness scale in CT format to have a slightly better performance in this sample.     

Clinical evaluation of the WOMAC 3.0 OA Index in numeric rating scale format using a computerized touch screen version

BACKGROUND: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is a previously described self-administered questionnaire covering three domains: pain, stiffness and function. It has been validated in patients with osteoarthritis (OA) of the hip or knee in a paper-based format. AIM: To validate the WOMAC 3.0 using a numerical rating scale in a computerized touch screen format allowing immediate evaluation of the questionnaire. In the computed version cartoons, written and audio instruments were included in order facilitate application. METHODS: Fifty patients, demographically balanced, with radiographically proven primary hip or knee OA completed the classical paper and the new computerized WOMAC version. Subjects were randomized either to paper format or computerized format first to balance possible order effects. RESULTS: The intra-class correlation coefficients for pain, stiffness and function values were 0.915, 0.745 and 0.940, respectively. The Spearman correlation coefficients for pain, stiffness and function were 0.88, 0.77 and 0.87, respectively. CONCLUSION: These data indicate that the computerized WOMAC OA index 3.0 is comparable to the paper WOMAC in all three dimensions. The computerized version would allow physicians to get an immediate result and if present a direct comparison with a previous exam.     

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.     

Disability and quality of life of patients with knee or hip osteoarthritis in the primary care setting and factors associated with general practitioners' indication for prosthetic replacement within 1 year

OBJECTIVE: To assess disability and health-related quality of life (HRQoL) of patients with knee or hip OA in primary care and to determine factors associated with GPs' opinion that their patients will need prosthetic replacement within 1 year after the consultation. METHODS: Design: A cross-sectional national survey. Setting: Primary care in France. Participants: 1471 GPs and 4183 patients with hip or knee OA. Measures: Pain on an 11-point numeric scale (0-10), disability on the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC) (1-100) and Lequesne index (0-24), and quality of life on the Medical Outcomes Study 36-item Short Form (MOS SF-36; 0-100). RESULTS: We analyzed records of 4121 patients (2540 knee, 1581 hip OA). Patients with knee or hip OA exhibited high and similar levels of pain (5.2+/-2.1 and 5.3+/-2.3) and disability (Lequesne score: 12.0+/-4.2 and 11.8+/-4.3; WOMAC score: 45.7+/-19.3 and 45.2+/-17.3) The decrease in HRQoL was similar for patients with either location of the disease. GPs more often considered that their patients with hip OA would need prosthetic replacement within 1 year (28.1%) than those with knee OA (15.8%). Most factors associated with GPs' opinion were identified for both locations of disease and were related to disability and pain levels. CONCLUSIONS: In the primary care setting, patients with knee or hip OA have similar, high disability levels and substantially low HRQoL. Patients' disability seems to play a central role in GPs' opinion of the need for their patients with either type of OA to undergo prosthetic replacement within 1 year.     

Responsiveness of the electronic touch screen WOMAC 3.1 OA Index in a short term clinical trial with rofecoxib

BACKGROUND: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is a self-administered validated questionnaire for patients with osteoarthritis (OA) of the hip or knee. The electronic touch screen version of the WOMAC (e-WOMAC) has been previously shown to be highly correlated with the original paper format. However, whether the e-WOMAC would be suitable for monitoring the effects of drug treatment is unknown. AIM: To validate the longitudinal use of the e-WOMAC questionnaire and its ability to detect changes in WOMAC-scores induced by drug treatment in outpatient care. METHODS: Fifty-three outpatients, men and women (mean age: 64 years; SD+/-9.5), with symptomatic osteoarthritis of hip or knee were included in an open label study with rofecoxib. At three visits over 3 weeks, responsiveness of the WOMAC 3.1 regarding the three subscales, pain, stiffness and function, were compared for the original paper format and the computer touch screen format (QUALITOUCH) using a Likert scale. WOMAC scores were transformed to the 0-100 scale. ANOVA for repeated measures was used for analysis and effect sizes by subscale were compared for both formats. RESULTS: Responsiveness for all three subscales was similar between formats. In both formats, pain and stiffness were significantly reduced with rofecoxib as early as 7 days, while functional ability was significantly increased (P<0.01 for all aggregate subscale scores) with continuing improvement until the end of study. The effect sizes by subscale between Day 1 and 21 were not statistically different between the paper and the electronic version of the questionnaire and showed similar clinically meaningful improvements in WOMAC scores over 3 weeks. CONCLUSION: In this longitudinal intervention study, the e-WOMAC OA Index 3.1 showed similar responsiveness in detecting clinically meaningful changes than the original paper format.     

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.     

