Development and validation of a muscular dystrophy-specific functional rating scale Measuring disability and function in older women: psychometric properties of the late-life function and disability instrument. Establishing the minimal number of items for a responsive, valid, health-related quality of life instrument. Validity of a brief outpatient functional assessment measure. Reliability, validity, and responsiveness of the modified Kapandji index for assessment of functional mobility of the rheumatoid hand. Revalidation of the original Cedars-Sinai health-related quality of life in rheumatoid arthritis questionnaire. Clinimetric Properties of the Motor Activity Log for the Assessment of Arm Use in Hemiparetic Patients French validation of the Foot Function Index (FFI). Evaluation of Medical Outcomes Study Short Form-36 Taiwan version in assessing elderly patients with hip fracture Reliability and validity of shoulder function outcome measures in people with a proximal humeral fracture Reliability and Validity of 6 Measures of Pain, Function, and Disability for Ankle Arthroplasty and Arthrodesis Validation and use of performance measures of functioning in a non-disabled older population: MacArthur studies of successful aging Functional index-2: Validity and reliability of a disease-specific measure of impairment in patients with polymyositis and dermatomyositis. Comparison of performance-based and patient-reported measures of function in anterior-cruciate-ligament-deficient individuals. Validity of the Functional Gait Assessment in Patients With Parkinson Disease: Construct, Concurrent, and Predictive Validity Validation of Questionnaires on Physical Function Estimation of a numerical value for joint damage-related physical disability in rheumatoid arthritis clinical trials
Objective : To develop a reliable and valid new rating scale for measuring the functional impact of muscular dystrophy . Design : Prospect i ve and longitudinal investigation . Setting : Three academic medical centres in Taiwan and the Muscular Dystrophy Association of Taiwan . Measures : The Brooke Scale , the Vignos Scale , the Barthel Index , muscular strength , contracture severity , and predicted forced vital capacity ( FVC% ) . Methods : Scale development was in three stages . In stage I , a preliminary pool of 53 items was generated from patient interviews ( n-/25 ) , literature review , existing functional rating scales and expert opinion . In stage II , these items were administered to 85 patients with muscular dystrophy . The result ing data were analysed to construct a rating scale ( the Muscular Dystrophy Functional Rating Scale , MDFRS ) that encompassed four unidimensional constructs : mobility , basic activities of daily living , arm function and impairment . In stage III , the measurement properties of this rating scale were assessed in 121 muscular dystrophy patients different from those examined with the preliminary instrument . Results : Internal consistency reliability was excellent for all domains of the final 33-item scale , with values of Cronbach ’s alpha ranging from 0.84 to 0.97 . Intraclass correlation coefficients for test-retest and inter-rater reliability were 0.99 for all domains of the MDFRS . The MDFRS showed moderate to high correlations with a range of functional rating scales measuring similar aspects and impairment parameters ( Spearman ’s rho=0.65 - 0.91 ; P<0.001 , each ) . Confirmatory factor analysis supported a unitary construct of the four-dimensional MDFRS . The MDFRS had small floor and ceiling effects in the study sample s. Sensitivity to change was confirmed by large st and ardized response means for the MDFRS total score . Conclusions : The MDFRS is a reliable and valid disease-specific measure of functional status for patients with muscular dystrophy BACKGROUND The recent development of the Late-Life Function and Disability Instrument ( LL-FDI ) was an important contribution to the measurement of function and disability in older adults . The present study examined the psychometric properties and construct validity of the LL-FDI measure in a sample of older women . METHODS Older black ( n = 81 ) and white ( n = 168 ) women completed the LL-FDI  , several measures of physical function , and physical activity measures , and had their body mass index assessed at baseline of an ongoing prospect i ve study . Confirmatory factor analyses ( CFA ) and correlational analyses were used to examine factorial and construct validity of the measure . RESULTS The CFA , using an iterative model modification technique , result ed in an acceptable 15-item solution for the function component and an 8-item solution for the disability component . This abbreviated instrument demonstrated high correlations with the original scales . Construct validity