Validation of the Functional Assessment of Chronic Illness Therapy Fatigue Scale relative to other instrumentation in patients with rheumatoid arthritis. Reliability, validity, and responsiveness of the modified Kapandji index for assessment of functional mobility of the rheumatoid hand. Item Response Theory Methods can Improve the Measurement of Physical Function by Combining the Modified Health Assessment Questionnaire and the SF-36 Physical Function Scale Sensitivity of a health status measure to short-term clinical changes in arthritis. Evaluation of Medical Outcomes Study Short Form-36 Taiwan version in assessing elderly patients with hip fracture French validation of the Foot Function Index (FFI). Reliability of pain scales in the assessment of literate and illiterate patients with rheumatoid arthritis. Revalidation of the original Cedars-Sinai health-related quality of life in rheumatoid arthritis questionnaire. Determining minimally important changes in generic and disease-specific health-related quality of life questionnaires in clinical trials of rheumatoid arthritis. Use of Condition-Specific Patient-Reported Outcome Measures in Clinical Trials among Patients with Wrist Osteoarthritis: A Systematic Review A comparison of the full and short versions of the Arthritis Impact Measurement Scales. Which outcome measures should be used in rheumatoid arthritis clinical trials? Clinical and quality-of-life measures' responsiveness to treatment in a randomized controlled trial. A comparison of health-related quality-of-life measures for rheumatoid arthritis research. The Auranofin Cooperating Group. Psychometric Comparison of the PROMIS Physical Function CAT With the FAAM and FFI for Measuring Patient-Reported Outcomes Development and validation of the European League Against Rheumatism response criteria for rheumatoid arthritis. Comparison with the preliminary American College of Rheumatology and the World Health Organization/International League Against Rheumatism Criteria. Evaluation of joint mobility in rheumatoid arthritis trials: the value of the EPM-range of motion scale. An empirical evaluation of the SF-12, SF-6D, EQ-5D and Michigan Hand Outcome Questionnaire in patients with rheumatoid arthritis of the hand
OBJECTIVE This study vali date d a brief measure of fatigue in rheumatoid arthritis ( RA ) , the Functional Assessment of Chronic Illness Therapy ( FACIT ) Fatigue Scale . METHODS The FACIT Fatigue was tested along with measures previously vali date d in RA : the Multidimensional Assessment of Fatigue ( MAF ) and Medical Outcomes Study Short-Form 36 ( SF-36 ) Vitality . The sample included 636 patients with RA enrolled in a 24 week double blind , r and omized clinical trial ( RCT ) of adalimumab versus placebo . RESULTS The FACIT Fatigue showed good internal consistency ( alpha = 0.86 to 0.87 ) , strong association with SF-36 Vitality ( r = 0.73 to 0.84 ) and MAF ( r = -0.84 to -0.88 ) , and the ability to differentiate patients according to clinical change using the American College of Rheumatology ( ACR ) response criteria ( ACR 20/50/70 ) . Psychometric performance of the FACIT Fatigue scale was comparable to that of the other 2 fatigue measures . A minimally important difference in FACIT Fatigue change score of 3 - 4 points was confirmed in a separate sample of 271 patients with RA enrolled in a second double blind RCT of adalimumab versus placebo . CONCLUSION The FACIT Fatigue is a brief , valid measure for monitoring this important symptom and its effects on patients with RA OBJECTIVE To determine the reliability , validity , and responsiveness of the modified Kap and ji index ( MKI ) . DESIGN Prospect i ve study . A cohort of patients planned for surgery of the wrist and /or fingers was evaluated within 48 hours before surgery and at least 6 months after surgery . SETTING Patients were in hospitalized or private care in France . PARTICIPANTS Patients with rheumatoid arthritis according to criteria of the American College of Rheumatology . Forty-two patients ( 36 women ; mean age , 57.5y ; range , 22 - 80y ) were included in the reliability study . Fifty patients ( 42 women ; mean age , 54.18y ; range , 19 - 77y ) were included in the validity study . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Clinical outcome measures included the MKI , the overall mobility score of the wrist and fingers , the finger mobility score , a visual analog scale ( VAS ) of pain in the h and s and wrists , morning stiffness duration , total score of tenderness , total score of swelling , grip and pinch strength , the H and Functional Index ( HFI ) , and the Cochin rheumatoid h and disability scale . Reliability was studied with the intraclass correlation coefficient ( ICC ) and the Bl and and Altman method . Convergent and divergent validity were assessed with the Spearman correlation coefficient . Responsiveness was assessed by the paired t test , the effect size , and the st and ardized response mean ( SRM ) . RESULTS Interobserver reliability was good with an ICC of.90 , and the Bl and and Altman analysis showed homogeneous distribution of the differences , with no systematic trend . The MKI correlated well with the other mobility measures ( HFI , the finger mobility score measured with the finger goniometer ) , indicating a good convergent validity , and the expected divergent validity with the other outcome measures ( grip and pinch strength , total score of swelling , total score of Ritchie Articular Index , Cochin scale , VAS of pain ) was observed . The 50 patients in the validity study were evaluated twice , before and after surgery , at a mean interval + /- st and ard deviation of 7.16+/-2.10 months ( range , 6 - 15mo ) . Thirty-six patients ( 72 % ) were very satisfied or satisfied with the results of surgery , 7 ( 14 % ) were not satisfied or dissatisfied , and 7 ( 14 % ) were dissatisfied or very dissatisfied . The SRM and effect size values of the MKI were -.19 and -.10 , respectively . Individual changes in the score had the best correlation ( r(s)=.51 ) with overall patient satisfaction . CONCLUSIONS The MKI has excellent validity and reliability . Individual changes in the score are clinical ly relevant . This index can be used in clinical practice and in therapeutic trials ; it needs further study concerning its use for h and surgery Objective : To compare the measurement properties of the Modified Health Assessment Question naire [ MHAQ ] , the SF-36 ® Health Survey 10 item Physical Functioning scale [ PF10 ] , and scores from an item response theory ( IRT ) based scale combining the two measures . Study Design : Rheumatoid arthritis ( RA ) patients ( n = 339 ) enrolled in a multi-center , r and omized , double-blind , placebo-controlled trial completed the MHAQ and the SF-36 pre- and post-treatment . Psychometric analyses used confirmatory factor analysis and IRT models . Analyses of variance were used to assess sensitivity to changes in disease severity ( defined by the American College of Rheumatism ( ACR ) ) using change scores in MHAQ , PF10 , and IRT scales . Analyses of covariance were used to assess treatment responsiveness . Results : For the entire score range , the 95 % confidence interval around individual patient scores was smaller for the combined ( total ) IRT based scale than for other measures . The MHAQ and PF10 were about 70 % and 50 % as efficient as the total IRT score of physical functioning in discriminating among ACR groups , respectively . The MHAQ and PF10 were also less efficient than the total IRT score in discriminating among treatment groups . Conclusions : Combining scales from the two short forms yields a more powerful tool with greater sensitivity to treatment response To assess the sensitivity of the Arthritis Impact Measurement Scales ( AIMS ) , we analyzed data from 3 clinical trials . One trial involving 255 patients with rheumatoid arthritis ( RA ) was a 12-week , r and omized controlled trail of diclofenac , naproxen , and aspirin . Two trials were open-label studies of 24 weeks duration that included 165 RA and 355 osteoarthritis ( OA ) patients , all of whom were treated with diclofenac .  In addition to the AIMS , tender joint count , morning stiffness , and erythrocyte sedimentation rate were used as outcome measures in the trials . The AIMS results showed substantial improvements in Physical Function , Psychological Status , and Pain , as well as in overall Arthritis Impact . These improvements were detected by the time of the initial outcome assessment at 4 weeks or 8 weeks , and were detected in patients with either OA or RA . These AIMS results closely parallel improvements shown by traditional clinical measures , and demonstrate that the AIMS health status measure is sensitive to improvements in OA as well as in RA . The AIMS also detects responses produced by therapy with nonsteroidal antiinflammatory drugs ( NSAIDs ) , and these improvements can be demonstrated in as short a treatment time as 4 weeks . These findings confirm the utility of the AIMS for assessing outcome in rheumatic disease studies , and they have implication s for the design of future clinical trials of NSAIDs The Medical Outcomes Study Short Form-36 ( SF-36 ) is a widely used measure of generic health related quality of life . The purpose of this study is to establish the validity and reliability of the SF-36 , Taiwan Version , when applied to a sample of elderly patients with hip fracture in Taiwan . Data from two sample s were used , the first sample ( n=87 ) from a prospect i ve descriptive study for testing psychometric scaling assumptions , scale responsiveness and criterion validity , and the second sample ( n=69 ) from a clinical trial for examining the validity of the differences in the group . The SF-36 Taiwan version demonstrated good