Changes in pain, stiffness and physical function in patients with osteoarthritis waiting for hip or knee joint replacement surgery

OBJECTIVE: Little has been reported on changes in health status in patients with osteoarthritis (OA) while waiting for hip or knee replacement surgery. In this study we assessed (1) changes in self-reported pain, stiffness and physical function in patients with OA of the hip or knee, from the decision to undergo surgery to 14 days prior to surgery, and (2) the determinants of these changes. METHODS: Among 353 baseline respondents, 170 waited >30 days for surgery, completed the Western Ontario and McMaster Universities Arthritis Index (WOMAC) before surgery and were included in the analysis of changes; 120 with OA of the hip and 50 of the knee. We analyzed changes in WOMAC scores using the paired t test and determinants of the changes using multiple linear regression. RESULTS: Patients with OA of the hip did not change on any WOMAC scale before surgery. Knee patients deteriorated with time on the WOMAC stiffness and total scales, but not on the pain or physical function subscales. In both patient categories, higher baseline WOMAC scores were associated with smaller changes on all subscales and the total score, and female sex was associated with deterioration on the pain subscale. CONCLUSIONS: Patients with OA of the hip reported no change in pain, stiffness or physical function while waiting for joint replacement surgery, whereas patients with OA of the knee deteriorated on the stiffness and total scales of the WOMAC. This suggests a difference in patient selection, referral pattern or disease development between the patient categories.     

Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials

OBJECTIVE: To evaluate the efficacy of preparations with avocado-soybean unsaponifiables (ASUs) in osteoarthritis (OA) patients using meta-analysis on randomized controlled trials (RCTs). METHOD: RCTs from systematic searches were included if they explicitly stated that hip and/or knee OA patients were randomized to either ASU or placebo. The co-primary outcome was reduction in pain and Lequesne index, leading to effect size (ES), calculated as the standardized mean difference. As secondary analysis, the number of responders to therapy was analyzed as odds ratios (ORs). Restricted maximum likelihood methods were applied for the meta-analyses, using mixed effects models. RESULTS: Four trials--all supported by the manufacturer--were included, with 664 OA patients with either hip (41.4%) or knee (58.6%) OA allocated to either 300 mg ASU (336) or placebo (328). Average trial duration was 6 months (range: 3-12 months). Though based on heterogeneous results, the combined pain reduction favored ASU (I(2) = 83.5%, ES = 0.39 [95% confidence intervals: 0.01-0.76], P=0.04). Applying the Lequesne index also favored ASU (I(2) = 61.0%, ES = 0.45 [0.21-0.70], P = 0.0003). Secondarily, the number of responders following ASU compared to placebo (OR = 2.19, P = 0.007) corresponded to a number needed to treat of six (4-21) patients. CONCLUSIONS: Based on the available evidence, patients may be recommended to give ASU a chance for e.g., 3 months. Meta-analysis data support better chances of success in patients with knee OA than in those with hip OA.     

Health-related quality of life in patients with osteoarthritis after total knee replacement: factors influencing outcomes at 36 months of follow-up

OBJECTIVES: (1) To evaluate health-related quality of life (HRQL) in patients with severe osteoarthritis (OA) undergoing total knee replacement (TKR) and (2) to identify the influence of sociodemographic, clinical, intra-operative and postoperative variables on HRQL at 36 months after TKR. DESIGN: Prospective study with a 36-month follow-up. Preoperative interviews were carried out with 90 in-patients. The disease-specific Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire was used to measure the health status. Sociodemographic, clinical, intra-operative degree of difficulty, in-patient and postoperative data were collected. Associations were analyzed using linear regression models. RESULTS: Of the 90 potentially eligible patients, 67 (54 females, mean age 74.83, standard deviation [SD] 5.57) completed follow-up assessment. There were significant differences between preoperative and postoperative WOMAC pain, stiffness and function scores (P<0.001, P=0.005 and P<0.001, respectively). Variables retained in each of the models explained between 15% and 23% (R(2) adjusted) of the variability of each WOMAC dimension. Higher preoperative WOMAC scores were associated with greater postoperative improvement (P<0.001). Chronic musculoskeletal pain unrelated to knee OA was associated with higher WOMAC pain, stiffness and function dimension scores (P=0.004, P=0.029 and P=0.005, respectively). Severe (Class III) obesity (body mass index [BMI] 35-39.9) was associated with more pain (P=0.049). CONCLUSIONS: In patients with severe OA, HRQL significantly improved at 36 months after TKR, especially in the pain dimension. Lower preoperative WOMAC scores, chronic pain unrelated to knee OA, and severe obesity negatively influenced postoperative WOMAC scores. This disease-specific questionnaire may help to identify patients at increased risk of negative outcomes after surgery.     

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.     

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.     

Responsiveness and clinically important differences for the WOMAC and SF-36 after total knee replacement

OBJECTIVES: To study responsiveness and establish the minimal clinically important differences (MCIDs) and minimal detectable change (MDC) in patients undergoing total knee replacement (TKR) using the Short Form 36 (SF-36) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). METHODS: Prospective observational study in three public hospitals of all consecutive patients on waiting lists to undergo TKR intervention with diagnosis of knee osteoarthritis (OA). Patients were asked to complete before the intervention and at 6 months and 2 years afterward the SF-36 and the WOMAC health-related quality of life questionnaires (HRQoL), and additional transition questions which measured the changes in their joint at 6 months. In both questionnaires the possible range of values is from 0 to 100 points. RESULTS: In WOMAC improvement at 6 months after a TKR was between 27 (stiffness) and 31 points (pain). The SF-36 showed improvements between the 28.3 points of role physical and 2.79 of general health. From 6 months to 2 years, WOMAC improvements were between 2 and 6 points. The MCID ranged from 14.52 (stiffness) to 22.87 (pain) on the WOMAC and in the physical domains of SF-36 from 11.56 (physical function) to 16.86 (bodily pain). On the WOMAC, the MDC ranged from 13.11 (function) to 29.12 (stiffness), and on SF-36 from 19.50 (physical function) to 41.23 (social functioning). CONCLUSIONS: The MCID for TKR is around 15 on WOMAC, while with the SF-36 of at least 10 points. These values should not be considered as absolute thresholds.     