for the LL-FDI was supported . Participants who demonstrated better physical function , reported being more active , and had lower body mass index reported less disability and less difficulty with function on the LL-FDI . CONCLUSIONS The LL-FDI appears to be an effective instrument for assessing function and disability in older women , and the abbreviated version reported here may prove useful in certain circumstances due to its brevity . However , continued determination of the construct validity of the complete and abbreviated scales is recommended Reducing the number of items in a health-related quality of life instrument will enhance efficiency . However , it is important to maintain measurement properties . We determined the effect of reducing items from each domain ( dyspnea , fatigue , emotion and mastery ) of the 20-item Chronic Respiratory Question naire ( CRQ ) .  Three r and omized trials of respiratory rehabilitation provided data . We removed items one at a time from each domain in three orders : by item impact , item responsiveness , and at r and om . Responsiveness , test-retest reliability and construct validity were evaluated at each step . Responsiveness and reliability , evaluated by intraclass correlation coefficients ( ICC ) , were reduced marginally as the number of items was reduced to two items per domain . The deterioration was greatest when reducing from two items to one . To detect a particular effect , sample size would increase by about 10 % when reducing the number of items in a domain to 2 . Construct validity showed a more marked deterioration . Reducing to two items per domain would maintain responsiveness and reliability of the CRQ at an acceptable level , with a trade-off of reduced construct validity and increase in sample size requirements Aspects of validity are investigated with a brief functional assessment measure among out patients undergoing rehabilitation for musculoskeletal problems . The Medical Rehabilitation Follow Along measure ( MRFA ) currently has screening , musculoskeletal , neurologic , and multiple sclerosis forms . In this study , the 31-item musculoskeletal form of the MRFA is compared with and contrasted to a measure of general health status , the Medical Outcomes Trust SF-36 . Content , construct , and criterion validity are addressed using scale scores before ( n = 94 ) and after ( n = 48 ) outpatient rehabilitation .  Scale scores are compared with therapists ' ratings of improvement . The results provide support for the validity of inferences made from scale scores of the MRFA for persons with musculoskeletal problems . Applications of the MRFA , including screening , monitoring , and outcome assessment are discussed for clinical management , measuring treatment effectiveness , and program evaluation 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 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 Background and Purpose — The Motor Activity Log ( MAL ) is a semistructured interview for hemiparetic stroke patients to assess the use of their paretic arm and h and ( amount of use [ AOU ] ) and quality of movement [ QOM ] ) during activities of daily living . Scores range from 0 to 5 . The following clinimetric properties of the MAL were quantified : internal consistency ( Cronbach α ) , test – retest agreement ( Bl and and Altman method ) , cross-sectional construct validity ( correlation between AOU and QOM and with the Action Research Arm [ ARA ] test ) , longitudinal construct validity ( correlation of change on the MAL during the intervention with a global change rating [ GCR ] and with change on the ARA ) , and responsiveness ( effect size ) . Methods — Two baseline measurements 2 weeks apart and 1 follow-up measurement immediately after 2 weeks of intensive exercise therapy either with or without immobilization of the unimpaired arm ( forced use ) were performed in 56 chronic stroke patients . Results — Internal consistency was high ( AOU : α=0.88 ; QOM : α=0.91 ) . The limits of agreement were −0.70 to 0.85 and −0.61 to 0.71 for AOU and QOM , respectively . The correlation with the ARA score ( Spearman ρ ) was 0.63 ( AOU and QOM ) . However , the improvement on the MAL during the intervention was only weakly related to the GCR and to the improvement on the ARA , Spearman ρ was between 0.16 and 0.22 . The responsiveness ratio was 1.9 ( AOU ) and 2.0 ( QOM ) . Conclusion — The MAL is internally consistent and relatively stable in chronic stroke patients not undergoing an intervention . The cross-sectional construct validity of the MAL is reasonable , but the results raise doubt about its longitudinal construct validity 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 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 Abstract Purpose : Investigate test -- retest reliability