evidence of supporting the scaling assumption . Cronbach ’s alpha coefficients above 0.70 for all scales support the internal consistency . The Physical Function ( PF ) scale had an effect size of 0.88 from months 1 to 3 , and 0.59 from months 3 to 6 after discharge , which appears to have the best responsiveness to clinical changes . Notable floor and ceiling effects ( > 15 % ) for Role Emotion ( RE ) , Role-Physical ( RP ) and PF scales were found . High correlation of 0.62 between the PF and measures of activities of daily living ( ADLs ) , and between RP and instrumental activities of daily living ( IADLs ) ( 0.63 ) supports the construct validity . Significantly higher performance in most SF-36 scales in elders without risk for depression than those who were at risk supported the validity of the group differences . In its current form , the SF-36 Taiwan version demonstrated good reliability and validity as applied to patients with hip fracture OBJECTIVE French validation of the Foot Function Index ( FFI ) , self- question naire design ed to evaluate rheumatoid foot according to 3 domains : pain , disability and activity restriction . METHODS The first step consisted of translation/back translation and cultural adaptation according to the vali date d methodology . The second stage was a prospect i ve validation on 53 patients with rheumatoid arthritis who filled out the FFI . The following data were collected :  pain ( Visual Analog Scale ) , disability ( Health Assessment Question naire ) and activity restrictions ( McMaster Toronto Arthritis question naire ) . A test/retest procedure was performed 15 days later . The statistical analyses focused on acceptability , internal consistency ( Cronbach 's alpha and Principal Component Analysis ) , test-retest reproducibility ( concordance coefficients ) , external validity ( correlation coefficients ) and responsiveness to change . RESULTS The FFI-F is a culturally acceptable version for French patients with rheumatoid arthritis . The Cronbach 's alpha ranged from 0.85 to 0.97 . Reproducibility was correct ( correlation coefficients>0.56 ) . External validity and responsiveness to change were good . CONCLUSION The use of a rigorous methodology allowed the validation of the FFI in the French language ( FFI-F ) . This tool can be used in routine practice and clinical research for evaluating the rheumatoid foot . The FFI-F could be used in other pathologies with foot-related functional impairments The assessment of a measure of chronic pain , should be reliable , valid and sensitive to change . Our study evaluated the reliability of 3 pain scales , visual analogue scale ( VAS ) , numerical rating scale ( NRS ) and verbal rating scale ( VRS )  in literate and illiterate patients with rheumatoid arthritis ( RA ) . Patients with RA attending an outpatient rheumatology clinic were interviewed and asked to score their pain levels on the 3 pain scales . The scales were presented in r and om order , twice , before and just after a regular medical consultation . Ninety-one patients were studied ( 25 illiterate and 66 literate ) . The Pearson product moment correlation between first and second assessment was 0.937 for VAS , 0.963 for NRS and 0.901 for VRS in the literate patient group and 0.712 for VAS , 0.947 for NRS and 0.820 for VRS in the illiterate patient group . These results indicate that the NRS has the higher reliability in both groups of patients OBJECTIVE To assess the psychometric characteristics of the original 33-item Cedars-Sinai Health-Related Quality of Life in Rheumatoid Arthritis Question naire ( O-CSHQ-RA ) and 11-item CSHQ-RA Short Form ( SF ) using a representative population of patients with rheumatoid arthritis ( RA ) from 55 sites across the United States . METHODS Data were from a 24-week multicenter , open-label , single-arm study of 312 RA patients receiving anakinra .  Cronbach 's alpha coefficient was used to indicate the internal consistency . Test-retest reliability was assessed by establishing the intraclass correlation coefficient ( ICC ) for screening and baseline visit responses . Convergent validity was tested with the Pearson correlation coefficient . Analysis of variance was performed to determine discriminant validity . A Wilcoxon signed-rank test and analysis of covariance were used to assess the responsiveness . A discriminant function was generated to determine the clinical ly meaningful change . RESULTS Test-retest reliability was demonstrated for both versions of the CSHQ-RA , with ICC ranging from 0.82 to 0.94 . Cronbach 's alpha coefficients were > or = 0.9 , indicating good internal consistency . Pearson correlations between health-related quality of life instruments and CSHQ-RA measures ranged from -0.33 to -0.73 and 0.39 to 0.76 , demonstrating good convergent validity . Scores on both versions of the CSHQ-RA differed significantly ( p < 0.0001 ) for patients