Clinical results 2 years after total hip replacement (WOMAC/SF-36) and comparison with the normal population (SF-36)

AIM: The aim of this study was to determine the outcome after total hip replacement (THR) with the WOMAC and the SF-36 as well as to identify the most responsive items and to elucidate the reasons for increased pain postoperatively. METHODS: 73 patients filled out the questionnaires preoperatively and 3, 6, 12, 24 months postoperatively. All mean subscales and the responsiveness for each question were calculated. The patients with increased pain postoperatively were reassessed. RESULTS: All WOMAC subscales and six of the eight SF-36 subscales showed significant improvements after THR (p < 0.05). The most responsive items were the pain and disability questions (SRM, ES > 1.5). Two patients with a higher pain score postoperatively had associated symptomatic degenerative lumbar spinal disease. CONCLUSIONS: The WOMAC and the SF-36 are valid measures of the outcomes of THR in their German translations and document the good results after THR. Two years after THR the patients reach the same health state compared to an age matched control group in the population. The WOMAC contains more questions of higher responsiveness than the SF-36. A higher pain score postoperatively may be caused by degenerative disease of the lumbar spine.     

Clinimetric properties of the AUSCAN Osteoarthritis Hand Index: an evaluation of reliability,validity and responsiveness

OBJECTIVE: To assess the reliability, validity and responsiveness of the Australian/Canadian (AUSCAN) Osteoarthritis Hand Index in both Likert (LK) and Visual Analogue (VA)-scaled formats. METHODS: Two separate studies were conducted; the first addressing reliability and validity issues and the second addressing index responsiveness. In a group of 50 patients with osteoarthritis (OA) of the hand, test-retest reliability was assessed at a 1-week interval and internal consistency from single administrations of the Index. Construct validity was evaluated against several other outcome measures including the Functional Index for Hand Osteoarthritis (FIHOA), separate patient and physician global assessments, Doyle Index, grip strength, pinch grip, and Health Assessment Questionnaire. A 6-week washout retreatment design was used in a group of 44 OA hand patients to assess index responsiveness and comparative responsiveness against the FIHOA. RESULTS: Reliability and construct validity coefficients confirm the reliability and construct validity of both the AUSCAN LK3.0 and AUSCAN VA3.0 Indices. The washout retreatment study establishes index responsiveness and suggests that the AUSCAN LK3.0 and AUSCAN VA3.0 Indices may be more responsive than the FIHOA. CONCLUSIONS: The patient self-completed AUSCAN LK3.0 and AUSCAN VA3.0 Indices are reliable, valid and responsive and can be recommended as primary outcome measures for future hand OA clinical trials.     

Comparative analysis of patient-centered outcome of total hip and knee arthroplasty

AIM: The aim of the present study was a comparative investigation of the functional improvement reported by patients suffering from primary osteoarthritis of the knee or hip undergoing total joint replacement and assessed at 3 months. METHOD: In a prospective, controlled clinical trial, 56 patients with primary osteoarthritis of the hip and 59 patients with primary osteoarthritis of the knee undergoing total joint replacement were assessed at two measuring times (day of admission = t1 and 3-month follow-up = t2) using the XSMFA-D (Extra Short Musculoskeletal Function Assessment Questionnaire--German version), WOMAC (Western Ontario and McMasters Universities) arthrosis index and FFb-H OA (Function Assessment Questionnaire Hannover Osteoarthritis). The statistical analysis included effect sizes as standardised response mean, t-test and covariance analysis. RESULTS: Both groups of patients demonstrated significant improvements of the musculoskeletal functions measured. The effect sizes between baseline scores and 3-month follow-up scores range from 0.4 to 2.0 and can be considered as large effects. The covariance analysis showed significant differences between patients with osteoarthritis of the hip and knee for almost every score examined. Patients with hip replacement showed large improvements. A significant influence of the presurgery baseline score on the 3-month score was found consistently. Further analysis showed that patients with medium or strong degrees of disability according to the Function index of the XSMFA-D showed the strongest effects of change at 3 months. However, their scores at t2 were less than the scores of the less disabled patients at t1. CONCLUSION: We conclude that patients with hip replacement show more improvement 3 months after the surgery than patients with knee replacement. Furthermore, it was seen that patients who were more disabled before surgery achieved more improvement than the less-disabled patients. However, they did not achieve the level of the less disabled patients. Thus, the recommendation that total joint replacement should be performed as late as possible should be reviewed.     

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.