and validity of five shoulder outcome measures in people during their active rehabilitation after a shoulder fracture . Method : This prospect i ve longitudinal study assessed shoulder function in 20 people ( 16 women , mean age 68.1 years ) with surgical or conservative management at 6 , 12 and 13 weeks post proximal humeral fracture using three patient-reported ( Disabilities of Arm , Shoulder and H and ; Oxford Shoulder Score ; Subjective Shoulder Value ) and two clinician-administered ( Constant Score ; UCLA Shoulder score ) outcome measures . Results : Content analysis categorised items into multiple domains of functioning for each outcome measure . Construct validity testing between measures found moderate to strong correlations ( r = 0.43–0.92 ) . Longitudinal validity ( responsiveness ) , represented by correlations between change scores , was moderate to strong ( r = 0.44–0.83 ) . Although ICCs2,1 for test – retest reliability ranged from 0.75 to 0.93 , Limits of Agreement between measurements were relatively wide ( 10–23 % of available range of scores ) . Minimal clinical ly important difference estimates varied between anchor- and distribution-based methods . Conclusions : The five outcome measures assessing shoulder function provided values for reliability and validity that meet measurement requirements for use in groups of people after a proximal humeral fracture . However , the use of these outcome measures might be limited by low absolute agreement between measurements and their content covering multiple domains of functioning . Implication s for Rehabilitation Linking the International Classification of Functioning , Disability and Health ( ICF ) to the content of common shoulder function outcome measures showed that multiple domains of functioning are combined into a single score . This might not be preferred for measurement of the single construct of “ shoulder function ” . Currently available shoulder function outcome measures may not be sufficiently reliable to monitor change in an individual after a proximal humeral fracture during the rehabilitation phase Background : Patient-reported outcome measures are increasingly used evaluating clinical care . Many measures used to assess operative hindfoot interventions vary in content , and some have not been psychometrically vali date d in this population . The purpose of this study was to compare measurement properties of  6 lower-extremity patient-reported outcome measures  , and to evaluate their reliability and validity in light of patients ’ preferences . Methods : Cross-sectional survey of 42 preoperative and 100 postoperative patients completed 6 lower-extremity outcome measures  on 2 occasions : Foot Function Index ( FFI ) , Ankle Osteoarthritis Scale ( AOS ) , patient-reported items of the  American  Orthopaedic Foot & Ankle Society Question naire ( AOFAS ) , Lower Extremity Functional Scale ( LEFS ) , Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) , and the Short Musculoskeletal Function Assessment ( SMFA ) , as well as measures of preference , and symptoms . Results : Internal consistency was good to excellent for all scales and subscales ( α = .84-.97 ; ICC [ 2,1 ] = .81-.96 ) . Correlations between scales ranged from .50 ( WOMACStiffness and FFIActivity Limitations ) to .92 ( LEFS and SMFAOverall , WOMACPain and AOSOverall , FFIOverall and AOFASOverall ) . Higher correlations occurred within instruments ( r = .97 AOSPain and AOSOverall ) and between similar subscales from different instruments ( r = .91 WOMACPain and AOSPain ) . Construct validity showed moderate to high correlations to global ratings of Pain , Stiffness , and difficulty performing Daily Activities . The highest correlations ( r > .75 ) occurred between Pain and AOSOverall ( r = .84 ) , stiffness and WOMACStiffness ( r = .81 ) , and Daily Activities and AOSDisability ( r = .87 ) . Patients rated instruments by preference . FFI , WOMAC , LEFS , and SMFA rated favorably for length . FFI , WOMAC , LEFS , and AOFAS rated high for underst and ability . FFI was rated by postoperative patients as most likely to capture change due to surgery . SMFA rated the best overall . Conclusions : Direct comparison of instruments revealed similarity between scales in construct validity and reliability . Patient preferences supported the use of these scales . Foot-specific instruments offered no clear advantage over lower-extremity instruments . Level of Evidence : Level II , prospect i ve comparative study Assessment of physical functioning in older persons has generally focused on identifying and characterizing subjects at the disabled end of the functional spectrum . This paper examines the validity of objective , st and ardized performance measures of physical functioning in characterizing the hierarchy of