with different levels of physical disability as measured by the Stanford Health Assessment Question naire . Both instruments were responsive to differences in patient health as measured by the general health question ( p < 0.0001 ) . Clinical ly meaningful changes were calculated for all 5 domains of the O-CSHQ-RA ( 6.9 - 14.0 ) and the overall O-CSHQ-RA SF ( 12.7 ) . CONCLUSION These results support the validity and reliability of both the original CSHQ-RA and the 11-item CSHQ-RA SF when tested in a representative patient population OBJECTIVE To define clinical ly meaningful changes in 2 widely used health-related quality of life ( HQL ) instruments in studies of patients with rheumatoid arthritis ( RA ) . METHODS Patients with RA ( n = 693 ) who were enrolled in 2 double-blind , placebo-controlled clinical trials completed the Short Form 36 ( SF-36 ) modified health survey and the Health Assessment Question naire ( HAQ ) disability index at baseline and 6-week followup assessment s. Data on 5 RA severity measures were also collected at baseline and at 6 weeks ( patient and physician global assessment s , joint swelling and tenderness counts , and global pain assessment ) . Comparison of changes in the SF-36 scales and HAQ scores was made between groups of patients known to differ in the level of change on each RA severity measure . RESULTS With few exceptions , changes in the SF-36 and HAQ scores were different between patients who differed in the level of change on each RA severity measure . Changes in the SF-36 and HAQ scores were more strongly related to changes in the patient and physician global assessment s and patient pain assessment than to changes in the joint swelling and tenderness counts . CONCLUSION Based on these results , minimally important changes in the SF-36 scales and HAQ disability scores were determined , which will be useful in interpreting HQL results in clinical trials Background . This paper aim ed to identify condition-specific patient-reported outcome measures used in clinical trials among people with wrist osteoarthritis and summarise empirical peer- review ed evidence supporting their reliability , validity , and responsiveness to change . Methods . A systematic review of r and omised controlled trials among people with wrist osteoarthritis was undertaken . Studies reporting reliability , validity , or responsiveness were identified using a systematic reverse citation trail audit procedure . Psychometric properties of the instruments were examined against predefined criteria and summarised . Results . Thirteen clinical trials met inclusion criteria . The most common patient-reported outcome was the disabilities of the arm , shoulder , and h and question naire ( DASH ) . The DASH , the  Michigan H and Outcomes Question naire ( MHQ ) , the  Patient Evaluation Measure ( PEM ) , and the  Patient-Reported Wrist Evaluation ( PRWE ) had evidence supporting their reliability , validity , and responsiveness . A post-hoc review of excluded studies revealed the AUSCAN Osteoarthritis H and Index as another suitable instrument that had favourable reliability , validity , and responsiveness . Conclusions . The DASH , MHQ , and AUSCAN Osteoarthritis H and Index instruments were supported by the most favourable empirical evidence for validity , reliability , and responsiveness . The PEM and PRWE also had favourable empirical evidence reported for these elements . Further psychometric testing of these instruments among people with wrist osteoarthritis is warranted This study examined the validity and reliability of full and short versions of the Arthritis Impact Measurement Scales ( AIMS ) .  One hundred fifty-five patients with Rheumatoid Arthritis followed at a University Hospital Rheumatology Clinic completed the full AIMS at baseline , 6 months , 12 months , and 18 months . After reducing the 45-item AIMS to 22 , alpha reliabilities and test-retest correlations showed that , with the exception of test-retest correlations for mobility at 6 months and for pain at 12 and 18 months , the full and short scales were comparably reliable . Convergent validity correlations with theoretically related scales were also comparable . However , some of the short scales did not detect the same differences over time that the full scales did . Specifically , the short mobility , pain , anxiety , and depression scales were not as sensitive to change as the full scales . Except for these four scales , the short version appears to be a viable alternative for use by health professionals and research ers OBJECTIVE To determine the discriminant validity of the core set of outcome measures proposed by the American College of Rheumatology ( ACR ) and the Outcome Measures in Clinical Trials ( OMERACT ) conference committee to be used in clinical trials of rheumatoid arthritis ( RA ) . METHODS Utilizing data from a multicenter r and omized double-blind