functioning in non-disabled , higher functioning older persons . Data are from 1192 participants aged 70–79 years in The MacArthur Research Network on Successful Aging Field Study . Participants were drawn from three communitybased population s and represented the upper tertile of functioning , based on cognitive and physical screening assessment s. The cohort showed a great deal of heterogeneity on most of the performance measures of functioning that were used . Several analyses provided evidence that this variability was not r and om and that the performance measures were valid measures of functioning in this cohort : 1 ) individual performance measures showed a moderate degree of correlation with each other ; 2 ) a summary measure of performance showed an association with chronic diseases and other factors known to be associated with health status ; and 3 ) a larger group than expected by chance alone was found to be functioning at the very highest level . ( Aging Clin . Exp . Res . 6 : 410 - 419 , 1994 OBJECTIVE To revise the content of the Functional Index in myositis ( FI ) and to evaluate measurement properties of a revised FI . METHODS Previously performed FI ( n = 287 ) were analyzed for internal redundancy and consistency , and ceiling and floor effects . Content was evaluated and a preliminary revised FI was developed . To evaluate the construct validity of the preliminary revised FI , it was compared with isokinetic measurements of muscular strength and endurance , the Myositis Activities Profile , disease impact on general wellbeing , and creatine phosphokinase levels . Minor adjustments were made and the revised FI was investigated for interrater reliability and intrarater reliability over a 1-week period . After this , some minor , additional adjustments were made leading to the final version , FI-2 . RESULTS Five tasks were removed from the original FI due to ceiling effects . Performance pace and number of repetitions were modified for the remaining tasks . A moderate correlation ( r(s ) = 0.58 ) was found between the shoulder flexion task of the preliminary revised FI and isokinetic measurements of shoulder flexion endurance . Intraclass correlation coefficient ( ICC ) for interrater reliability of the revised FI varied from 0.86 - 0.99 with no systematic differences . ICC for intrarater reliability varied from 0.56 - 0.99 with systematic differences ( P < 0.05 ) between test and retest in 3 of the tasks . The sit-up task was excluded due to low intrarater reliability result ing in the final 7-item FI-2 . There was a good correlation between tasks on the right and left side suggesting that the FI-2 could be performed unilaterally . CONCLUSION The FI-2 is a valid and reliable outcome measure of impairment for patients with polymyositis or dermatomyositis . It is well tolerated and the unilateral FI-2 requires a maximum of 20 minutes to perform . Further evaluation of sensitivity to change and testing in healthy individuals needs to be conducted There is a dearth of reliable and valid instrumentation that measures disability following injury and /or surgery of the knee joint that is responsive to clinical ly significant changes over time . The purpose of this investigation was to determine whether  performance-based or patient-reported measures of function  are more effective in estimating disability in individuals with an anterior-cruciate-ligament (ACL)-deficient knee .  Subjective rating of knee function was used as the criterion measure for disability , and selected performance-based and patient-reported measures were used as estimation variables . Twenty-nine individuals with an ACL-deficient knee participated in this investigation . Step-wise regression analysis revealed that the Cincinnati Knee Scale , Lysholm Knee Scale , and hop index were the most effective estimates of disability . The results demonstrate that patient-reported measures are more related to the patient 's level of disability in individuals with an ACL-deficient knee . More research is necessary to substantiate these findings Background The Functional Gait Assessment ( FGA ) is a vali date d measurement of gait-related activities in certain population s and may be potentially useful to assess balance and gait disorders in patients with Parkinson disease ( PD ) . Objective The purpose of this study was to determine the construct , concurrent , and predictive validity of the FGA in in patients with PD . Design This was a prospect i ve cohort study . Methods One hundred twenty-one in patients with PD were prospect ively enrolled . The FGA and other relevant appraisal s of gait , balance , disease severity , and activities of daily living were performed . Six months later , the patients were interviewed by telephone to have their fall information collected . Principal