clinical trial of low-dose cyclosporine and placebo in RA , we estimated the relative efficiency ( RE ) of measures to detect a treatment effect ( relative to tender joint count , which was assigned a value of 1 ) . Four pain measures ( 10-cm visual analog scale [ VAS ] , 5-point categorical scale , Health Assessment Question naire [ HAQ ] pain index , Arthritis Impact Measurement Scales [ AIMS ] pain score ) and 3 quality -of-life measures ( Problem Elicitation Technique [ PET ] , HAQ , AIMS )  were compared . RESULTS Physician and patient global measures were the most responsive instruments , although neither was statistically superior to tender joint count . Swollen joint count , grip strength , pain measured on a 10-cm VAS , and functional status as measured by the PET and HAQ were all of intermediate responsiveness . Morning stiffness , 5-point pain scale , and erythrocyte sedimentation rate were the least responsive instruments . CONCLUSION This study provides further evidence to support the core set of outcome measures proposed by the ACR and OMERACT Twenty-eight instruments measuring pain , clinical , functional , and global characteristics  were administered to 303 patients in a six-month r and omized clinical trial of auranofin and placebo in the treatment of patients with rheumatoid arthritis . The instruments were compared with respect to their responsiveness in detecting a treatment effect , the time involved in administering the instrument , the need for the presence of an interviewer , and ease of administration . The instruments ' ability to detect a treatment effect was the deciding characteristic in the clinical , pain , and global categories in choosing the preferred instrument . The counts of tender and swollen joints were found to be the most responsive clinical measures , the 10-cm pain line was the most responsive and the fastest to administer of the pain instruments , and the categorical self- assessment of arthritis was the most responsive global measure . In the functional ability category , the Health Assessment Question naire ( HAQ ) , the Keitel Functional Assessment , and the Quality of Well-Being ( QWB ) Question naire were equally responsive . The HAQ was the shortest and the only self-administered question naire . The QWB has had the most extensive validation work but was a complex instrument requiring intensive interviewer training . The Keitel was the most time-consuming instrument , but had the advantage of high interobserver agreement . The design of future trials can be guided by the information obtained in this study on their relative efficiencies and ease of use Background : Selecting optimal patient-reported outcome ( PRO ) instruments is critical to improving the quality of health care . The purpose of this study was to compare the reliability , responsiveness , and efficiency of three PRO measures : the Foot and Ankle Ability Measure – Activity of Daily Living subscale ( FAAM_ADL ) , the Foot Function Index 5-point verbal rating scale ( FFI-5pt ) , and the PROMIS Physical Function computerized adaptive test ( PF CAT ) . Methods : Data were aggregated from 10 clinical sites in the AOFAS ’s National Orthopaedic Foot and Ankle Research ( OFAR ) Network from 311 patients who underwent elective surgery for a disorder of the foot or ankle . Patients were administered the FAAM_ADL , FFI-5pt , and PF CAT at their preoperative visit and at 6 months after surgery . Reliabilities were evaluated using a Rasch model . Responsiveness was calculated using paired sample s t test and efficiency was recorded as number of seconds to complete the instrument . Results : Similar reliabilities were found for the three instruments . Item reliabilities for FAAM_ADL , FFI-5pt , and PF CAT were all .99 . Pearson reliabilities for FAAM_ADL , FFI-5pt , and PF CAT were .95 , .93 , and .96 , respectively . On average , patients completed the FAAM_ADL in 179 seconds , the FFI-5pt in 194 seconds , and the PF CAT in 44 seconds , ( P < .001 ) . The PF CAT and FAAM_ADL showed significant improvement ( P = .01 and P = .001 , respectively ) in patients ’ physical function after treatment ; the FFI-5pt did not show improvement . Conclusions : Overall , the PF CAT performed best in terms of reliability , responsiveness , and efficiency in this broad sample of foot and ankle patients . It can be a potential replacement for the conventional PRO measures , but further validation is needed in conjunction with the PROMIS Pain instruments . Level of Evidence : Level I , prospect i ve comparative outcome study OBJECTIVE To vali date the European League Against Rheumatism ( EULAR ) , the American College of Rheumatology ( ACR ) , and the World Health Organization (WHO)/International League Against Rheumatism ( ILAR ) response criteria for rheumatoid arthritis ( RA ) . METHODS EULAR response criteria were developed combining change from baseline and level of disease activity attained during follow up . In a trial comparing hydroxychloroquine and sulfasalazine , we studied construct ( radiographic progression ) , criterion ( functional capacity ) , and discriminant validity . RESULTS EULAR response criteria had good construct , criterion , and discriminant validity , ACR and WHO/ILAR criteria showed only good criterion validity . CONCLUSION EULAR response criteria showed better construct and discriminant validity than did the ACR and the WHO/ILAR response criteria for RA OBJECTIVE Evaluation of joint range of motion ( ROM )  is important in the therapeutic approach to patients with rheumatoid arthritis ( RA ) . The reliability , construct validity and sensitivity to change of the Escola Paulista de Medicina (EPM)--range of motion scale that measures 10 distinct movements of small and large joints were examined . METHODS Fifty patients with active RA who were participating in an inpatient multidisciplinary treatment program were examined by 2 investigators . Twenty-five of the patients were examined both at admission and at discharge from the hospital . RESULTS The mean EPM-ROM score at study entry was 11.52 ( SD + /- 3.80 ) . The intra and inter-observer reliability of the EPM-ROM scale was high , with correlations of r = 0.91 and r = 0.85 , respectively . There was a good correlation between the EPM-ROM scale and measures of functional ability . Correlations with measures of disease activity were poor . After a mean duration of the treatment program of 4.2 weeks , patients generally improved in variables of functional status and disease activity . The improvement of the EPM-ROM score ( mean difference 1.58 , 95 % CI 0.84 - 2.32 ) was generally larger than improvement in other variables of functional status . CONCLUSION The EPM-ROM scale is a reliable instrument , and according to its correlation with measures of functional status , relevant to the performance of activities of daily living . It showed a good response to improvement of functional status and disease activity and was more sensitive to changes than other variables of functional status Background The aim of this study was to assess the psychometric properties , namely acceptability , validity , reliability , interpretability and responsiveness of the EuroQol EQ-5D ( EQ-5D visual analogue ( VAS ) and EQ-5D ( utility ) ) , Short Form 12 Dimensions ( SF-12 ) , SF-6D and Michigan H and Outcome Question naire ( MHQ ) in patients with rheumatoid arthritis ( RA ) of the h and . Methods The empirical investigation was based upon data from a r and omised controlled trial of 488 adults with rheumatoid arthritis who had pain and dysfunction of the h and s and /or wrists . Participants completed the EQ-5D , SF-12 and MHQ at baseline and at 4 and 12 months follow up . Acceptability was measured using completion rates over time ; construct validity using the “ known groups ” approach , based on pain troublesomeness ; convergent validity using spearman ’s rho correlation ( ρ ) ; reliability using internal consistency ( Cronbach ’s alpha ) ; interpretability using minimal important differences ( MID ) ; and responsiveness using effect sizes and st and ardised response means ( SRM ) stratified by level of self-rated improvement in h and and wrist function or level of self-rated benefit and satisfaction from trial treatments . Results At baseline , the study population had a mean age of 62.4 years , a mean MHQ score of 52.1 and included 76 % women . The EQ-5D ( utility ) had the highest completion rates across time points . All instruments discriminated between pre-specified groups based on pain troublesomeness . Convergent validity analysis indicated that the MHQ score correlated strongly with the EQ-5D ( ρ = 0.65 ) and SF-6D ( ρ = 0.63 ) utility scores . The MHQ was most responsive at detecting change in indicators of RA pain severity between baseline and 4 months , whilst minimal important differences varied considerably across PROMs . Conclusions The instruments evaluated in this study displayed varying psychometric properties in the context of RA of the h and . The selection of a preferred instrument in evaluative studies should ultimately depend on the relative importance placed on individual psychometric properties and the importance placed on generation of health utilities for economic evaluation purpose
Conclusion Based on this literature review , the disease-specificHAQ and the generic SF-36 can currently be most confidently recommended to measure PF in RA for most research purpose s. The HAQ , however , was frequently associated with considerable ceiling effects while the SF-36 has limited content coverage .
Background The aim of this study was to systematic ally review the content validity and measurement properties of all physical function ( PF ) scales which are currently vali date d for use with patients with rheumatoid arthritis ( RA ) .