component analysis was used to determine construct validity . Spearman correlation coefficients were used to determine concurrent validity between the FGA and other measures . Cutoff point , sensitivity , specificity , and positive likelihood ratio were calculated for predictive validity based on the receiver operating characteristic curve . Results One common factor was extracted for construct validity , which cumulatively explained 64.0 % of the total variance . Correlation coefficients for the FGA compared with other measures ranged from .57 to .85 . The cutoff point for predicting falls was 18 , with sensitivity of 80.6 % , specificity of 80.0 % , and positive likelihood ratio of 4.03 . Limitations This study was limited by the length of time of follow-up and self-reports of falls without the requirement of a fall diary . Medication adjustment after the FGA evaluation may have led to a different cutoff score for identifying those patients who were at risk of falling . Conclusions The FGA demonstrated good construct validity in patients with PD . It had moderate to strong correlations with other balance and gait appraisal s. The FGA can be used to predict falls within the subsequent 6 months Data -gathering instruments were used in a r and omized controlled trial , design ed to assess a structured preoperative educational program for elective surgical patients . The key dependent variable was the physical functional capacity of patients following surgery . Question naires were developed to measure physical functioning in the immediate postoperative period , after discharge from hospital , and 10 days and 33 days after surgery . Statistical techniques used to measure interobserver agreement and bias were Bowker 's chi square , Cicchetti 's statistic , the contingency coefficient , Kendall 's Taub , and Kendall 's coefficient of concordance W. The st and ardized question naires permitted classification of patients ' postoperative physical functions with results that agreed highly with the classification done by experienced clinicians who cared for the same patients Background Joint damage is an important outcome in trials of rheumatoid arthritis ( RA ) , usually assessed by Total Sharp Score ( TSS ) . It is currently unknown how it translates numerically into disability by the Health Assessment Question naire ( HAQ ) . Objective To determine the units of HAQ score corresponding to one TSS unit . Methods A short-term observational trial of  glucocorticoids in RA ( the ‘ BEst LIfe with Rheumatoid Arthritis ’ ( BELIRA ) trial ) was evaluated , using r and omised controlled clinical trial ( RCT ) data for confirmation . For each trial arm HAQ , TSS and the Simplified Disease Activity Index ( SDAI ) were assessed . Based on the hypothesis that short-term HAQ changes will mostly be due to changes of disease activity , activity HAQ ( ACT-HAQ ) at end point ( EP ) was determined and remaining disability defined as damage related ( DAM-HAQ ) . Using TSS at EP , the HAQ units corresponding to a TSS unit were estimated . Results In BELIRA , one TSS unit corresponded to a mean of 0.017 HAQ units ; to account for other causes of irreversible disability , the 25th percentile was used : 0.011 HAQ units/TSS unit . In RCT trial arms , the HAQ/TSS were similar ( 0.013 and 0.015 in established and early RA , respectively ; 25th percentile : 0.010 ) . The correlation between DAM-HAQEP and TSS was r=0.829 . Over 5 years , damage would amount to an increase of irreversible HAQ of 0.33 on placebo , 0.13 on disease-modifying antirheumatic drugs ( DMARDs ) and 0.03 on TNF inhibitors+methotrexate ( MTX ) . Conclusion An approach to estimate the numerical relationship between HAQ and damage as 0.01 HAQ points/TSS unit is presented , although the linear relationship may not be generally valid . This allows the assessment of functional correlates of radiographic changes in trials
In general , estimates of construct validity were lower when vali date d against dissimilar constructs , except for instruments measuring impairments in mental functions .
CONCLUSION There is a trend that validation against a similar construct yields higher correlation coefficients than validation against a dissimilar construct .
PURPOSE This paper focuses on the construct validity of instruments measuring impairments in body structures and function in rheumatic disorders .
The objective is : 1 ) to make an inventory of constructs , based on the domains of the International Classification of Functioning , Disabilities and Health problems ( ICF ) , against which instruments measuring impairments in body structures and function were vali date d ; 2 ) to analyse whether validation against a similar construct result ed in higher correlation coefficients than validation against a dissimilar construct .